Paul & Sabrina's cheap DIY 144v motor controller

[flores]

So.. work done today:

Took the controller out and made a wooden mockup to test fit


Guess this is gonna be it


Welded a bracket


Weld that in the car


Its gonna be like so:


And by the time is was done, I thought well, I could just have bolted it to the rear panel .. haha

[jedsmd]

Loaded the software (Thank-you Paul) and took the first test run today.

As Flores had reassured, loading the program with MpLab/Pickit3 was simple and uneventful.

Turned on the truck, a few seconds later the main contactor closed - so far, so good. With the truck in neutral I very slowly stepped on the accelerator, the second contactor closed - also good
I continued slowly depressing the pedal -
I continued slowly depressing the pedal - At last the motor begins turning!!!!

It works! Time for a test drive!

So backed out the drive - incredibly smooth my old controller was never this well behaved.

Out in the street put it in 2nd gear and put the pedal on the floor. With 300 motor amps on the gauge, acceleration can best be described as gentle. Drove it up and down the street some. Great to be running again but definitely need more amps!

Paul can I get a copy of the program that is a little more aggressive? I would like max current at about 800 amps. My second contactor closes at about 3% throttle so less dead space on the throttle would also be good.
Thanks
Jerald

[flores]

Jerald,

If you connect a computer to the serial port you can adjust the max amps yourself. Do you have a computer with com port ? or serial USB cable?

[MPaulHolmes]

But make sure the max motor amps isn't programmed to 800!!!!. That would mean 800 PER IGBT!! FOR 800 motor amps, you would program max motor amps to um... what is 800/3? I'll send over an 800amp default motor amp hex file so u dont need to get a serial cable.

Oh ya, and I will reduce the deadzone. But not all the way to 3%. This needs to stay conservative. If it seems like there is still too much when I send this, I can readjust it. Also, you can program the deadzone thru the serial connection.

[jedsmd]

Originally Posted by MPaulHolmes

But make sure the max motor amps isn't programmed to 800!!!!. That would mean 800 PER IGBT!! FOR 800 motor amps, you would program max motor amps to um... what is 800/3? I'll send over an 800amp default motor amp hex file so u dont need to get a serial cable.

Paul
Great that will get me going down the road

If you connect a computer to the serial port you can adjust the max amps yourself. Do you have a computer with com port ? or serial USB cable?

Flores
I have a laptop with a serial port. But I'm clueless. What software would I need?
Jerald

[MPaulHolmes]

I've always used realterm:
RealTerm: Serial/TCP Terminal - Browse Files at SourceForge.net

(version 2.0.0.70 is the latest version)

The settings are 8N1, 19.2kbps. (8 data bits, no parity, and 1 stop bit)

[jedsmd]

Originally Posted by MPaulHolmes

I've always used realterm:
RealTerm: Serial/TCP Terminal - Browse Files at SourceForge.net

(version 2.0.0.70 is the latest version)

The settings are 8N1, 19.2kbps. (8 data bits, no parity, and 1 stop bit)

Okay so realterm reads whats in the chip, allows you to edit, then you can write back to the chip?

Are the variables that can be tweaked obvious?

I will download realterm and play with it.
Thanks
Jerald

[MPaulHolmes]

(note: This may be an area that bugs are discovered. I didn't debug this part much)
I don't think I have keystrokes being echoed to the screen, so if you type commands, it may not show up on the realterm screen. I need to fix that. But flores just entered the command in a little box, which I think takes care of the issue. I've never noticed that little box before.

If you hit enter with the serial connected, it tells you what firmware version it is.

If you type "config", it shows a list of the programmable variables, and what their current values are.

"save": saves the current values to EEProm, so it will still be there after turning it off.

Example of adjusting the zero throttle point for JEDSMD and the MAX throttle point for others:

t-min-rc 440
save

Example of adjusting the MAX throttle point for jedsmd and ZERO throttle point for others:

t-max-rc 683
save

Adjusting current ramp rate. (Oh crap, I haven't made it so foot off pedal has large ramp rate no matter what. I would leave it set to 16384 (the default) at the moment, until we make "foot off pedal" ramp rate to be 16384 no matter what c-rr is set to):

c-rr 16384
save

If you want to see live streaming values of feedback, you would do something like this (a new set of values every 1000 millisec, also known as every second. haha):

rtd-period 1000

To change the time to 4.6 seconds before the contactor closes (this is only useful if you are precharging during the 4.6 seconds. If you just have the capacitors charged all the time, you could set it to something NONZERO but small, like 1. if it's set to 0, it's disabled, and I think it won't close the contactor. I'll have to doublecheck that though):

pc-time 46
save

To change the max motor amps ***PER IGBT*** (in this example, the total max motor amps would be 267*3 = 801. I need to fix that.):

mot-amps-lim 267
save

There are others, but this is a start.

[flores]

Another bracket made


And that looks good if I may say

[MPaulHolmes]

Awesome!!! And it's even a blue beetle! That's just like my old car. Could I convince you to race someone off the line and film it. First, make sure you talk smack to them. Pick a corvette or something. Then say, "I bet my completely regular stock beetle can beat your car across the intersection." But make sure you don't do it if there are cops around.