Paul & Sabrina's cheap DIY 144v motor controller

[jackbauer]

thanks adam i sort of guessed that was the issue. At least it programmed ok. Could you tell me the serial port settings for the rtd software? Does it use any flow control?

[adamj12b]

19200,8,n,1 no flow

my program will rake care of all this.

Www.evvette.com

-Adam

[jackbauer]

ok i got past the lem check by using a few 1k resistors to simulate 2.5v on vref. Can't get the rtd to talk to the controller. I have a null modem cable that swaps tx and rx. Is that correct? So that tx from the controller connects to rx on the pc and vice versa. Should the controller be powered up first or the rtd program? sorry for all the silly questions!

[jackbauer]

ok got it sorted. Removed the micro and shorted pins 2 and 3 then setup hyperterm and did a loopback test. Found a dry solder joint on the hin device. rtd now running. Only thing was i didnt get any data until i manually set the rtd period. not a problem just thought i'd mention. great application by the way. now to program my bmw throttle body and do some starter motor runs!

[jackbauer]

Followed adam's advice re the throttle calibration and it works! bmw throttle position sensor now driving the controller. Thats saved me major money not having to get a potbox. This means that any resistive based tps from any car can be easilly setup to work with this controller. Any of you guys visit Ireland the drinks are on me

[jackbauer]

Could you guys do a v0.9 code with throttle proportional to pwm?

[MPaulHolmes]

It can do throttle proportional to current, and then smoothly transition to throttle proportional to pwm duty, based on settings.

type the following:

t-pos-gain 128
t-pwm-gain 120

and see what that does.

[adamj12b]

No null modem cable. Just stright through. You might need to enter rtd-period 100 from the command line to make the controller read out data.

-Adam

[jackbauer]

Paul thats insane! I can make the starter step around one pole at a time!. Its a bit jerky though at higher throttle. What setting makes it create the perfect woman lol?

edit: after about half throttle it smooths out. I do get a little curtis like squeal if i blip the throttle

[MPaulHolmes]

Hi Jack! The perfect woman:

t-pos-gain NOT_NAGGY
t-pwm-gain RICH

hahaha Just kidding.

By the way, I don't know why I didn't think of this! Fran suggested that since you are using a starter motor, you could change the current limit by looping the wire through the LEM. For example, 500 amp current limit, 1 loop. hehe. That's not even a loop! For 100 amp current limit, 5 turns of wire through the LEM. For 50 amp current limit, 10 turns of wire through the LEM.