mha1
commented
3 days ago This is not a bug, it's a feature.
3.4 changed the the meaning of ANT for true diversity (two independent receiver paths - radios). If a radio was successful in receiving and decoding an incoming OTA packet it pulls its dedicated interrupt line to tell the processor a packet is ready for further processing. If both radios were able to receive and decode the packet both will pull their interrupt lines. The higher priority radio will be used for further processing, the lower priority radio will be discarded. On the SuperP and SuperD radio2 (ANT1) is the higher priority radio.
With having the priorities in mind there are 4 cases: Both Radio1 and Radio2 were successful -> the higher priority radio's packet (Radio2) will be used -> ANT1 will be reported Only Radio1 was successful -> Radio1's packet will be used -> ANT0 will be reported Only Radio2 was successful -> Radio2's packet will be used -> ANT1 will be reported no radio was successful -> no packet is available -> ANT1 will be reported
So you'll see ANT1 most of the times, ANT0 only if Radio1 was the only successful radio
Takeaway:
- ANT doesn't mean Antenna in case of true diversity receivers
- ANT should have 4 states to reflect what's going on but this would confuse even more users (what? I don't see 4 antennas)
AxelRed65
pkendall64
Current Behavior
I have a BetaFPV Super D receiver 2.4 GHz, using it in Diversity mode. It appears the receiver always locks on Radio/Antenna 2 and never switches to the other antenna, whatever the level is ( the indication shows even full red -120 on the display )... If I revert back to ELRS version 3.3.2 the Antenna/Radio switching performs flawless
Steps to Reproduce
I have a drone with 2 horizontal dipoles oriented each one perpendicular to the other... On the radio I get back the RX received RSSI's, RSNR, ANT telemetries shown on a LUA page, also on Googles OSD I get the used radio and its RSSI value...
How to reproduce :
1) On the field, I fly the drone about 500-1000 meters from the radio, hover there and slowly yaw the drone 360° in place, so that both antennas get cross oriented with the radio in turn. On radio and OSD, the antenna indications remain always stuck on Receiver 2 ( sometime it flashes to receiver 1 for few tenths of a second ). Even if stopping the rotation to have antenna 2 the worst position in respect to the radio, nothing changes, it never switches to antenna 1. Reverting to ELRS 3.3.2, same place, same distance, during the rotation I can clearly see the indications of the receiver switching to the better oriented antenna, and the antenna 1 level is well above -60/50 dBm, so, no way that with 3.4.x it should have not switched antenna.
2) In the Lab, I am able to place the Radio ( Jumper T20S ) near under the drone in a way that the drone antenna aligned with the radio saturates, giving out a value around -120dBm, while the other one gets a good level ( about -10/-20 )... Orienting the radio correctly I can see the saturation of a single antenna while the other has a good signal, but the reported 'ANT' telemetry parameter is stuck to '1' ( Receiver 2 ), whichever antenna is receiving a good signal. This happens also on the Reported values on the OSD, with a '-120:2' red blinking RSSI value. If I revert to ELRS 3.3.2 I can clearly see the receiver switching to the unsaturated antenna, both on the Radio and on the OSD
Possible Solution (Not obligatory)
Check if this is really a bug, or some new feature I found nothing about... Could also be a wrong reported telemetry indication?
Details
The ELRS FW is always uploaded by ExpressLRS configurator via Passthrough or WiFi using 3.4.0, 3.4.2, 3.4.3 and 3.3.2 release versions. All versions >= 3.4.0 have the reported issue.
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