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About dannyboy

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  1. That ULN2003 package looks convenient - am I right to think it'd be possible to power the entire LED strip through it rather than through the MOSFETs? That seems weird... what about heat dissipation? I guess my power requirements aren't very high (600mA at 12V makes 7W for the whole LED strip). Thanks everyone for spending time on me - I'm slowly finding my way through practical electronics! I come from code-land where everything is just high or low .
  2. Thanks, everyone! @@RobG and @@veryalive, I'd show my connections if I had more than a crappy phone camera which really does not photograph breadboards well. Believe me, I've tried. But I've been over the schematic many times since I discovered the failure, and I'm as certain as I can be that the connections are the right way around. The sources are connected to ground, and the drains to 12V via the LED strip. @@spirilis Thanks for pointing that out! I'd been reading that as needing 2-4V in any condition... silly me. I'm giving it 12V from a wall wart, and according to the Adafruit tut
  3. I've been playing around with an analogue LED strip - basically following this tutorial, but using a LaunchPad instead of an Arduino. I'm using STP16NF06 power MOSFETs rated for 16A/60V, which should be fine (the strip should draw no more than .8A at 12V for each colour). However, I've managed to induce failures into two of four of them - they allow drain-source current when the gate is held low, so two of my light channels never turn off. I'm not sure how I've managed to cause that failure, since I'm playing well below their rating. I hadn't been doing anything too extreme with the microc
  4. I've been playing around with Atom for a while - it's a Haskell DSL that generates C code that should run in deterministic time/space. I've been writing a library of MSP430-related definitions for it. Simple example. I've also been tempted to see if it's possible to get Nimrod compiled to C and working on a micro. It's a nice language and quite close to C.
  5. Thanks heaps everyone, using those tri-state buffers is a great idea. And I can get them as DIPs...
  6. I'd like to find an IC that will multiplex two 8-bit (i.e. 8-wire) signals, selecting one as output (on 8 wires). Does such an item exist? I'm not sure whether I'm searching for the right thing, but all I've been able to find is this TI 'LAN switch' which appears to do what I'm after, but doesn't seem to be breadboard-able. I could of course recreate the logic myself, using ICs with multiple 1-bit 2-to-1 multiplexers, but the wiring would be much less fun.
  7. I have wanted someone to make one of these for ages! Fantastic job. I imagined it having a bit less deviation (i.e., each tick being maybe a tenth to a fifth of a second off) but this is just great.
  8. Hmm, so IAR is having the same difficulty. I'll have a go reinstalling the drivers.
  9. This is a fresh install of Windows 7 64 bit, actually. I've installed the MSP drivers, and when I plug in the LaunchPad with a 2231 in the socket, I can find a 'MSP-FET430UIF' in the Devices and Printers menu. Energia only lists COM1 when the board is unplugged, but lists COM1 and COM3 when it is plugged in. I select COM3, upload one of the example sketches, and get: Binary sketch size: 547 bytes (of a 2,048 byte maximum) tilib: MSP430_OpenDevice: Could not find device (or device not supported) (error = 4) tilib: device initialization failed This is with 0101E0009. Where should I go
  10. Yes, leveraging existing tools should be a priority. that makes a lot of sense. Unfortunately I have found few other languages for specifying circuits, other than netlists or some package-specific formats like LTSpice's text-based file format. VHDL is important, but has different design goals. I will definitely have a look for more! CircuitLab seems to be the closest to what I want to do in terms of environment, sharing and so on, though they have an entirely visual editor and slightly less convenience (need to log in to create).
  11. The idea with 'via' is you can connect any number of routes to it. A route can just be a single component name X (which is shorthand for X.in>out), or you can specify the full route. So to add the transistor in the middle: V.plus -> V.minus via (R then Q.base>emitter then C) || L I guess having a '+' with regular precedence and using parentheses wouldn't be too bad. It makes it more understandable - replace 'then' with '+' if you're in a hurry :-P. That's the plan! Well, not C++ - the idea is to provide an in-browser editor and environment for other tools, again, something
  12. I guess it's easiest to show you by example: V.plus -> V.minus via (R then C) || L then Q.base > emitter The indentation is just for formatting, the language itself is insensitive to it. I'm also experimenting with briefer syntax options using more maths operators: V.plus -> V.minus via R & C || L then Q.base>emitter Notice that there are three operators with different precedences - the & (series) is applied first, then the || (parallel), then the 'then' (series again). Not sure if that would be too confusing. Using '+' instead of '&' might be a good idea
  13. Sorry, I didn't really get into detail about the language syntax in my post. I can clear that up - the 'via' keyword used for the resistor isn't vague at all when you know how it works. Via will create a route through a component in an automatic direction 'in' to 'out'. So I could equivalently write V1.plus -> R1.in V1.minus -> R1.out But using 'via' makes it clearer that the two ports are connected across the resistor, and it's more concise (Maybe 'across' would be a better keyword, but I thought 'via' gave a sense of the current flow... though of course, you could connect it backwar
  14. This is something I've been thinking about for a while. Circuit exchange, IMO, seems a bit broken. At least, this is my perspective coming through EE education (still in uni) and seeing people sharing Eagle files, hand-drawn schematics, etc. Sharing Eagle files is probably a good idea when you get to more complex circuits, and want to start specifying layout and more details, but for simple circuits, especially those you encounter in classes, images are just not a great way to go. I could talk about that a bit more, or I could tell you what I'm up to. I've started to specify a plaintext la
  15. Just wondering whether anybody has used eispice before. It's a Python library that implements circuit simulation. I've been looking around for SPICE programs recently for an electrical engineering assignment which I'd really like to apply some computer science to - namely, using a genetic algorithm to evolve resistor values that give good biasing. Using one with a Python frontend would be perfect, since the algorithm can be implemented in Python. I guess I just want to get a feel for whether eispice has a reputation - and of course, whether there are any other alternatives I should be
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