Hello, I’ve APM 2.8 which is working fine when we connect it to mission planner through usb cable. GPS and compass working properly, but telemetry 433mhz can’t communicate with each other, “no heartbeat packet recieved” msg shown after 30 sec timeout. I also check by changing tx-rx connection. If anybody have solution, it is very helpfull to us. Many thanks in advance.
Check the baudrate in config of APM and mission planner connection option.
Is the red light on telemetry blinking?
Yes red light turn on when I connect it to laptop through ftdi to usb converter. Baudrate shown 57 and data is attached.
If you can see some data incoming through comport, maybe problem in settings of your apm. Check this manual http://ardupilot.org/copter/docs/common-telemetry-port-setup-for-apm-px4-and-pixhawk.html
Could be a lot of things:
Not sure what kind of radios you have. Do they have LEDs? If they do and they are flashing that means your radios are connected. This coud be caused by improper wiring on either radio, different NET ID in the radios, wrong baud rate or configuration of the comm port.
Here is a link to an excellent guide. http://ardupilot.org/copter/docs/common-3dr-radio-advanced-configuration-and-technical-information.html
I had the same problem - FIXED.
The Air unit config was different to the ground.
I had to connect the Air unit to laptop using FTDI board.
Then loaded settings using MP & removed the ticked boxes for ECC & Op Resend.
Saved back to board & it immediately connected.