TreadBot

[dragons_fire]

im using them because they are already done... all i need to do is output a serial command, and the motors drive...

example command:

serout2 motor, motorbaud,[$80,0,lfwd,speed]

$80,0 are commands for the driver. lfwd is left forward. and speed is one of 128 speeds

i send one command and the motor driver keeps it at that speed until i tell it to change.. lots less for the PIC to worry about..

im jsut worried about the "electronic" noise affecting the PIC and other stuff on the board...

my tracks are probably a little small for you... the "tiles" on the floor are 6 inches across, so my tracks are tiny... they came from a tamiya dozer kit, it was the leftover track parts. each side has 3 pieces of track connected together...

when i get home, i will upload a picture of the tracks on one of my other toys... they would be almost perfect for a lawnmower, except that they would rip up all the grass!!!!

[dragons_fire]

heres pictures of my tracks on my bigger robot... (its not really a robot yet, its controlled my RC right now... ) theres a 9v battery on top for a size reference...





this link is for the programmer im using.. its wired almost the same as mine, except they dont have the cap.

http://www.melabs.com/images/icsp1.gif

reading about what they say about ICSP, i need to modify my board some more.. it looks as though i need to connect AVdd and AVss too, and it says i need to pull PGM low with a 100k resistor. i also forgot a cap across the vreg.

[skimask]

this link is for the programmer im using.. its wired almost the same as mine, except they dont have the cap.
http://www.melabs.com/images/icsp1.gif
reading about what they say about ICSP, i need to modify my board some more.. it looks as though i need to connect AVdd and AVss too, and it says i need to pull PGM low with a 100k resistor. i also forgot a cap across the vreg.

You're right on everything you mentioned so far. AVdd and AVss NEED to be tied to Vdd and Vss during programming only. During normal ops, they can be seperated. And pulling PGM low is a good idea (in my mind) whether you are using HV-ICSP or LV-ICSP, maybe throw a jumper in there or something for future 'optionability'.
And put .1uf cap's across every chip, every Vdd/Vss pair, heck throw a couple extra in there when a power or ground trace runs for a few inches without one, if you've got the room for it whether you actually plug one in or not. It'll save you future headaches and give you extra spots to pull a power or a ground.

Since you are wanting to redo your boards, you might want this hint...
For a couple of years now, every time I design a board, I put extra via's on every trace/signal/line/whatever, whether I actually use them or not. Doesn't matter where I put them, I just put them wherever they can fit, and they don't have to be double-sided via's. This way I leave myself a load of future re-config options. I can cut a trace here or there and install jumper wires if I want (or more likely, fix a screw up! ).

And those tracks...that's a good idea. I didn't think of putting cleats on chains like that. How well do the chains track over the sprocket when the bolt heads hit the teeth on the sprockets?

Motor drivers - can't argue with that...

[dragons_fire]

my problem with this board, is that i rushed into it, without fully thinking things through, and doing my research.. now that i have done some research, snd thought about this board more, i feel more confident that its going to work.. im also going to omit the pads in the top that arent being used (pcbexpress automatically makes pads on the top and bottom of holes). i have been thinking about the 90 degree angles all evening (ive been installing IPTV all evening, and even using staples that hold the wires snug can destroy the signal.. wires need to have a certain radius for each corner, and cant be kinked...) so i angled some traces so they have 45 degree bends now..

i will upload another copy of the board later, to see what people think..

if you look closely to the sprockets, some teeth are actually cut out to make clearance for the bolt heads. imworking on changing that design too. i think im going to use only one chain for drive, and make some kind of wheel to support the otehr side. the chains dont stay on well now, because it was almost impossible to make both sprockets line up perfectly... i also want to say, its driven by 2 windshield wiper motors, with 3 x 8.5A 12V sealed Gell cells. one for each motor, and one for the headlights.. we have lots of old coal mines and caves around, so its meant to be able to explore them...

[skimask]

if you look closely to the sprockets, some teeth are actually cut out to make clearance for the bolt heads. imworking on changing that design too. i think im going to use only one chain for drive, and make some kind of wheel to support the otehr side. the chains dont stay on well now, because it was almost impossible to make both sprockets line up perfectly... i also want to say, its driven by 2 windshield wiper motors, with 3 x 8.5A 12V sealed Gell cells. one for each motor, and one for the headlights.. we have lots of old coal mines and caves around, so its meant to be able to explore them...

Maybe spot weld those cleats to the top of the chain links?
And the bigger bot---do I see one (or more) of those cheap Walmart wireless camera's (one of those that transmit direct to channel 3) on your shopping list? I've got one of those...works pretty good with crappy antenna's out to about 200ft with a bit of overvoltage at the TX (11.1v vs 9v, 12v w/3 diodes in series).

[dragons_fire]

never seen wireless cams at walmart.. gonna have to go tomorrow... i already have some wireless cams though, and one of them is a lot more powerful than most of the "consumer" ones.. its great havin a "ham" license...

i tried welding the cleats to the chain, but it wrecked the "bearings" in it, and so the chain couldnt "flex" very well. the bolts work great, i used to have 3/4" ones on every second cleat, and there was no way it would slide then. it had some trouble turning though because of it, and it scratched the driveway pretty good.

so do ineed the cap in on the MCLR to ground? or should i just leave it in??

my chip has a max speed of 40mhz but all i have is 20mhz resonators. most equipment on the board is meant to use serial commands at 2400 to 9600 baud. i would also like to experiment with some mapping. would it be worth it for me to run it higher than 20mhz, or do you think it will be fine?

[skimask]

They're really cheap cams. Resolution isn't all that good, color's a bit off, but they work.

Welding - I didn't think of that. The pins on those chains are probably pretty cheap metal anyways.

MCLR cap - usually, it's there to keep MCLR held off for a split second during power up. The built-in power up timer handles that for 72ms if enabled. And the cap will also help with keeping transient power flux's from tripping MCLR.

40mhz vs. 20mhz - If you've got anything 5-10mhz laying around, try enabling the internal 4XPLL. The board should run at 40mhz, especially since you aren't trying to interface with anything major like static ram or whatever...yet...