Let's Make Robots!

Motor Controller Board

Well I've almost had 3 weeks offline and got a ton of thinking done.  The physical design is basically the same, going to use a PicAxe 14M to control four DC motors with two L293Ds. The picaxe will be optically isolated from the arduino, so if the motors, an IC or a wire shorts out and decides it doesn't want to go alone that it doesn't have the arduino as an option as a buddy in IC heaven or hell.

Basically, the arduino will send a message to the opto-isolated picaxe, then the picaxe will decode the message getting the data it needs to set the direction and speed of the four motors. This is a very simplified explanation of what will happen.

 So far I have 7805 portion up and running so there is power to the picaxe and to the 595, the program/input selector will be 50% complete when I finish up the picaxe programmer circuit tonight. On the 595, a resistor needs to be moved from the ground pin to Q7, the ground pin needs  to be wired to ground and then will have the comm pins to attach to the picaxe. I hope to get that portion done tonight, then I'd be about 20% done on the hardware portion. Having the programmer circuit done and the picaxe connected to the 595 would be an awesome accomplishment tonight.

So far just the 7805 portion done, so it has power, woot!!

Mech out 

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Well at a standstill for now till I can either get the sparkfun usb picaxe programmer working or get an actual picaxe programmer cable. Any advice or information about this would be most welcome. Yes I've RTFM, so that step is already done and did everything it said to do, but if somebody is willing to walk me through it, you are more than welcome to.

 

Mech 

The good news is that I have more pins to play with, the bad news is that the 14M only has two probably PWM channels(I want 4), the blah is that I still can't get the cable to work.

More pins is always a good thing, just have to decide what to do with them now. Less PWMs than I expected is not good, and means I will have to do some creative programming. A bit upset that the cable doesn't work though.

Ah well, back to the proverbial drawing board LOL 

Well, got the homemade development board made for the picaxe 14m, woot! Just have to replace a bad resistor, because the signal and continuity stops at that resistor. Should be able to program the 14m from that board. I went ahead with the dev board idea because I have a few other projects I need the 14M for, such as the robot power supply unit and I hate taking chips out of the socket. Yes, the PicAxes are cheap enough to leave in circuit, but part of the idea of the Motor Control Board is program the chip once and let it do it's job.  

 Mech 

 

Got the picaxe going strong , now just have to figure out what I'm doing wrong with the 595. I've started building a freeduiono type board with terminal blocks.  I think it will be a cool addition to my bot toolbox, getting the motor board in it as well. Once I get the arduino clone done, and the motor board done, I can work on the bot power supply. I'll still be working on building Leo up, even though he can't be fully autonomous, yet. My definition of autonomous is being able to operate(move about), perform tasks and recharge without human contact.

 

Mech 

Well, finally figured out what I was doing wrong with the programming circuit. For some oddball reason, I kept putting the 22kresistor before the 10k resistor, so I was sinking the signal to ground basicly. Ah well, will find out later once the batteries are charged up if it will program or not.  If you're lucky I'll do a walkthrough on setting up the primary circuit for the PICAxe, I may do it anyways, just so that I have the reference *chuckles*.

 Ah well, back to basics for me...again. I'm gonna post on ignoble's post of ignoble deeds so that everybody can learn from this misadventure.

 

Mech Out