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insightsip / ISP4520-examples

LoRa and LoRaWan implementation examples using ISP4520
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ADR bad impact RSSI and SNR #30

Open alexlbc3 opened 2 years ago

alexlbc3 commented 2 years ago

Hi, I am testing the ADR on the ISP4520-US.

Here is the test procedure:

next LoRa payload observations:

The distance between gateway and device was unchanged, the power should be reset to maximum, but something gone wrong, RSSI should be better and not lower. We loose 50% of paylaod at 20cm from gateway, wrong than before ADR tests. If we do a join request, RSSI and SNR is on good range.

image

Jonathan-fattouh commented 2 years ago

Hello, Spreading factor shouldn't affect RSSI. The parameter that affects the RSSI would be the transmit power of the device (which is also a parameter controlled by ADR). However even with minimum transmist you would not even get close to a drop of 90dB. Perhaps the power amplifier of the sx1262 collapses at maximum power. What hardware are you using? (a custom board or one of our test board)? What voltage are you supplying? Are you using a small battery?

Also you should also observe this issue at the very beginning? the first join request should also be SF10 / TXPower max

alexlbc3 commented 2 years ago

Hi, We use a custom board. I don't think is a hardware issue because we don't observe this at beginning and if we redo a join (without change anything) the RSSI and SNR come back to normal value (as you can see at end of screen shot)