Starting with CAN bus on the cheap, Arduino & instrumentation

Post Reply
User avatar
Posts: 45
Joined: Tue May 14, 2019 12:52 pm
Location: Dublin, Ireland
Has thanked: 126 times
Been thanked: 10 times

Starting with CAN bus on the cheap, Arduino & instrumentation

Post by marcexec »

So I have a very specific use case and wanted to get my hands dirty with CAN.
I got myself an Isabellenhuette (commonly referred to as ISA) current sensor (shunt) from eBay.
It's the U0 version, i.e. it doesn't have voltage sensors so kind of pointless for most OpenInverter based conversions here.
(IVT-S-500-U0-I-CAN2-12/24-MRQ, datasheet)

However, I have a dumb (square wave) Kelly controller on my bike and want to learn, so why not.
My goal is to drive the 0-15k tach(ometer) / rev counter (Drehzahlmesser in German) according to the current draw, which happens to peak at 150A with the controller I have.
Note the "12V" (or low voltage / LV) on the bike is actually 4S NMC, so tops out at 16.8V, good thing i have a version that's 24V capable...

Now for the smarts:
  • MCP2515 CAN bus module as that seems to be the most common in the Arduino world
  • "blue pill"/"black pill" STM32F411ceu6 development board

both of Aliexpress, expected some time in January.

The "F4" is obviously way overkill for a simple Arduino sketch but we might add some features later, like:
  • adding a display, it would replace the engine temp gauge
  • I believe the ISA shunt can report on supply voltage, which would be nice
  • measure the HV battery voltage - currently 24S, 40S planned for SOC and net consumption calcs
  • button to flick through screens/values
I'll try to be very verbose to have this thread beginner-friendly so it would be easy to follow. Sketches etc. will be attached as well.
A motorcyclist is never late, Frodo Baggins. Nor is he early. He arrives precisely when he means to.
My Suzuki RF400 build over at ES
All the gear, all the time!
Post Reply