Paul & Sabrina's cheap DIY 144v motor controller

[adamj12b]

Mark,

Technically, a boot loader is a program that gets programed into the boot section of the chip. When it starts up, the boot loader program is the first to start, if it doesn't get any information from the computer in a certain amount of time, it starts the actual program.

That would work though as a usb programmer. Its alot like that programmer I have. I took mine apart to see how it works. Its an amtel at90usb series chip.

I have not gotten too much official testing of my controller besides just driving around the yard and up and down the street in the golf cart.

I do have a few other things in the works that I think will be liked.

-Adam

[sawickm]

Originally Posted by adamj12b

I also cant wait to see your controller design.

-Adam

Hi Adam,

I know that you have been asking about the project that I have been working on. I attached an image of the Revolt Power PCB that I have been kicking around.

Power-PCB.gif

I have been using AutoCAD to figure out the mechanics of that design. My Power PCB design uses your “sandwich” technique attaching SOT227 MOSFET and Diodes to a heatsink instead of your TO247’s. Each block on the Power PCB operates at 100 amps, all are connected in parallel using a multilayer busbar.

Depending how the Power PCB assembly is populated, the options for it could be 200V@1000A or 400V@1000A with MOSFETs, or 500V@1000A with IGBTs. This Power PCB would not be cheep to build, but would offer a high end version of the ReVolt. It looks good on paper anyway !!!

[MPaulHolmes]

Does everyone except me have $10,000 software!? Totally not fair. It looks really fancy to me. Nice and symmetrical.

Fran added a bootloader to the code, and also serial communications code so that it's almost like an operating system now. Basically, with a serial connection (haha... don't worry, you can get a USB to serial plug for those new fangled laptops at a computer store) you can send various words like Kp and Ki, so that you can manually set the PI loop variables, or temperature, or throttle ramp rate, or anything you want. It's easy to add new things to the list if you want to. Now you don't need a programmer either.

[esoneson]

Originally Posted by MPaulHolmes

Fran added a bootloader to the code, and also serial communications code so that it's almost like an operating system now.

Any idea when this code will be tested and/or added to the Wiki so we can take advantage of the new code?

Thanks,

Eric

[MPaulHolmes]

Hi Eric! There are 3 files. I posted the code for the main program. I don't know how to add the other 2 files.

[adamj12b]

I'll add the additional files to the wiki tonight. I'm going to begin testing the code after supper.

-Adam

[MPaulHolmes]

I found out what happens if you accidentally short a sheet of 1 ounce copper pcb across 72v today. It makes a noise like an exploding M-80, and makes a giant circle of vaporized copper around the B- area where the contact was initally made. Don't ask...

[bones007]

I have a question about how the bootloader works. When you use the bootloader to re-program the microcontroller does your new code have to include the bootloader itself each time?

Or is the bootloader protected somehow such that you can upload a program with flaws, fix the program and upload again without screwing up the bootloader.

[bennelson]

Has anyone else run into getting RF noise from their open source controller on the FM band of their radio?

My radio has a "feature" of auto-tuning to the next station if the station you are on doesn't come in anymore. Tonight, I accelerated enough that the radio automatically changed stations on me!

Is there someway to keep static off my radio?

Do I have to wrap tin-foil around my controller? Time to build a Faraday Cage?

PS: Paul, don't worry so much about 72V. I shorted 144V of batteries a while back. I was just glad that I had a 3/4" plywood cover on it!

[MPaulHolmes]

Originally Posted by bones007

I have a question about how the bootloader works. When you use the bootloader to re-program the microcontroller does your new code have to include the bootloader itself each time?

Or is the bootloader protected somehow such that you can upload a program with flaws, fix the program and upload again without screwing up the bootloader.

The bootloader is protected somehow! hehe. You just have to program the chip with the bootloader one time, using something like an STK500 or a homemade programmer, and then after that, you never again need to worry about it.

Ben:
I think you should make sure that R15 is 220 Ohms, and R16 is either 4.7 kOhms or 6.8 kOhms. When I first did a couple control boards, I was using 330 Ohm and 3kOhm, which can be fine, but it depends on the optocoupler that is used. There's a lot of variation from optocoupler to optocoupler, even with the same part number. Using 220 and 6.8 K garantees that it will turn on and off really fast. Alternatively, I would use metal end caps with rubber grommits.