David Ashton

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Communications Technician

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    • Some beautiful ICs may bring happy memories to some readers and smiles of disbelief to younger ones who missed out on working with these old through-hole components.

    • We've probably all used Google translate on a PC to translate something from another language, but the Google Translate smartphone app is something else.

    • It's entitled "Analog Engineer's Pocket Reference," but a lot of this is applicable across a wide array of disciplines, especially if you have to interface with the real world.

    • In which we discover the various types of resistors, and the way in which these components have evolved over the years.

    • There are a many different ways to make holes in things. Most of them involve drilling or cutting in some way, but there are other techniques.

    • The article says "La description de ce langage est apparue initialement dans 'Les Cerveaux non-humains' " which means "The description of this language appeared initially in 'Non-human Brains' ". Maybe that's why I don't understand it :-) "Non-human Brains" is a book about IT published in 1970. I'd say not much has changed since then..... :-)

    • @Cdhmanning...just spent a happy 10 minutes going through the Wikipedia article on Tommy Flowers. Thanks for that!

    • @Cdhmanning...I remember those 2708s but alas could not find any for this article. They would have made good dangly earrings. I reckon a lot of electronic stuff would make good jevellery - some of the more colorful resistors and caps would certianly look OK....

    • @Antedeluvian...thanks for all the comments...it's good to know I have at least one dedicated reader :-) Your Avago link does not work (don't use brackets when posting - put it on a separate line like this http://www.avagotech.com/docs/AV02-0886EN (especially on Embedded.com which does not let you edit/delete like EET!) There are so many ICs worthy of mention in a column like this. You could do a whole series on IC Widths - from tiny SMD 4- or 6-pin packages up to the monster which was first above (have you seen anything bigger? And also on power packages for things like motor drivers (your L6203) and power amps (think the weird Sanken packages). Thinks - ideas for future blogs..... :-)

    • Nice article Aubrey and nice solutions. You could just use a capacitor from the port to the driver IC - perhaps with a resistor in series, and certainly with a resistor across the driver input - and remember to put a discharge resistor from the port to ground in case the port goes Hi-Z. Simple and crude, but effective if you aren't too fussed about the exact pulse time - you can do your RC calculations and estimate it. You can also drive speakers or piezo sounders like this.

    • As soon as I saw that green circuit board with the bright orange connectors on the header page, I thought "Aubrey!" even though your name was not on it. I've never had the misfortune to fall foul of these undocumented features, though I have seen a few designs which specify the chip type and manufacturer to use for a certain IC. I have also come across undocumented features in programs and products - the most famous of which was the notoriously inaccurate timer on Hewlett-Packard's HP-45 calculators.

    • Jack... " I can’t imagine those young men of the 1940s on missions lasting 8 hours or more." and "...the spark plugs, all 112 of them, have to be changed every 6 flight hours." How did they manage those long missions?? Seriously though, good on you (and your dad)- you both seem to have had good lives, and you can't ask more than that. And I'll second (well, third now) your right to go off-topic whenever you want.

    • Thought about this a bit Max and pure random levels are going to look silly. Think about a candle flame - it has a basic light output which goes up and down a bit but never to zero. I've never tried this before but were I to do so I would start off with a base level - say 50%. I'd then modulate that with a slowly changing random level that would change another 25% either way over a second or two. Then add another faster modulation - around 10% - that would change over around 1/4 second. Put RC filters on all of them so they change relatively gradually, not as steps. Somewhere recently I have seen a flicker simulator - I'll see if I can find it and report....

    • Further to my above post, I found that most of the EA2 5V types are latching, and I can get quite a few (each unit has around 15 of them). Latching ones might be interesting. You put voltage on the coil one way to set them, and the other way to reset them. You should be able to simulate bistables or flip-flops with them? My disposal got put off till Friday, and I think I'm going to set aside some of these, I don't have many latching types around. But they are orange, so no use to Max.... :-)

    • @Elizabeth... "Look for an old PLC or other industrial control. They usually have relays on their I/O." This is true, but they are usually 24V coil relays, Max wants 5V or 12V types. Also, as he told me in an email in response to my below post, he is after the clear plastic case types so you can see the moving parts clicking away. All I can offer is black or bright orange cases....

    • Great stuff Max, you should Write a book. Oh, sorry, you already did (and very good it is too). One thing you may be able to correct. In the gray code series, all parts have a link to the next part at the end, except part 3.

    • @Cdhmanning...they also mention flow meters....I looked up the Wikipedia article on flow meters and some way down it discusses two types of ultrasonic flow meters. they work by using differences in transit time of pulses, or by Doppler effect. In either case differences can be quite small and you'd need a fair bit of precision - though whether the 55pS stated is really necessary I couldn't say...

    • Nice coverage Aubrey. Some years ago I picked up a bunch of LS7210's. I did play around with one on a breadboard and it's a handy chip, the LS7211 which you mention is its big brother I think. The long delays obtainable would be great for a time-limited battery charger for example. But I've never got around to using them :-( There are indeed a large number of devices that a user can choose from...

    • Max... "So, where can I get a lot of small relays very cheaply?" I can get you pretty much as many as you want of these: http://www.okorelays.com/oko/datasheets/47W.pdf Only trouble is, they are 48Volt coils. I seem to remember offering these to you once before and you spurned them..... I may also be able to get you lots of this type (EA2) in 5V or 12V: http://www.farnell.com/datasheets/302394.pdf However they come in latching and non-latching types and I'm not sure what I have...probably non latching but I'd have to check. You need to let me know asap, because they are in some old equipment that is getting chucked out on Tuesday!

    • @Gjsmith...thanks for that...first I have heard of the Microsoft version. It's not like Microsoft to hide their light under a bushel... but then the teaser for google translate was only on the google page for a couple of days.

    • Well, you could get free lighting, just put a fluorescent tube in the ceiling (no connection to electricity required). Oh, and you couldn't switch it off at night....

    • My reaction to this is the same as for "high quality oxygen free data cables" and other such nonsense: (a) There's one born every minute... (b) Why didn't I think of that!!

    • @Max "...who knows where we'll be in 5 or 10 years' time?" Too right. I read a couple of days ago of a guy who was pinned under his car when it fell off the jack. He couldn't move much but managed to activate his iPhone, which had Suri enabled. He got Suri to dial 911 and though he could not hear the dispatcher, he just kept shouting his name and address and what his problem was - and they were able to send assistance to release him. That wouldn't have happened a few years ago either. He swore he'd stick with iPhones for the rest of his life (and get some wheel chocks, hopefully... :-)

    • @antediluvian....and Max has just posted an article on "Augmenting Your Systems With Embedded Vision". Be afraid - be very afraid.... http://www.eetimes.com/author.asp?section_id=216&doc_id=1327615

    • Max...I don't know how this would go in the code size/speed stakes but I would thing that the method proposed by Wnderer on the EETimes version of your original blog is worth a try. here's a link: http://www.eetimes.com/messages.asp?piddl_msgthreadid=47977&piddl_msgid=346074#msg_346074 Basically he uses dot for ones and dash for zeros. The first (MSB) bit of a byte is the opposite of the first element, and you fill the byte with that till you hit the first element. He uses the notion of positive and negative 2's complement bumbers to explain this but I reckon that's complicating it a bit. Let's say you want to send an "A" (.- or 10). the first element is a 1 so you fill the rest of the byte with zeroes (00000010). You look at the first (MSB) bit and it's a zero. So you shift left till you hit a different bit (here bit 7 = 1) and transmit that (one unit flash, one unit space) then the next bit (bit 8 = 0 = three unit flash, one unit space) and then transmit your three unit space before you load the next character. Lets say this is a "B" (-... or 0111). You fill the rest of the byte with ones (11110111). Your MSB is a 1 so you shift left till you hit a zero, then transmit that and all the remaining bits. The nice thing about this is that (a) it's one byte per character (none of my morsels) (b) it's really easy to do in software, all you need is a lookup table which as wnderer points out you can index using (ASCII value - 48) and (c) you can transmit up to 7-element morse characters using this method. He does not say how to do spaces between words but it would be easy to use an all-ones or all-zeroes byte for this, that would be an easy test before you process the character.

    • Max... "First, I wonder what Claude Shannon's reaction would have been if I were to hop into my trusty time machine and take one of Harjit's micro-mice back to the 1950s." At a guess, I would say he'd be amazed (pardon the pun) at how small and fast the electronics had become, but I'm sure he would not bat an eyelid at the solving of the maze - he'd already worked that out. I love this video - Claude Shannon is the unseen hero behind a lot of the stuff that I, as a telecomms techie, use every day (though I'm damn sure that most of my workmates would not even have heard of him). I'd have a rough idea how to program a mouse to get througn a maze, but I'd never have been able to come up with his information theory about how much information you can cram onto a signal. He discovered and developed so much more, as a visit to his Wikipedia article shows: https://en.wikipedia.org/wiki/Claude_Shannon

    • Wwhenever one of these extreme sports guys dies, I have mixed emotions.... part of me says "Dumb ass, it was bound to happen" and another part of me says "He died doing something he loved, and you can't ask for more than that!" The second part usually wins....

    • HI Steve, thanks. Those QM1502 meters seem to be everywhere. Max bought a bunch of them in the states really cheap last year. They are amazingly good value.

    • @Antedeluvian...what you need is one of these http://zhejiangyanhe.wholesale.chinaqualitycrafts.com/iz5eed42b-stair-climbing-folding-shopping-trolley-images.html They make lugging heavy things up or down stairs a bit easier, and they're normally not toooo expensive.

    • Crusty...The AVO overload protection was the best I have seen in a meter, physical disconnection of the movement. I never had any of the Sinclair test equipment but remember the adverts for it in Practical electronics and the like. I have a great respect for Sir Clive, he did a good job of bringing technology to the masses at a reasonable price. I had Sinclair ZX81 and Spectrum computers, also great little things for their time.

    • Max...I have seen on TV a couple of times a documentary about Dean Kamen with Isabella Rossellini...it had in it most of the things you mention...there's a teaser here https://www.youtube.com/watch?v=w2Vmmo47ucU Is that the same one you saw? Dean Kamen is indeed a smart cookie....so many inventions across a range of technologies.

    • Good practical article as always Aubrey, thanks. Talking of ancient chips, the ICM7216 frequency counter (10 MHz, 28 Pins) used display and switch muxing. I remember on the early LED digital watches (remember them?) that if you moved your arm fast in the dark you would see the digits in different places due to the multiplexing. I wait for part 2 with bated breath!

    • Hi again Aubrey...I looked up the Fluke 8060A and it looks like the little brother to my 8050A, but it does Hz and has a continuity buzzer as well...nice. I take your point about the range change when measuring around 20mA, it can be annoying.

    • @Antedeluvian, I thought you'd remember Hamrad. Lovely shop if you were an electronics nut. There was another one in Durban, A1 Radio I seem to remember, which was like one huge bargain bin. I still have a pair of VU meters I got there, in their original packing (I got 2 and only used 1.....

    • @Antedeluvian...which all goes to show that you can't please all the people all the time! Points taken though, and I have advised Art Kay (one of the authors) that the blog is up, so he may take note of your comments for a future edition.

    • Aubrey... I found a beautiful mercury tilt switch the other day on some old stuff but did not have the right tools to remove it... must remember to. I heard somewhere that Zimbabwe's asbestos is particularly long-fibre compared to most of the world, which makes it much less dangerous. Not sure if that is true?

    • I had the "not enough solder" problem with relays on a washing machine control board, a year and a week after I purchased it with a 1-year guarantee. It was potted, so had to get a new board ($186). A week later I saw a recall notice for the problem. I did manage to get a refund from the company (LG). If someone could invent a machine to solder relays, power connectors, etc properly I think he'd make a fortune.

    • Aubrey...do you remember the old Mercury-wetted contact relays beloved of teleprinter comms designers? They had a bead of mercury on the contacts which kept the contact closed during bounce - once the contact had made, the mercury kept the circuit closed as long as the contacts did not get too far apart. You had to ensure they were mounted a certain way, and you could shake them to re-wet the contacts. I guess these days, they would be politically incorrect... :-)

    • Nice coverage as always Aubrey. Years ago I had problems with under-specified connectors in some old terminals, they would overheat and oxidize and overheat some more, sometimes melting the connector body. Fortunately I could get spares for them, but it was always necessary to replace both the plug and socket parts when the connector had over-heated, otherwise I got that same problem again very soon down the track. But a far more widespread problem is that of not soldering connectors to PCBs, I have written about this before. Automatic soldering processes almost invariably do not put enough "meat" on the solder joint on the board, and in the case of a connector that gets a lot of use (power connectors being a favorite for this)they work loose and go high-resistance. Wherever possible I re-solder these joints by hand, and usually have no more problems.

    • Thanks Aubrey - a great series of articles. I was propted by your artilce to look up thermocouple connector colours - aaarrggh! Why can't the world standardise? I can't post images here (Grrrr) but here's a link: https://www.labfacility.com/cache/images/rsz/cache/filelibrary/258/library/fileLibrary/2012/3/Latest-Colour-Codes_600_0.jpg

    • Nice reference article Ken, thanks. Would it be worth using a lookup table to correct a bit more? I appreciate that this would work out more expensive, both cost wise and in terms of pins used, but an I2C sensor such as the DS18B20 will give 0.5 degree accuracy, if you're clever you can put a few of them on one I2C Bus. What do you think of them?

    • Max...love the pic (the Gene wilder one, though I'm also a Calvin & Hobbes fan). From Young Frankenstein I think? GREAT movie. We had it when I was on a remote island for a year and I must have watched it 10 or more times and still laughed.

    • Aubrey... I'm an old fart, so love BASIC, so I had a quick look at BBC BASIC. Looks nice, pretty versatile and cross platform support. But I'm intrigued as to why you use this instead of Visual Basic...simplicity (I'm a big fan of the KISS principle) or are there other reasons?

    • Aubrey.... thanks...unfortunately I can't delete this now you've corrected it, like one can on EET :-(( but it now looks even more professional :-))

    • Nice article Aubrey, everything looks very professional. However... "...the gold devices are the power resistors connected to the MOSFET emitter." MOSFETS have Emitters???

    • @Steve...."My clock...is now housed in a rather nice Ash jacket." You lie like a cheap clock :-) Your bit of wood in your video said it was Sycamore!

    • Steve... "working with individual LEDs, maybe I'll do this, I quite fancy trying to accurately drill all those holes lol." I had a friend who was into lathe work (metal, not wood though) and he once helped me drill a nice pattern of holes for a speaker in a front panel using a thing called a dividing head. It came out looking really good, precise spacings. Is that what you would use?

    • @Jussi...in an earlier life I worked for an electricity utility in Zimbabwe, and we had Power Line Carrier circuits to carry telephone traffic between our main centres. Analog multiplex equipment at a few hundred kilohertz. Now I still work for a power utility, in Australia. We use what's called Frequency Injection (FI) - very low rate data (think 1 Hz) with carrier of around 300 Hz, it sends about a 20-bit word and the codes can switch streetlights, hot water systems, etc, on and off. Power lines are not bad transmission lines - nicely spaced conductors, low resistance....

    • Love ya work Steve! Me and wood have never got along, but it is always a pleasure to watch a craftsman at work. One thing I don't like (and this is a criticism of Adafruit, not you) is that you can't get rings of intermediate size between the 24 and 60 element rings. I reckon it would make for a much better look.

    • Max I can't do this in C (I could do it with an LM3915 :-) but a very nice effect is to combine the peak and instantaneous readings of a level in the same bar. I could offer you a rough algorithm to do this: - means start of instruction line, # is rem line GT = Greater than, LT = Less than (Embedded won't display these) - sample level initially - display level, also store as peaklevel, set another variable (peaktime)=1 Loop: on every subsequent sample: - sample level - display level # rem if level is greater than previous peak, reset peak - if level GT peaklevel then peaklevel=level, set peaktime =1 # rem if level is less than previous peak, display it separately and increment time counter - else if peaktime LT 100 display peak level as dot in different color, peaktime = peaktime+1 # Rem but if peak is too old, don't display it but get a new peak - else peaklevel = level, peaktime = 1 - loop back to loop heading unless exit condition exists What this will do is keep a peak level and display it as a separate dot (in a different color) above the instantaneous level. It will keep doing this for 100 loops or until a new peak is found. You'd want to keep your peaks displayed for 1/2 to 1 second for best effect. Here's a video of a similar effect, here they decrease the peak level after a time instead of just getting a new one, but you see the effect. https://www.youtube.com/watch?v=lRInk7jwQmk

    • It's easy enough to do lockouts even with a uC based system. Simply put good old relays on the outputs (or use contacts on existing relays - which would probably be there to drive 110/240V lamps) such that the supply for one direction's green causes the other direction's green supply to be cut. more complicated on big intersections with filters, but surely worth it to prevent accidents?

    • Also in Gweru is Boggies Clock. This was erected in 1928 by a Mrs Jean Boggie in remembrance of her late husband. There is also a local newspaper called the Gweru times. A local joke has it that The Gweru Times may be observed on the four unsychronised faces of Boggies Clock... @$%&^$#...I can't paste photos here. but https://www.flickr.com/photos/windlass21/5715663346

    • Flashing orange was certainly the norm in Zimbabwe (that's if the lights go wrong when the electricity is actually on... :-) and I think in Australia. I did a PLC (Programmable Logic Controller) course recently and one thing we had to do was design a PLC controller for traffic lights. It's easy enough to make the greens exclusive. Blame the computer. "To err is human, to really stuff things up takes a computer." :-)

    • "The power of accurate observation is commonly called cynicism by those who have not got it." George Bernard Shaw So you're telling me I am turning into an accurate observer? :-)

    • Max: "And can you conceive how the lights I saw yesterday evening had managed to fail with both directions green?" Easy answer: someone did not do their job properly. Accounts for probably 95% of cases like this?

    • Thanks for that Max.... I remember reading your Ipad Apps Blog but I will revisit it as a very nice guy gave me an Ipad recently and Notes Plus sounds like just what I need - I am as bad as most of your other commenters at keeping good notes on my projects. I usually end up retracing the schematic from the prototype to document it properly. With an IPad and a stylus you could do fairly detailed diagrams I think.

    • Aubrey... Nice article again. Your first pic (with the "globes") made me do a double take. 13 years ago when I started in my present job I was put in charge of UPS maintenance - think lots of small (up to 1KVA) UPSs. I had a Tandy 5-digit counter so I made a load almost identical to yours with 6 x 100W globes, and a bit of electronics to derive 6 second pulses from the 50 Hz mains, driving the counter which then read in 1/10 minutes. You connected the UPS, switched as many 100W loads in as you wanted, then cut the power and reset the counter (I never got around to making this automatic :-) When the UPS ran out of battery, the counter recorded the run time of the UPS until you reset it again. Prior to that I always used to go off somewhere and miss the cut-out. It's still in our workshop and I used it jsut yesterday. A lamp / globe is a good load for UPSs as it has considerable inrush current, just like a PC. Yesterday I was testing a 600W / 1000 VA UPS but I found I could only put 400W of load on it before tripping its overload alarm.

    • @Antedeluvian, Crusty.... There is an upcoming article in Elektor Magazine about driving PTZ (Pan, Tilt, Zoom) cameras. Usually they are driven by a separate RS-485 line, and that's what the article proposes, but there are numerous converters on the market which will combine the PTZ control, the power and the video signal onto one pair of wires. Of course using Power over Ethernet (PoE) you can do it all on one 4-pair STP cable....

    • Max... "More recently, I decided to include a figurine of a tall, dark, dashing man sporting a Hawaiian shirt, with an H.G. Wells-type time machine sitting off to one side of the cave." I love that idea! But I wonder who the tall dark dashing hawaiian shirted guy is modelled on?

    • Max... Model railway electronics is a subject unto itself these days - there are standards and protocols for control of the trains and everything else. If you don't know much about these (I certainly don't) you'd be wise to enlist an expert. There is one in our midst - possibly Zeeglen? BTW, did your wife sell the house to that couple?

    • Aubrey...fine article. I have used the Maxim DS18B20 temperature sensors while playing with PICAXEs, but alas the Picaxe will not let you use it in true one-wire mode. But it's certainly a nice way of doing things. You can remote a temp sensor from your electronics and still get 0.5 degree accuracy without worrying about the length of your wires. In the good old days we'd have called this magic....

    • Nice work Aubrey! 50mA average forward current ain't bad. There is some (fairly skimpy) data on some of the OA types here http://pdf1.alldatasheet.com/datasheet-pdf/view/166123/ETC1/OA91.html But really, with meters, you are interested in limiting the voltage across the movement, so a well selected schottky diode would be just as good if not better. I have found a very wide variety of Vf in schottkys, from just under 0.2V to over 0.4V. The lower the better for meter protection obviously, as long as it does not encroach on the Vfsd of the meter. Off-topic, but have you noticed how AllDatasheet.com (and I think some others) will now only give you datasheets in HTML format? Annoying, though they still let you save the datasheet in .htm format. I'm not sure why they did this, any ideas?

    • @Antedeluvian... "Can you still get germanium diodes...?" I really don't know! I have tons of them around, removed from old computer boards many years ago. Maybe I should sell them on EBay as "meter protection diodes"... I'd guess someone would still make them in one form or another. These days Schottky diodes are just as good for these purposes, though they probably start conducting at a slightly higher voltage. Yes, the old OA91's were not too robust. But as long as you could limit the current they would have to take to a couple of mA, they'd do the job here. If you want to rectify more than a crystal set output, forget it. But even the humble 1N4148 can take an average forward currrent of 200mA. An OA91 could take that for about a millisecond, during which it would convert the current into light.....

    • You got it wrong Max. You should have said "The really scary thing to me is the lack of any form of knowledge most politicians seem to have..." Were I on EET I would have used strikethrough on the missing words...but thie is E.C....

    • @Max...be careful about that...with the benefit of hindsight Duane might say "How could I have done that??" and delete something that would vitally benefit a newbie just starting out who would otherwise make the same mistake.....

    • Duane... "I picked up FPGAs a few years ago..." And as I remember did a very fine series of articles on your endeavours. Max, could Duane's articles be reposted somewhere on Embedded.com - they would be as useful now as then I think?

    • Thanks Crusty. Electrostatic meters - alas no, the nearest I have ever seen to one was the gold leaf electrometer in physics at school. I wanted to keep to practical topics and the article was getting out of hand length-wise. You should write one though!!

    • Awesome little board Max and I can see why it makes you do your happy dance. Jamie obviously knows his Audio. I was also interested to look at the other boards you mentioned. I have been thinking about building myself a new audio system, but I'd like it to be all-singing, all dancing, ie do everything, like - play CDs (audio or MP3) - Play mp3 or other audio files from a USB stick or SD card - act as a bluetooth speaker system for Ipods/Ipads/etc - where possible, display what audio is being played (artist / title etc) I've been looking around and have found odd devices that will let me do one of the functions above in varying degrees, but nothing that will do all of them. Do any readers have any ideas? The most likely way to do all this that I know is to have a mini-PC motherboard inside the system, and maybe a small (4-5 inch)VGA screen (touch screen preferably) on the front. I still have doubts as to whether even that could pick up bluetooth from another device, though. Anyone got any other better ideas? Thanks.

    • The French company Metrix used to make very good looking analogue meters, also very colourful. But I have never seen an analogue multimeter with a continuity Beeper!

    • Ken, in your fig 3, I have used an LED in place of the Zener + diode combination. seems to work fine for battery charging and the like, not sure how the temp coefficients of LEDs and Transistor BE's would match for precision work though?

    • @Rcurl thanks....I've mostly seen "Mirror scale" used for the mirrored scale ones, and "Mirror galvanometer" where the movement drives a mirror, but Scanlab calls them Galvanometer Scanners. So take your pick! http://www.scanlab.de/en/-/products/dynAXIS#21029 I'd love to see a pic of your 80-year old one. 2uA is pretty sensitive, that's impressive, best i've seen (and heard of) prior to this was 10uA.

    • @Antedeluvian thanks... you are right, that was a serious omission. Your technique actually can work if your meter has some particles in the movement as described. I gather it also works with barometers :-)

    • @Crusty thanks....wait till you see (later in the article - they've split it into 3 parts) what current a moving iron voltmeter takes - it is frightening. I remember Weston cells and slide pots (but only just - we are seriously dating ourselves here). Calibrators these days are so much easier...

    • @Crusty...only just looked at this....great article, I also have saved it for future reference.

    • Very nice and complete coverage of this subject Max. And it confirms my suspicion that if you wanted to rearrange your Neopixel strips in your BADASS display from 16 x 16 strips to 1 x 256 strip, the interconnects between each strip would only have to carry the data between 16-long strips, they would not "add up"as the data is regenerated by each neopixel. So as long as the interconnects did not interfere with each other, you'd be laughing. At 800 KHZ you should not get much interference. You could also put a resistor from each interconnect to ground - maybe 10K or so - load the interconnects a bit to minnimise any interference. I don't know if the output/input impedance of the neopixels are listed anywhere?

    • Nice tutorial on this topic Colin. I cut my teeth on Async protocols, then on Sync protocols using ASCII characters to delimit messages. The first time I was in a course on Bit Oriented Protocols and the instructor asked "What if we want to send ANY sequence of bits?" learning about Bit Stuffing was a revelation.

    • Bear in mind that if the neopixels regenerate the signal (they seem to ahve shif registers in them) you only need to wory about getting from the top of one string to the bottom of the next one....

    • Max...I'm not familiar with connecting NeoPixel strips, but surely it is possible to take a wire from the output at the top of the first NeoPixel strip to the input at the bottom of the 2nd strip to create your one long strip without taking them off? As I recall from previous posts, they work at about 400 KHz data rate, so the extra foot of wire is not likely to cause problems at that frequency? All you'd need is some more white wire.... This would save your "algorithmic messing around" if you invert alternate strips....?

    • Well, once you depart from pure spectrum analyzer type display, the world's your oyster. You could have it doing a weather station display, with the sun with rays emanating from it, or your raindrops as above, or clouds scudding across...you've got enough pixels for a few digits of 5x7 numbers for the temperatures....etc..... Something for it to do when there's no music on?

    • Nice work Max - the back looks as good as the front! Your last pic gave me an idea for another "mode". Use oranges, reds and yellows and simulate a fire. With 15.5 A from the power supply, it would probably provide a bit of heat as well!

    • There was a TV program a while ago on Dean Kamen with Isabella Rossellini, he went through with her some of his major inventions. Put the two names into google or you tube and you can get snipetts, I don't think the whole thing is there, unfortunately. Quite a guy, and quite a catch for ESC Boston.

    • Budgie = budgerigar is a small Australian Parrot. With typical cheeky Australian humour, tight male bathing trunks are referred to as "Budgie Smugglers...

    • @Max - it's still more elegant to link some text to a hyperlink....and I put jsut instead of just and I can't correct it....and when I click on your comment in the list it only takes me to the beginning of the blog, not to the comment, and I still can't bold or italic or strikethru, and I can't post pics...do you want me to go on???

    • Talking of Terry Pratchett, I have only just put two and two together. (Yeah, don't tell me, I'm a bit slow...) I saw his documentary Choosing to Die some time ago - it was very good and he came across as a first-class guy. I've only jsut realised that this is the same Terry Pratchett who wrote the Discworld books. Which I have not read. Which now seems like a serious omission.... I can't insert links here (Max - you listening?) so here's a cut & paste link to the wikipedia article http://en.wikipedia.org/wiki/Terry_Pratchett:_Choosing_to_Die You can also find bits of it on you tube I think.

    • @Crusty...so there is not even space to lie down beside the track? Scary stuff. Anyway, glad you are still with us to regale us with these tales from the tunnels... :-)

    • Aubrey...the worst thing that happened to me there was to have a jealous bull fur seal chase me (I think he thought I was trying to steal one of his harem). It was on a beach of large boulders and I had wellies on (Marion is full of bogs). I slipped and fell and remember seeing him almost on top of me. Bull fur seals are the size of a very large dog and have a good set of inch-long teeth, so this was a bit alarming. He took a snap at my leg and (I think) realised I was not another seal, and turned and went back to his part of beach. My wellie had a 2-inch round hole in it. My sock had a hole of about half an inch in it. And I didn't have a scratch. I was SOOO lucky. Another funny African story. As a radio tech in the Rhodesian police, I went up to a hilltop repeater to do some maintenance. (Repeaters were manual in those days!) The guys there had been having problems with a baboon stealing their food. One of the guys killed a snake and had an idea. He tied the snake to an orange with a couple of metres of fishing line, and left the orange out in view. The baboon came and grabbed the orange and made off, only to realise that he was being chased by a snake. Unwilling to drop the orange, he just loped off a bit faster...but the snake was still chasing him. The last they saw of the baboon was him charging off down the hill, and they had no further problems :-)

    • Max, have you thought about syncing the LEDs to the seconds? I see you have 16, so that implies a change every (just under) 4 seconds. You could maybe change the color or add a color every change time, or light one more led every change, or have all the leds flash every second and slowly change the inbetween (background) color through the minute...you could easily get bogged down with this....

    • @Antedeluvian... "Lightning in Southern Africa is always a problem." Don't I know it. When I was renting terminals to travel agents (think RS232 up to 30 meters long) I was plagued by lightning blowing the 1488/89 RS232 driver chips. It was not then economically viable to install surge protection on every line. I did make a test device to test the chips and locate which one was faulty (there were 3 in each terminal and 24 in the controller). I always socketed them on replacing them, which guaranteed that the same one did not blow next time (an application of Murphy's law for you, Max :-)

    • @Max... "...I'll just sit quietly in the background writing down your tales of derring-do." I think Aubrey's will top mine - both technically and for exotic dangers....

    • It's always a delight to see a tool like this which is so well designed, obviously by someone who has "been there and done that" and developed something to make life easier. I want to come to one of the ESCs this year and had been thinking about Boston, but it will probably be SV. Max, can't you give Guido a gig at all three??

    • Aubrey...Knowing the capriciosity (yes, it's a word, I just made it up) of African monarchs and dictators, your course of action was very prudent :-) My story is of lesser consequence but equally alarming at the time. As a radio tech in the Rhodesian police during the war in the '70s, I was tasked with installing a radio in the rather rural home of the Chief Justice, for use should he be attacked and wish to report this fact to the local police station. A storm was passing as we set up - a 40 MHz 1/4 wave ground plane antenna on a 40 foot pole, and leadin cable to the radio which was inside with a battery/charger for power. I was fairly new and I had once got a good Zap off an antenna when a storm was brewing, but had been told that once the storm has passed the chances of discharge on the antenna were small. And we also installed a knife switch to ground the antenna if necessary. As it had been stormy, I grounded the antenna (without any sparks) before plugging it in to the radio, by which time the storm had mostly passed. I tested with the police station successfully and was about to re-ground the antenna when there was a tremendous flash and clap of thunder. The radio let a small amount of magic smoke out. Fairly embarrassing. Never believe what your workmates tell you....

    • Max....very tasty. But what about security? If you use these to automate your house, for example, would anyone with the Simblee app be able to hack your house? I'm sure (well I hope) they've thought of this but how does it work?

    • Max, I share you pain and in fact I am in awe of you because you manage to actually finish (slaps self on wrist for using split infinitive) some of your projects. I have so many things on the go, articles for EET and others, thinks to fix, ideas for projects (so few of which get past the idea stage, it's not funny). I need to win the lotto and retire, this silly work stuff takes too much time. And even if I did there would not be enough hours in the day. When I see guys saying "What am I going to do when I retire?" I want to slap them.

    • Isn't a clock (well one with an escapement or a quartz timebase) a digital system with an analog display? When I was a kid we had one in the lounge with a noisy synchronous motor in it which I guess was truly analog....

    • Max...can I suggest you try raising your beer to your lips with your right hand instead? I had a teacher at school who was ambidextrous. He'd be writing something on the board, pause for thought, then carry on writing with the other hand. I'm ambidextrous too. I'm no use with either hand....

    • I am signed in to TOL and it tells me "Welcome David" at the top. Yet if I try to download any articles I am asked to provide a whole bunch of info that you already have. Sorry, too much like hard work. I'll look elsewhere.

    • Jack...can you comment on putting a large capacitor in parallel with the coin cell to give a bit more "oomph" during short periods of power use in systems that are effectively off for a large percentage of the time?

    • Nice ideas - a sort of universal do-anything panel meter. Have you got any reference designs available?

    • If the company had any sense they'd have offered him a really, REALLY good deal on an "Upgrade" to a newer model - which would probably have been cheaper than fixing it, and they would have kept their customer, in fact if they'd done it right they'd have had a very happy customer, which is the best advert any company can have.

    • Nice quote....but that's exactly why it is so difficult. Communicating a passion for something is not always easy. It very much comes down to the teachers...look at the recent Led Challenge on Igen if you want some examples. Not being sexist here, but in Australia there is a shorage of male teachers and this may have something to do with it - fewer females are likely to push STEM? In my case my dad did everything he could to encourage my interest in electronics, although he was completely non-technical, and I'm glad he did. (probably he just wanted someone who could fix stuff... ;-)

    • It's not too new, this, years ago it was common for some airline terminal systems to network with RS 485 like this. It's a really good cheap way of connecting lots of things together. Cheap chips, cheap cable and reasonable speed if you don't want to shift MB of data around. If you're doing this though, socket your RS 485 driver chips, they can blow fairly easily, especially if there is lightning around.

    • If nomophobia is the fear of being WITHOUT a cellphone, what is the fear of being WITH one?? I hate the damn things, though I do realise they are a necessary evil.

    • I guess implantable stuff would have these problems, but possibly a device that you wear like a pair of glasses, with a camera that you can focus on anything you want (better still, autofocus), and zoom in on things would be quite cool. Like virtual reality displays, only customisable for your eye prescription. Voice-activated, naturally... "Zoom in, eyes!". That would make reading those SMD part numbers a doddle.....

    • I have always been fairly near-sighted and have worn glasses since I was 7. People sometimes ask me why I don't get Laser eye surgery. My answer is that with the top of my (bifocal, I can't stand varifocals) glasses, I can see from infinity to arms length. With the bifocal bits I can manage from there to 8 inches or so. And with my glasses off I can get down to about 4 inches. Why would I change that? Trouble is, as I get older, the ranges don't overlap so well, and I have a cataract coming that is eventually going to have to be sorted out. I increaingly need a magnifier to read even through-hole components. so one of your devices will eventually be pretty welcome. I don't see how you could compensate for cataracts, though, they're a source of optical "noise" that you'd have to bypass somehow?

    • Read "Can" for some of that Duane, it's already happening. Here in Australia they have "Ripple relays" with coded pulses of tones sent over the electricity wires which can switch your hot water heater off for "load shedding" if needed. Even back in Zimbabwe they used to do this, though on a cruder level. We'll jsut see more of it coming in I reckon.

    • I was going to say it reminded me of my first computer - a Sinclair ZX81 - Z80 based, membrane keyboard, 1K of user RAM I think, BASIC interpreter, and a monochrome TV output. I later graduated to a Sinclair Spectrum - colour TV output and the possibility to attach a better keyboard, and also a 16K plug-in RAM pack and printer interface, which had to be secured well to prevent the dreaded "Wobbles" which would hang the machine. Laughably primitive these days, but I learned BASIC and even machine language programming on them. I'm sure today's kids will eat these Raspberry Pi's for breakfast - and good luck to them, they'll learn more with these than from the ubiquitous computer games.

    • Frank, the book from whihc this was taken is as you guessed a collection of LT App Notes. There was considerable discussion of it at http://www.eetimes.com/electronics-news/4219438/Analog-guru-legacy-text-book

    • Try getting it direct from TI: http://www.ti.com/lit/sg/sszc003c/sszc003c.pdf

    • I just downloaded it, worked fine.

    • As CDHManning remarked, there was not a lot of Heathkit stuff around in South Africa, and even less in Zimbabwe where I grew up. But someone sold me a Heathkit Oscilloscope when I was about 19, and it served me well. It eventually died when the main power transformer cooked itself, probably due to a power surge or lightning, silly me for not having a CVT and surge arrestor. I'm sure I would find it totally inadequate now, but i'm pleased to hear they're starting up again. Maybe a PC-based scope add-on is on the cards?

    • Interesting posts here. I have been to a few Labview presentations and find it fascinating. I have even considered getting the basic Labview certification, though it's not that cheap. Can anyone in the field tell me how valuable Labview certification is in the job market? Is it a good skill to have on your resume, or are there better things to get? Thanks...

    • Hey, guys, don't be lazy...one click (on the PDF icon at the top (or where it says Click to Download) and you have an almost fullscreen copy of the paper without that many ads. Save the PDF and reopen it and you have one with NO ads. Even with my slow (256K) broadband it doesn't take toooo long. As Zeeglen says, the advertising enables you to get this stuff free. Plus the "Navigate to Related Information" bar often leads to more gems. Just be grateful EETimes gives you such easy access to this info, all in one place. When I started 30+ years ago, you depended on magazines once a month and Databooks which were expensive and difficult to get. EETimes is a veritable paradise by comparison.

    • A good topic for legislators the world over would be to mandate that electronics must be more repairable. See the post... http://www.eetimes.com/electronics-blogs/engineering-investigations-blog/4213916/The-case-of-the-flat-panel-TV-scream ...for a good story about how easily people throw away perfectly repairable electronics these days. And this was by no means a difficult repair! Maybe some legislation about making sure that spare parts are available for a minimum time (5 years??) or credits for recycling unwanted PCs and TVs (through charity shops?) or something?? It's criminal the amount of stuff that is just thrown away without anyone having even a basic look at it.

    • "At ISSCC, researchers from Europe will describe an 8-bit, 6 Hz device...." 6Hz?? Now that's fast!! Does anyone know if that should be KHz, MHz or GHz? My guess would be MHz, but who knows? "The organic processor is showing real promise though it is some distance from real utility..." Maybe it IS 6Hz.....

    • Well I'd give him more money for good content, but take it away for crappy sound...... Interesting stuff, I've never worked in a large-scale manufacturing environment but always wondered how they keep track of everything.

    • Think of it as a blessing. You will appear more productive because you don't waste time on these sites. All of these sites are like the rest of the internet - you can take the best parts and leave the rest. There's a lot of crap on the internet, but how useful is it when you need some info? And isn't EELife kind of the same, just oriented towards like minded engineers? I haven't yet been convinced of the benefits of any of the sites mentioned, but I do check out EETimes a couple of times a day usually.

    • Above, under "Other recent articles from TechCareers" at the end is a link to an article "How To Beat Age Discrimination In The Job Search". This link does not appear to work, the correct link is below http://www.techcareers.com/articles/how-to-beat-age-discrimination-in-the-job-search-3413-article.html Quite a good article, worth a read.

    • Anyone remember the pre-internet age when data was like gold dust? Towers International Transistor Selector (aka TITS) was my bible for years. I remember buying a couple of National Semi linear books in London in the early 80's and being soooo happy I now had datasheets on so many ICs. (I lived in Zimbabwe and there, if you were lucky, a distibutor might give you a photocopy if you asked really nicely). Now you can google just about any part number and get a full datasheet in seconds. Or from the manufacturer you can get lots more (for a year or two, anyway - dont ya hate the ones that stop giving data on older chips?) Or it gets thrust at you in places like this. Sure beats the good old days.....

    • My understanding is that you use the SSD for the OS, for fast booting and quick immediate access stuff, and the magnetic drive for higher capacity data storage. The SSDs are much faster than mag drives but not large capacity. Some friends of mine have tried this and they reckon it works for them. 60% is a pretty good improvement I would say? Anyone with more knowledge care to comment further?

    • In Arthur C Clarke's 3001 he referred to a device called the "Autochef" which produced food on demand, suitably nutritionally balanced for the user. Maybe the iGrill is just a step towards this. It's not too much of a stretch of imagination to envisage buying your meat with a sensor implanted in it (something like an RFID chip) and you just pop it in your (suitably enabled) oven and dial up how you want it done, and the oven will switch off and tell you when your rare beef roast is done just how you like it. (I'd go for that, I never get it as rare as I'd like... I should patent this....) And let's face it - they are putting microcontrollers in even the humble toothbrush these days. So is there anything which won't have one in eventually?

    • Well nearly. In a comment on something else some time ago, I described an electric fence unit I made for a friend...old valve radio transformer back to front, charged a cap to 100V on one half cycle and fired it thru a thyristor to a car ignition coil with the filament winding on the other half cycle. What has this to do with Frank Zappa? Well my friend's name was Frank, so we called it Frank's Zapper....

    • @Antiquus: thanks. I have been thinking a lot about how I would do this - not being a hot shot designer makes that a bit difficult. The ball I thought would be easy enough, an LC or gyrator circuit with active full wave rectifier. And for the horizontal motion, a triangle wave generator which can be reversed at any point. Easy enough. But then I watched the video again. And sometimes the "ball" goes high and slow, and sometimes low and fast just over the net. So depending how it is hit, not only the vertical velocity but the horizontal velocity changes. Bit of an advance on my AY3-8500!! I guess you could consider the hit as a vector and take the horizontal and vertical components (depending on the pot setting) and apply them accordingly. My conclusion: these guys certainly knew what they were doing!! Are the schematics available anywhere?? I love analogue stuff like this...

    • I remember putting together a game using the AY3-8500 from General Instruments in the late '70s. It was a project in Elektor and it was my first project with a "huge" 40-pin chip....but this is 20 years before that...amazing.... With digital it's all easy...but to get the ball AND the net AND the baseline all in analogue must have taken some doing at the time... presumably on a dual-trace scope (don't think they had 4-input scopes in those days??)

    • Txema: From the article: "Antenna absolute gain is defined as the ratio of the radiation intensity in a given direction to the radiation intensity that would be obtained if the power accepted by the antenna were radiated evenly to all directions of surrounding space (i.e. isotropically)" Makes sense to me. Also it's important to distinguish between gain relative to a dipole or relative to a (hypothetical) isotropic antenna Hence the dBi used in the diagram on Page 4 (of the PDF). Some antennas (eg the quoted "monopoles with parasitic elements") may radiate in a pattern that is equally strong in all HORIZONTAL directions. So you might get a radiation pattern that is like a much flatter doughnut than that shown on Page 3 (again of the PDF). Jouni - could you say that antenna efficiency is the ratio of the actual radiated power in the direction of interest (usually that of max. radiation) divided by the theoretical predicted radiated power in that direction? and what sort of figures would you find in practice? Great article - thanks! (and RF ed - thanks for the PDF link)

    • There IS a fundamentals of FPGA here: http://www.eetimes.com/electrical-engineers/education-training/courses/4000134/Fundamentals-of-FPGAs Pretty good too, would like a follow on to that one too though...Max???

    • "Regretting your knowledge of Latin, History and Art is pointless. There is nothing stopping you studying this stuff **now** - either formally or informally." I agree totally....and have not stopped learning at all (just getting slower at it ;-) But when you have a job to hold down, lawns to mow, cars to wash, wife to take shopping...etc....it does not leave much time to cram in ALL the things you want to do. You only get to do some of them. And you have to prioritise. Roll on retirement for some me time.....

    • A compromise is needed here. Most kids have no idea what they want to do in life. So they need a good grounding in just about everything before they get chucked out into the hard cold world. So that incudes Math, and History, and English, and Geography, and lots more besides, until they're at LEAST 16. When I was that age, we had to specialise thereafter, in either "Arts" or "Science" subjects. I was always mad keen on electronics, so chose Math, Physics and Chemistry, and was just about bored to tears. I really wanted to do Math, English and French but I couldn't. University or college is where you should specialise, but before that I think you need to do as diverse a grounding as you can. I've always regretted my lack of knowledge in Latin, History, Art.... although it wouldn't have helped me directly in an electronics career. I recently tried to brush up my calculus....not easy when you're 53 and last did it at 17..... but at least I have some basis to build on.

    • Which is why the vast majority of the population will belive any statistics that are thrown at them without question. When you ask them, eg, "Seventy percent of WHAT?" you can usually flummox them completely.... My math is not that grteat, but I'm glad I have it.

    • If Greenpeace was (a) right and (b) above board, they would have some decent engineers and scientists on board. The fact that they don't makes me suspicious. Engineers are not easily fooled and thus won't lend any support to a suspect cause. Greenpeace have a lot of good objectives but they shoot themselves in the foot with bad science.

    • Credit card scams are already huge (anyone got a figure?) and the easier you make it for the customers, the easier it is for the crims usually. It is heartening that PayPal takes this so seriously though, they do a good job, you have to be pretty stupid to get your paypal account scammed. Bring back the death penalty for scammers, I reckon, does the human race really need these people???

    • Easy answer.....save it to disk and then open the PDF...no ads! (click on disk icon 2nd from left on top bar). I do agree that animated ads like this are a pain.

    • Hmmmm...so it's not as universal as I thought. Is there a lot of electric water heating in the States? In Aussie there is, though there is a push (via subsidies and incentives) to change to Solar and/or gas. Mine's gas so I can't get a solar subsidy. But it does make sense to use remote control of water heaters to reduce demand, and it works well as long as the switch-off is not so long that that water gets cold. Zimbabwe currently has major power problems so the hot water is turned off most of the time. (In fact the power is off a lot of the time...) One reason I am now in Australia.

    • "As a home owner I doubt I would allow any external control over my appliances". You probably already do, certainly in both the countries I have lived in (Zimbabwe and Australia) the utility can switch off your electric water heating remotely to reduce peak load, I'm sure this is pretty universal.

    • Possibly it was a "liberator". A friend of mine got "locked in syndrome" (see or read "The diving bell and the butterfly) and has one of these devices. His mind is all there, he just could not talk, and now he can with this device. It's a slow process, but it's heaps better than having to use a "translator" who reels through the alphabet and picks letters out when he winks. I think Stephen Hawking uses something similar as well. You're right, a very noble application of technology, but these things are not cheap....

    • You asked Am I a cynic or a realist? I can't always tell. "The power of accurate observation is commonly called cynicism by those who have not got it." – George Bernard Shaw, author (1856-1950) So you're both!!

    • Surely the benefit of smart meters is to the utility, who can read them without sending a (costly) employee round to read the meter? With modern networking technology it should be possible (in fact mandatory) for the utility smart grid network to be separate from the corporate network and internet, but hackers have a habit of finding their way around that....

    • Because the Indian and Chinese ones wouldn't, and the bean counters would rub their hands with glee, because they'd have yet another excuse for offshoring. Until governments start looking after their own people nothings gonna change.

    • Great article. Would it be too much to ask that we come up with a universal standard of how to transmit GPS location automatically from phones equipped with it whenever a 000 / 112 call is made? It would (a) help emergency services and (b) help trace nuisance callers. With the intelligence in phones these days it should not be difficult. The hard part is getting mankind to agree on a standard for it without too much bickering......

    • Most of the answers to your questions are within the article: "The Global Positioning System is mainly funded and controlled by the U.S Department of Defense (DOD)" "The Space Segment of the Global Positioning System consists of 27 Earth-orbiting GPS satellites. There are 24 operational and 3 extra (in case one fails) satellites.." As we are working in a 3-d environment, 3 satellites will give you a 2-dimensional location on the earth's surface, and 4 satellites will give you a 3-dimentional location (ie position plus height). I never was much good at 3-d trig but I can see how this works. Think of disks from each satellite (like saturn's rings) intersecting at your position on the earth's surface. 2 satellites will give you a line where you might be, 3 will give you a point and 4 will give you height as well.

    • If the world was run by engineers, instead of the dickhead politicians, managers and bean counters that end up doing it, the world might work properly. But how many engineers have ever ventured into politics. And yet engineers are such solution oriented people that they would make it work. They just don't have the politicians gift for self-promotion I think. "How many teenagers ever stop to think about the design efforts poured into that iPod or Wii?" Not many. 99% are quite happy to use technology that, for them, is indistinguishable from magic. When I was a kid it was possible to learn how everything in a car, or a transistor radio, worked. These days it is well nigh impossible.

    • I have to carry a mobile for work, but after hours I only answer it if I know it is important. I leave it at home when I walk the dog. I hate the damn thing most of the time. It IS useful if you have to call roadside assistance or suchlike, but like the farmer that's for MY convenience. Max the magnificent posted a blog recently ref his new all-singing, all-dancing mobile phone. He was certainly converted - Max can you point us to it, I couldn't find it....

    • Well said Vince. Australia where I live has a program that subsidises roof top solar PV installations - it has been so successful that the government is probably going to scale it back as they've overspent. I think they have got to 50 MW so far. It also applies to wind generation. It's certainly one facet of an energy solution - but both solar and wind being weather dependent, energy storage technology needs to improve as well to fill in the gaps.

    • Begs the question - do we really NEED all this modern technology? I often reckon we were happier - and the human race was better - when life was a bit simpler. I appreciate that this is a bit of a luddite-like attitude for someone who works in technology fields, but I really think a bit of social engineering would do more for mankind than all the technical engineering feats we keep performing. For all the advancement in technology, we seem to find more and more gruesome ways of killing each other and stuffing each other's lives up, not to mention what we do to animals. For a bit of extrapolating from a far better mind than mine, see Arthur C Clarke's "3001" - the last in the 2001 series. Some pointed comments on the current social status of mankind there. I'm sure this will incite some responses, but what do the rest of you guys think?

    • Not sure if you get to read this Clive, seeing as it's fairly old now, but thanks for this and for Logic 101, while neither subject was new to me, both taught me things I didn't know. (whether this old dog CAN learn new tricks is open to question....)

    • Reminds me of my first computer: a Sinclair Spectrum using a Z-80, on the back connector of which you could plug a 32K (yes K) memory pack. You know something else? I don't think I ever managed to use all the 32K.....

    • Simon Go for your wooden stand. In the trade it's called "Proof of concept" - it shows that your idea can work, even if it's not ideal. It's better to do that and find out its a dud (though I don't think it would be in this case) than to pour heaps of money into it and THEN find out it's a dud. Another thing. If you know your idea is good, take out a patent on it. Otherwise, some other smart alec will steal it.

    • Nice little course, I gained a lot of knowledge on LDO use. One error I spotted - slides 15/16 are on regs with MOS pass elements but the diagrams show bipolar pass transistors.