i am having problems with the mission planner to apm side of the data link. amp to mission planner works fine. i have 3dr 433 radios
i get data from the apm but cannot send any. when i try to send waypoints (or anything else) i get an error timeout.
the radios are are talking to each other (solid green) and link quality is good (no packets lost)
i have looked at the radio data in initial set up and there is a very high value (thousands) against SRX which is serial receive overflow.
i have tried swapping radios about and checked wires to no improvement
i am connecting to a apm 2.6 hex (3.2.1) with mission planner (1.3.24)
i have up dated the radio software to 1.9 and the apm is at the latest version.
any help greatly appreciated