I'm trying to synchronize 4 brushless motors' speeds to, eventually, fly a drone. I chose every electronic component and it's starting to look like something.
I control my motors with the pigpio library on a Raspberry Pi. I communicate with the Pi via a small Qt Software I made, and they are linked via Wifi (5-10ms latency).
My problem is : I calibrated each of my ESCs to the same PPM range (1ms as min pulse width, 2ms as max). However, my motors are not reacting the same way : for a same command, one is starting at ~1050, 2 others at ~1100 and the last at 1125.
I could simply use an offset or something, but I have no tachymeter to measure their respective speeds, hence I can't force my motors at the same speed since I'm not sure if they have the same response on the range. Are they even linear, can they all reach their top speeds? How can I study my motors to synchronize them?
Thanks for your help.