Relay switching using microcontroller

Today’s post is unfortunately going to be more of a tease than a practical layout.

I’ve been experimenting with programming micro controllers the last few days (AVRs to be specific) and I thought a good starting project would be to try operating a latching relay switching circuit with this instead of the CD4069. And hopefully the result will have a smaller dimension too.


Pretty basic stuff, I know, and I probably forgot something too, but I have breadboarded this and verified that the circuit and controller works.


I have yet to verify the actual vero layout though, but will probably do so pretty soon.

Now, I wish I could share this with you all, but even if I put up the AVR binary so you could download it there’s still the issue of having to program it onto the chip. I’m open to suggestions. If there’s any interest, let me know.

Update (01.04.2013): Works great 🙂

Update (11.10.2013): I know I promised this a long time ago, but better late than never. Here is the source code for the ATTiny85 micro controller used in this vero layout.


Now, this is meant for DIY-use only, no profiting! I’m not going to explain how you compile this and tank the micro, that’s totally outside the scope here. If there’s enough interest I might consider prep’ing some micro’s and mailing them out at cost. We’ll see.

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20 thoughts on “Relay switching using microcontroller

  1. I don’t think that relay will work, but possibly if you find the double winding variant. The switch is momentary, yes.

  2. I’ll consider posting the source for all, but first I have to find it (and possibly make it a bit more presentable).

  3. I would appreciate it if you could send it to me as well. Thanks for posting this!

  4. Hi Harald,

    I would like to take a look at the binary codes.. how do I get them from you?

  5. Micah. I’ll be happy to hand you the AVR binary, though you’d have to do the chip tanking yourself. I use an STK-500 development board and don’t have any experience with anything else.

  6. any chance I could get a list of what I would need t do this? would you be willing to provide AVR binary? I am VERY interested in implementing this into all of my builds from here on.

  7. Well, i didnt yet try this myself but i think even programing in arduino should be much more easy than direkt on the atiny 🙂 The cool thing is that you can use arduino and breadboard before you switch to the attiny. I am planing on a tremulus lune version with arduino as led controller. One could even imagine an attiny and a digital pot in effects like fuzz etc…

  8. I don’t completely agree. For some people it might be a good investment, but for a lot of people I would think not so much. And the learning curve is still pretty steep.

  9. Don’t know a thing about this, I have some experience with 8051 though. The programming is via serial Dsub? In this case it should have one..I guess. The idea of using a microcontroller or a PLC is the easy reprogramming and to avoid wiring changes. I thing this could be a good start

  10. Well, I suppose you could just tell people to get their own programmers, right? I mean, it’s a good investment, once you get into microcontrollers a whole new world opens up.

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