Deciphering the tsdz2 torque sensor circuit

[beemac]

I'll update my schematic and post it here... Now I need to sort out the other inputs - PAS, Speedsensor etc. but I'm hoping they will be far simpler!

 

[beemac]

Annoyingly, the PAS sensor only works with 5v - and I only have 3.3v on the board, pita - but at least it works. Ditto the speedsensor - which despite being documented in most places as a reed switch is probably a hall sensor because it needs 5v in... Luckily the VESC has 5v out which I can grab easily for now.

Anyway - at least I now have Torque, PAS and Speedsensor inputs working. Need to do the buttons and brake sensor input next.... but I don't expect any surprises there since they are all inputs we've used before on the tsdz2 wireless controller...

Sooner or later I'll start a new thread - as this is no longer about the torque sensor, it's about making an interface board that allows a VESC to work with a tsdz2 motor and case...

 

[beemac]

This is the circuit I've tested (with the additional current limiting diode on the 12v rail that I've yet to add). I'm sure there are still errors or problems with it as it stands... but at least I get a reading! I'll test this more later in the week once I've added the diode - and all being well hopefully move onto stage 2, putting it all together; merging the tsdz2-wireless-controller code with the ebike-app code from the motor controller - add a sprinkling of the vesc bldc library and hopefully we're go!

Edit - the current limiting diode didn't work.. so I've removed it from the schematic below. But I also worked out what the problem was. I had an electrolytic cap between the 12v and gnd to smooth out power delivery when i thought that might be an issue and had left it on the board, but I hadn't noticed that the cap was now the other side of the current shunt... So the glowing shunt was as a result of the inrush of current to charge the capacitor, nothing to do with the circuit itself. So looks like I have a good circuit now to code against