Originally Posted by
Roelof
I know, he just made a a tool to switch something inside the transmitter and measure when the change comes up on the channel. I think some bad results will be better when doing it on the track and not at home where many wifi signals are in the air. But he is reading a total latency caused by everything between transmitter control to the servo channel output, it is very variable and can go beyond 10 msec of time, that is huge. That is the difference between hitting the Apex right up to launched by the curbs.
It never went beyond 10ms on the M12. It ranged between 2.2 and 6.5, which is a small range and close to the limits of the servo PWM. I'd expect the M17 with one of the faster servo modes and a faster TX protocol to be even better. But even then, a variance of ~4ms at 50km/h is only 5cm. When the fastest human reaction time has been measured at about 100ms, our servos are typically only around 50-100ms transit speed, and in general most ESCs don't support high speed servo modes, I'm not convinced 4ms is going to make a tangible difference.
I'm also not convinced that WiFi signals will appreciably impact latency. Our radios don't resubmit packets like a TCP network, it's closer to UDP where the packets are fire and forget. If a packet gets lost, the radio is still better off continuing to send the current input state. Even then a typical home WiFi network only has a couple ms of ping round trip, and most of that is in the router queues, not over the air transmission.