These are my notes on connecting an Arduino to an Aquacraft Wildcat RC boat and reading the PWM signals for the Servo and ESC during the arming sequence.
Reading the Servo PWM was as simple as connecting one wire from the receiver signal pin(usually white) for the Servo channel to a PWM input pin on the Arduino and using the same sketch I used to read a Traxxas radio.
The only other wire needed was to create a common ground, connect the ground from the radio receiver to the ground of the Arduino.
Plugging in the boat battery and turning on the transceiver, I then read the values in the Serial monitor.
Sniffing the PWM Signal to the ESC
Next I read the PWM use to control the throttle, and more importantly, determine the Arming Sequence. I did this one a little differently. Instead of connecting the receiver signal pin to the Arduino, I used a Y-harness. This allowed me to read the signal and simultaneously send the signal to the ESC and verify the arming. I connected joined end to the receiver. One end of the split connected directly to the ESC. The other end I used to connect the signal wire to the Arduino PMW input pin.
The Arming sequence was as follows:
Neutral position for about 1 second(1500 PWM). Full-throttle for about 1 second(2000 PWM). Here the ESC gave a two beep confirmation. And finally, neutral again for one second(1500 PWM). This gave a three beep confirmation that the ESC was now active.
Simple as that folks. Next step will be to connecting the Arduino and GPS in the same manner as my two other robots and we’ll have an incredibly fast autonomous boat!