Let's Make Robots!

A not so dumb but practical motor controller

I've been working on Leo's motorcontroller and reading a lot lately on bots.  It got me to thinking about using multiple uControllers to do multitasking.  I've slimmed down my original motor controller concept to just a PicAxe 14M, a L293D and some resistors. What makes this motor controller different is that it does more than just control the speed and direction of two motors for an indefinite amount of time.  It's possible during setup to make it that each command only last for five seconds or increments of five seconds. If the motor power supply drops below the threshold of the L293D chip, it will also report an error and if it recieves anything that it's not supposed to on it's data line. Any time there is an error, it goes into standby mode till it's next viable command is recieved, which can be a new setup command, a motor/speed combination or even told to sleep for short periods of time to conserve power so as to avoid having to use a hard reset to wake it from it's long nap.

  • Basic Protocol
  • Begin work on board (soldering and verifying power rails)
  • Finish up initial programming
  • Finish up soldering
  • Test board before chipping it
  • Download program
  • Test and tweak



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Well, tried programming the 14M and it all it did was put all the pins in high mode and I mean all of them.  Tried it with another 14M chip and got the same results. Going to try jacking in a 8M and play with it a bit to see what's going on.  Any advice would be appreciated.


Here's what I have so far:

  • Got the sockets soldered to the board
  • Got the power rails connected
  • Been playing with the code (24 bytes left, so tightening it up)
  • Ran the first test tonight (failed, no motor start)
  • Either bad L293D chip or something isn't right(probably just an id10t error)
  • Took some measurements with inclusive results

Will try again tomorrow and find my other chips if need be.



Mech out

Well got the motor controller board half soldered, just need to attach to the 14M protoboard and the first stage of the hardware prototyping is done. Right now the motor control of the software is done, just have some error handling left to do.  Then to download, tweak hardware and software till it works.

Sounds like a nice bit of kit you're working on. Something a little more like an industrial controller and a little less like a hobbyist controller =)

Thank you, trying to take things to the next level.

Well got the power rails all soldered the first go around, got to love careful soldering and a bit of luck.

I'm having to resolder the outputs though, seems I confused one of the inputs and with an output pin. Not a big deal, no chips have been hooked up so didn't brick anything, yet. Speaking of which, time to finish up the program, solder some wires to the protoboard, download the code(with crossed fingers) and start tweaking. I'm having fun  with interrupt so far, yeah I'm easily amused at times, especially at 4am.