I am trying to connect a 3v relay to Aux5 on Pixhawk 2.4.8 in order to operate a pump, but the relay does not work. The multimeter shows between 0 and 1.4 - 1.8 volts when the switch on my transmitter is Off and On, respectively. Same story when I press “Low” and “High” tabs in “Servo/Relay” section in Mission planner.
I have the following parameters in the Mission Planner:
BRD_PWM_Count = 4
Relay_Pin = 54
I have no idea what I am doing wrong. Any help would save my project. Thanks.
I have Channel 7 set to trigger the relay. I have set RC7_Option to 28, but no result, same 1.4 volts. Can you please take a look at the attached pics. Thank you.
On that pixhawk, the servo rail is not powered (only the RC + pin has power, the one on the edge). The aux act as a bus bar that you can power the flight controller from, but you cannot power servo devices from that rail without applying power to that rail from an external BEC. A diode should be used also. More info at https://ardupilot.org/copter/docs/common-powering-the-pixhawk.html
