Moving right along in our do it yourself quadcopter build with the Pixhawk flight controller; we'll connect the GPS compass, telemetry radio, the safety buzzer, arming switch and power module.
The telemetry radios are used to connect your quadcopter wirelessly to a laptop or tablet for the Mission Planner ground station. Connect the wire harness that came with the radio to one of the radio modules (it doesn't matter which module that you use here) and then connect the other end of the harness to the TELEM 1 telemetry port on the Pixhawk (inset photo). When connecting all of the components be careful to align the notches on the connector with the notches on the Pixhawk socket or component socket!
Connect the GPS compass to the Pixhawk flight controller by plugging in the larger connector on the GPS cable to the GPS port on the Pixhawk and the smaller connector of the cable to the I2C port. If you have an I2C splitter, connect the smaller cable of the GPS into the splitter and then connect the splitter to the I2C port. The purpose of the I2C port is to power the GPS and other components like cool LEDs or video equipment. So a splitter is....well, a must! The arrow on the top of the GPS compass must point to the front of the quadcopter!
The safety buzzer plugs into the BUZZER port on the Pixhawk and the switch simply plugs into the SWITCH port.
Connect the power module to the POWER port on the Pixhawk flight controller. Easy, huh?
At this point the components connected to the Pixhawk flight controller are; the telemetry radio module, the power module, the Q-Brain ESC, the safety buzzer, switch, an I2C splitter and the GPS compass. Now on to step 3 to connect the Turnigy 9x radio!