I have two new T100 thrusters with the BlueESC pre-installed (f/w 2015-06-9, s/n 1811/1815), I have not touched the firmware or taken either thruster apart. I am using the I2C interfaces to control the thrusters (from two independent I2C ports so no issue with addressing) and I have grounded the PWM input wire.
When up and running both thrusters work perfectly, I can send thrust commands and sense voltage, temp etc. However I am experiencing some very odd start-up behaviour. At boot my software sends the thrust level 00 to both thrusters then checks for the magic number to be sure the interfaces are up and working. One thruster init’s fine and starts running, the other thruster doesn’t react at all to the init command and only starts up after a few seconds of non-zero thruster commands followed by a zero command. (both return the magic number as expected)
In order to simplify my problem I removed all other hardware, grounded the PWM input and pulled SCL and SDA high and toggled the power. One thruster starts up, flashes red once and beeps, the other thruster does not beep and flashes red once, twice then three times in repeat. To further my confusion, if I remove the thrusters from the water this behaviour reliably swaps between the thrusters…
When both are up and running there are no problems at all and I can read/write data all day long without any issues. This seems to be an issue with the way in which they are starting up, any suggestions?