px4 pwm输出

原文链接：https://pixhawk.org/dev/examples/write_output

The pwm output is generated by publishing to the actuator_armed and actuator_controls topics. A struct of the actuator_controls_s type is created. The control[i] field accepts values between -1.0 and 1.0, with -1.0 being the lowest and 1.0 being the largest value on that channel. The control[i] can be published to the actuator_control topic. The arm field published to the actuator_armed topic must be set to true. Otherwise the pwm outputs might disarm, when the app is started.