Hi there. First time drone builder. Everything went well I thought in the build, but Once I was finished I could not make the drone respond to the transmitter. If I plug the omnibus BetaFlight f3 aoi v1.1 into the pc, I turn on the turnigy evolution transmitter and select the receiver tab on BetaFlight, if I move the sticks on the transmitter, I can see it working through BetaFlight. If I add a lipo to the drone, I can power up the motors with the transmitter.
The second I remove the pc cable, lipo still connected to the drone, the transmitter starts beeping 3 times and flashes red and the RX battery symbol on the transmitter display flashes continously and the drone does not respond to the transmitter. What have I done wrong?