Thanks for the photo David, I'll reply here just for other users benefit in the future.
It does look in the photo that you may well have accidentally shorted the track to the ground plane. Easily done and I'm glad your soldering has improved as a result of putting the Echook Nano together (that's the idea!). Glad you found the soldering video helpful also.
If you can understand the solution I posted above I'd say that may well help you on your way to getting a working board. If you need to send any pictures to clarify the understanding of the solution then please do
Post by Green Dragon Racing on Feb 6, 2020 18:49:00 GMT
So my plan for tomorrow is to carefully remove R24 and check that there is NO resistance between ground and A2. If that is ok I'll delicately solder the 47k resister legs directly to pin A2 and Pin1 on op amp (on the solder side of the board) making sure the legs don't interfere with any of the other pins. Then double check the continuity and resistances etc. Then try checking the voltage between the same 2 pins with the current sensor set up to do the calibration calcs.
Post by greendragonracing on Feb 10, 2020 10:14:56 GMT
Hi Folks, I hope you had a good weekend. So I only had an hour or so to tinker on Friday, all I managed to do was unsolder R24 and solder it directly to the pins. There was no continuity between ground and A2 but I was still getting the same resistance measurements between A2 and pin 1 on op amp. I tried calibration but still had 0v on A2.
I have not yet removed C5 so I think I'll try that today after connecting up throttle and seeing if I can drive the motor via our 4QD Porter 10xxx motor controller and echook PWM out.
On a separate note. In the calibration file there is only input for calibrating 1 thermistor. I thought we could have 2? Is that right or am I being silly?
Also, here is a picture of damage on PCB, and R24 soldered directly to pins.
Good to see the pictures too. No continuity from A2 to ground is good, how about continuity from Op-Amp pin 1 to ground? That would also hold A2 to 0v, and is on the side of the resistor where the damage is. This would also show as ~47k ohms from A2 to ground. I'll send you a PM in a sec.
There is only one thermistor calibration on the assumption that the two thermistors are similar, it does not take too much extra code to duplicate the calculation and add individual calibration for each thermistor.
Let me know how you get on with the 4QD controller
Post by greendragonracing on Feb 10, 2020 22:19:41 GMT
So here's a quick one (hopefully).
As I said, I've got drive to the wheel using PWM out to motor controller using the set up in the attachment. I noticed before that someone in another thread had the same issue I have with the full throttle voltage only being ~2.6V. Am I right in thinking that given the 10k resister and the limited amount of current the eChook uses that 2.6V is the most the circuit needs. If so, the max current is about .26mA. Therefore if I want the full 4V I need to swap the 10k resistor for a ~16k resistor? Also, if I only want the motor to work at 80% of maximum I can change that resistor to what ever value assuming the current will not change.
I suppose what I'm trying to ask/say is the 2.6V is not a an eChook issue and I don't need to mess with the frequency or any of that magical stuff?
I've also attached a screen shot of the legacy throttle that I think we are using.