Let's Make Robots!

Circuit board 90% complete

So this is the first pic when it was about 50% complete, with the picaxe adapter mounted. The jumpers next to the adapter are used to select which picaxe to use when programming. 


The next image is with the pwm circuit that I had worked on, mounted on the main circuit board.

The 08m(empty socket at bottom right) controls the motor pwm control circuit.

The 14m(top center) sends signals to the motor pwm control circuit.

The 08m (empty socket top left) controls ir comm, this is a work in progress....

The motor controller(empter socket next to the power interface) is connected to the pwm circuit.

The motor controller is the 754410(L293D replacement) .




The next iteration with all of the com channels between the picaxes set as well as the programming i/o set.

I tested this tonight and all three picaxes were detected. Next I'll be fine tuning the communications side and add some tests.

Anyway, here is the backside....lots of soldering hours were put into this...



...and the frontside again, updated version.


The programs for each chip are being debugged at the moment so the next part is to fine tuning and streamline. Should be the fun part. 


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 This has quite a few updates: changed out caps from can to poly, more wiring of parts, added header pins for io on the 14m and 8m that that will be used for ir com and seeking. This is what it looks like when you don't plan your layout btw....

I had to change out the caps to different types due to the room in the buggy that I'm using. This now fits quite well.



 Top side with a more components added. The 3 led's are enabled via jumpers. They are wired to the intercom(axe to axe to other axe) pins that are used for serial output. All picaxes can be programed on this board via the jumpers on the top right and the programming breadboard adapter(see sparfun site)


Just checked my above theory by soldering 100k resistors to the serin, and yes that was it. The circuit is seeming to work perfectly...so now I'll do the final layout of the resistors as this was just a test then....finally to the coding....

I'll add some video of the ciricuit communication as it currently is..yeah just some leads blinking...but it shows that it's working....  :)

You're probably better of with fewer volts.

Just keep licking them bats Voodoo!


lol....oops!......it was the morning, what do ya want, I was excited to get it to work!!  :)

by the luck that I read a certain section of the manual, I may have found out why my circuit isn't work perfectly...and if it is the case....man am I going to kick myself....

Anyway, the running theory on this is that the ser in pins for programing the axes need to be tied to common ground...so when one of them is tied...like when I am checking the debugging, things seem to mostly work....at least for the one I'm connected to....this would make sense....so seeing as it's late, I'll soler some 10k resistors from each of the serin pins to ground and see what happens....I think this is it...if so....my circuit will be complete... 

I'm at a loss for whats going on with this damn board. I added startup delays to the axes so they don't start doing anything crazy the second they get power. but for the life of me, sometimes the boad works and sometimes it doesn't. I power it up in one instance and the led output lights start to blink faster than I coded it, and the frequency goes up as  well....how the hell does that work??!?!?! it just starts blinking, then faster and faster, then it stops....then it does it again, then nothing. I checked the voltage to the chips and they are all showing 4.97v. I did a continuity test on all lines, and that all checked out. I'm going to draw a schematic of the full circuit, and maybe I can see something that I missed in that....but so far....nada.......

How do they just act wonky like this...and it's all of them...they all do this. They work, they don't work, they work. they go batsh!t.....

I did however find the reason for a double blink...and this is an idiot moment on my part. I have the led's hooked up to the serial port output...and I had debug statments that by default use that....oops. I found this issue when I ran the simulation.

So...after this frustration, I'm considering building each axe setup on their own boards, make sure it alll works, then try a rebuild of this circuit again. Ah before this, I'll actually breabboard the 14m and see if it does the same thing there.......only need power and an led as it's been programed...


Modifed the board a little more tonight/this morning, but still getting some really odd stuff with the power when I had the 2 8m's connected.  This didn't appear to be the case with the 8m(A) and 14  but I also have a different led/resistor pair connected to the 8m(B). I did however get the voltage fluctuation issue taken care of...this appeared to be insufficient voltage going to the vreg, so using 6 AA cells vs 4 AA or 1 9v battery seemed to solve the issue at the moment.

I did the first test with the 14m and the 8m(A) that'll be sending out the pwm signal. So far so good with that... the 8m(A) recieves serial controls values and blinks the test led.

Next is to set the com program for the second 8m(B). This should be an intersting test as the second 8m will send and recieve data.

After getting the second test squared away the next big test will be the 3 chips all communicating together....fun little experiment that'll be.

Your soldering looks great but be sure to put enough solder to fill up the pad. Sometimes the wire will look like its soldered on there only to fall off and short out the battery pack. This killed my line follower, a V+ wire became loose and touched the ground on my battery pack which was right below it. The batteries exploded and coated my board in battery acid, destroying pretty much everything. The board is being salvaged.

Thanks! Yeah, I have to look at the board and see where I missed(I've found some spots like you said). I've been worried about shorting this board out as it's gotten a bit crazy with the wiring. Tonight I think I'll see about doing that touchup and testing a new battery source...

I've yet to have a battery explode....but damn if I didn't have one cause a smoke cloud.....nasty smelling stuff those nicd's....  :/

first test done last night after updating the board futher....something wierd is going on...I think on the hw side....didn't have time to debug it will have to check it out today...darn darn darn!!!!!


Voltage is dropping down at the vreg which is causing inconsistant results..not sure if its the battery source or if it's the circuit as a whole.