FrSky Archer Plus GR6. Random Barometric Altitude. #1142
Description
Hi.
I've been looking into this rather random fault with the FrSky Archer Plus GR6 Receiver when paired with the Multi Module.
The scenario is something like this.
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You have a working state e.g. Tx and Rx working normally and the Sport telemetry is okay. Baro' Altitude and Vario readings show small changes as you would expect with the Rx placed on a desk.
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Power cycle the Tx. This not always needed as the fault can be present from clean start, but the Rx needs to be powered on.
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Randomly (as in this does not happen every time) the displayed Baro Alt and to a lesser degree the Vario readings will be random and change rapidly.
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Power cycle the Tx or Rx again and a stable state may return.
Looking into this more deeply with a logic analyser attached, it can be seen that under a normal condition there would be about 46 Sport Packets in 1 second. Under a fault condition this rises to about 66 packets. What can also be seen is multiple consecutive and identical packets.
I lack a way of decoding all Sport packets in the Analyser, but at one stage I had the MP telemetry stream connected to another Transmitter (listening to Multi Telemetry) and the fault could be seen on both Transmitters.
I have ruled out the Tx software as being at fault. I also tried a Frsky XJT module and could not recreate the fault.
Also tried a Deviation Type transmitter running the same RF protocol with a SPI directly connected CC2500. Again no fault.
So it looks like the FrSky Archer Plus GR6 seems to provoke a fault scenario with the Multi module. Maybe a state machine in the multi code cannot handle something perculiar about this Rx ?.
I have yet see this fault with other Rx's and Sport sensors.
Rx firmware - ArcherPlus_GR6_3.0.1.frsk
MPM firmware - v1.3.4.31 as can be seen from type MP type 1 packet in logic trace.
Protocol FrSkyX2 LBT 8 Channel.
I realise this is a curious fault, but maybe others have seen it and therefore I am not going crazy !.