Paul & Sabrina's cheap DIY 144v motor controller

[Greg Fordyce]

Originally Posted by MPaulHolmes

Oh heck ya! I love it when a plan comes together! Please God, don't let anything blow up...

I will find out tomorrow if the magic smoke stays where it should! The controller is all built, or as it says in the assembly directions, "BAM! That was fast!".

The motor is mounted in the car but still have lots to do before it is on the road, battery boxes next on the list. I have had the motor and drive train turning with a 12v battery and jump leads, hopefully now it will be a variable speed control with the 12v battery.

Greg

[MPaulHolmes]

12v?! Are you thinking of entering any races?

By the way, just so you know, the bar next to the capacitors is B+, the middle one is M-, and B- is um... I forgot... Oh ya the only remaining bar (the one furthest from the capacitor bank!)

Also, the 12v power to the control section shouldn't share the same ground as the traction battery pack (or in your case, the OTHER 12v battery. hehe)

[mrbigh]

Paul, are you getting close to completion of tha later PCboard revision and testing yet?

[MPaulHolmes]

Yes. I'm fairly certain that the control board for the synchronous rectification controller (with CAN bus) is without error. The control board for the charger was pretty similar, and that works. I'll be doing that in the next few weeks. The charger and bms is basically done, and is going to be tested on a lithium pack in the next couple weeks in Oregon.

[Flatmann100]

Paul, just thought I'd let you know I've just crossed the 1,000 mile mark using the cougar. No problems no glitches.

[Greg Fordyce]

Originally Posted by MPaulHolmes

12v?! Are you thinking of entering any races?

It works on 12 volts, but as you say the only thing I stand a chance with in a race is one of these.
So I better get working on battery boxes for the 144 volt 120ah lifepo4 pack. That, with a Impulse 9 motor in a car that will hopefully weigh in at under or around 1000kg should be a bit more lively.

Greg

[harlequin2]

Originally Posted by MPaulHolmes

12v?! Are you thinking of entering any races?

By the way, just so you know, the bar next to the capacitors is B+,

)

I went down the road past thecapacitors looking for a bar called B+, but all I saw was the Shady inn. They wouldn't serve me 'cos I said I was sick of watching paint dry.

Finished my controller today. Now to apply lotsa volts!

[Greg Fordyce]

Originally Posted by adamj12b

When the controller is started up, you send the command rtd-period #, where # is an interval setting in milliseconds.

The output string is a fixed format and it looks like :

TR=000 CR=000 CF=000 PW=000 HS=000 RT=0000 FB=00 BA=000 AH=000.0

Where you have:

TR = Controllers calculated throttle position. 0-511
CR = Controllers current reference based on throttle and other factors. 0-511
CF = Current feedback from LEM current sensor 0-511
PW = PWM duty cycle of controller 0-511
HS = Heat-sink Temp in raw ADC counts 0-1023
RT = Raw Throttle counts from the ADC 0-1023
FB = Fault Bits. Hex output with each fault and status code. Normal 00
BA = Calculated Battery amps 0-511
AH = Calculated Amp Hours consumed 0-999.9

The default output is through the serial port. 19200,8,N,1.

If you need some more info, feel free to email me directly.

-Adam

I plan on using RTD Explorer for the initial setup and testing of the controller, but once that is done I would like to connect the serial output to my bms. I need to set the output to 9600,8,N,1 as this is all the BMS can handle. How do I do this and will RTD Explorer still be able to connect at this slower speed if I need to make adjustments?

The only thing the bms needs to know is the BA value, can I just get the controller to send that by itself? Is there a command I could send from the bms to get the battery amp current?

Thanks in advance, Greg

[adamj12b]

Originally Posted by Greg Fordyce

I plan on using RTD Explorer for the initial setup and testing of the controller, but once that is done I would like to connect the serial output to my bms. I need to set the output to 9600,8,N,1 as this is all the BMS can handle. How do I do this and will RTD Explorer still be able to connect at this slower speed if I need to make adjustments?

The only thing the bms needs to know is the BA value, can I just get the controller to send that by itself? Is there a command I could send from the bms to get the battery amp current?

Thanks in advance, Greg

Hi Greg,

To change the serial connection settings would require modifying the firmware and recompiling it. It would certainly work at a slower speed, but you will not be able to use RTD Explorer. RTD Explorer is hard coded to only work at the current speed. It was not meant to be changed because this is the best speed that you can get the most amount of real time data out of the controller.

Again, To make the controller send only BA, RTD Explorer would fail. BA is only put out through the real time data string. This string is what makes RTD Explorer work.

When you are ready and make the changes to the firmware for the serial speed, I can compile a version with the new settings for you. But, if the RTD string changes, I will not be able to help. Contact me by PM when you are ready!!

-Adam

[Greg Fordyce]

Thanks for the info Adam, I will let you know if I need the 9600 baud version, might have come up with a way to get comms with the bms at 19200.

Originally Posted by adamj12b

To make the controller send only BA, RTD Explorer would fail. BA is only put out through the real time data string. This string is what makes RTD Explorer work.

How hard would it be to add some way of asking the controller for specific data, for example if we send the command "BA?", the controller could reply with the value, for example "125". Leave the rtd-period command as it is. I think I would need to get a atmega168 chip though as I understand that the atmega8 chip is full. Luckily I put it on a socket.

Greg