For those Cougar controller owners (or owners to be) interested in a simple LCD instrumentation interface for the Cougar, I’d like to give you an option.
Originally this was designed for my own EV conversion, but I made it flexible enough to support options I didn’t need but foresaw other might (metric units for instance).
My intent is to get all the information on operation, BOM, fab files, source code, etc onto the OpenRevolt Wiki page so others can use as they wish (with Paul & company’s approval of course!)
Design Overview:
The display is 2 line x 16 character backlit LCD with oversized characters, controlled by a PIC18F2480 microcontroller. It displays both readings taken with local A/D and information transmitted serially from the Cougar. Displayed info includes:
- pack voltage (isolated circuitry) 0-204V range
- battery amps (Tamura hall sensor input or Cougar’s output) 0-511A range
- motor amps (Cougar output)
- accessory battery voltage
- motor temp in C or F (via thermistor)
- controller temp in C or F (Cougar output)
- pack temp in C or F (via thermistor)
Other features:
- calculation & display of SOC based on battery amp usage (peukert is factored in). Battery amp draw is subtracted from battery capacity every second with remaining capacity written to EEPROM every minute.
- calculation & display of MTE (Miles to empty) based on %SOC per mile/km
- momentary switch to toggle between 2 profiles transmitted to controller
- “Mode” LED to indicate when controller runs with alternate profile
- “Overtemp” LED based on independent thresholds for the 3 measured temps
- Alarm output (NPN sinking)
- PWM output of SOC to interface to existing analog fuel gauge
- Canbus and RS232 interfaces (E-Can controller is integrated in the PIC)
Below are links to demonstration videos (part 1&2) of the system breadboarded running preliminary code.
The schematic is also attached.
As of this writing, I have the final fab’ed PCB populated and mostly tested in my car.
I’ll post a few pics of the completed unit later tonight.
I may revise the board since I found minor issues (header pin hole size, part clearance) but I don’t plan on turning this into a development thread. 13 hour work days and family commitments make it hard enough just getting to my conversion (after 2 years I really need to wrap it up & get it on the road!)