Originally Posted by
pphaneuf
For the pin out, you saw the section 8.5.1.3 in the ROAR rule book?
Originally Posted by
ROAR rulebook
It must use a six position JST ZH connector model number ZHR-6 or equivalent
connector with 6 JST part number SZH-002T-PO.5 26-28 awg contacts or equivalent.
Wire sequence must be as follows:
Pin #1- ground potential
Pin #2- phase C
Pin #3- phase B
Pin #4- phase A
Pin #5- temp control, 10 k Thermistor referenced to ground potential
Pin #6- + 5.0 volts =/- 10%
This standardization is really great for consumers! It prevents a manufacturer from developing a proprietary system. It is interesting that they label phase A, B, and C, as I understand it, it is sensor A, B and C.
The comparator I was talking about is just an implementation detail. It is how the ESCs are doing it, and it is very accurate. Most microcontroller will have pins that can execute code when triggered. The comparator is actually inside the microcontroller. Those pins are monitored internally in the MHz range. The trick is that you tell the microcontroller, each time this pin is triggered, save the time in a variable. The time is very accurate, so you can subtract the old time to the new time, and obtain the phase length in microseconds. The phase length is inversely proportional to the RPM.