Nearly finished, chips go in tommorow morning. Debugging will hopefully prove sucessful and they should be in the mail to Melbourne by 3pm if all is good
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So, with the upserge of picaxe controller interest, what happened to this one?

Two prototypes sitting in the draws. Was tinkering with a new version of it last month. Found a few little issues here and there with things. Will get it back on track soon, once my programmer gets put back on the computer and I order in some more little parts for the 3rd prototype. Need to order the fet driver for it too

Catch me on MSN and I can pretty much let you know where it's going and the bare basics of the controller design. You might just be able to build it before I do
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I built one. It went bang! I think my 5V reg died.

More info later.

My spike suppression diodes on the relay coils were backwards, causing a short across the 12V reg, which has probably blown the transistors. Somehow the 5V reg died, putting 12V on everything. The pic has probably died, but I hope my receiver is ok

if you caught it quickly the pic might be ok. they are pretty tough generally ;->.

a small note, generally when i'm testing stuff like this i do the first power up without any of the big expensive chips in their sockets. Then i run the multi meter around the sockets and make sure the voltages are all in the right place and not going to explodificate things.
My worst thing is hooking up the power and ground wires on 16F877A's wrong causing a short circuit through the chip. I do that all the time :-<
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Mechanical engineers build weapons, civil engineers build targets

The receiver is fine and the pic still programs, so I'll assume it's still functional. It turns out that I wired the relay to be a short when not energized . The result was a toasted fet. I'll replace the reg & fet and go again. Weeee

;-PicAxe Pin Definitions
symbol reciver = 3 ; Pulsein from Reciever
symbol motor = 2 ; PWM Output for Motor
symbol relay1 = 0 ; Relay 1 activate
symbol relay2 = 1 ; Relay 2 activate

Something is wrong with the pic. If I put my finger on the input to the driver chip, I get a nice 50Hz square wave on the fet gate Are my pin definitions correct? The rest of the code is the same as page 2.

Anyway Pad 1&2 is the battery.
Pad 5&6 are the negative sides of the coils.
Pad 8 is for the positive sides of the coils.
Pad 3 is for the negative sides of the relay poles.

Where's the resistors for the fets?

What are you Mike? You touch the PCB and suddenly the fet does 50Hz

Probably something in my code, check the PWM section, it was only ever tested a few times without a real load. I just ran a 9v motor of a transistor from the picaxe chip and just pre programmed the motor to ramp up to full speed, then ramp down to zero, rinse and repeat.

I need more picaxe chips before I can play with mine again
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'Tis working now. I needed to change the pulsin command to reflect the new pinouts.

Resistors?! I don't need no stinkin' resistors. They take up valuable real estate, and increase switching times! lol. Currently I'm just running 1 Fet, so there shouldn't be too many oscillations. I scoped it and it looked pretty clean. And the mosfet driver works all that stuff out anyway.

Have a nice picture of the boards



I made 2 so I'll build the other one and have some tank steering fun with Punk.

Oh, and doesn't everyone have 20V 50 Hz @ 5ua running through them?

Nice work Mike.

You etch the board yourself? That was the main problem I always had, I didn't have access to my own protoboard making facilities, and my donut boards were always rats nests
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we just made our first toner transfer PCB tonight.
worked out pretty well too w00t ;->
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Mechanical engineers build weapons, civil engineers build targets

I'd just like to say thanks to Aaron for letting me butcher his design. The failsafe is doing some funky things tho. Without a receiver attached it will sit at a speed, then jump to another one, depending on the planetary alignment. It's fine when the receiver is powered up. I'll get a friend at uni to look at it.

@Valen: I've changed the design around a fair bit, what circuit are you using?

Toner transfer? I'll just stick* to my photo resist.

*Bad pun intended

our own one for a full H-Bridge controller.

use a laser printer and a iron.
Print the image on the paper then iron it onto the PCB.
The toner stays on the PCB and resists the etch.

theres some websites out there about it. Its good in that you only need 1 step rather than several to make the board. We have been trying without the fancy paper or anything and have decent results from our first try.
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Mechanical engineers build weapons, civil engineers build targets

Yeah, I had mass problems with the failsafes... I ended up removing them. They turned off if you killed the transmitter if you didn't get any radio signals sending valid pulses With spektrum, I wouldn't bother either.

Glad to see these actually go somewhere. I really wish I had the time when I was interested to finish them off, but work, life and other things got in the way

Maybe I'll use this as a nudge to dig out my picaxe gear...
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