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helium / sx1302_hal

SX1302 Hardware Abstraction Layer and Tools (packet forwarder...)
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Fix rssi offset #10

Closed PaulVMo closed 3 years ago

PaulVMo commented 3 years ago

Reverted changes to the RSSI offset back to -215.4 which is the default used by RAK and the Semtech 1302 base global_conf file to address issue RAK2287 based hotspots displaying consistently higher RSSI values than hotspots with other concentrators

JayKickliter commented 3 years ago

[Following up from #rak-wireless in helium discord]

Thanks for spotting and correcting this discrepancy. I thought you were implying that only EU898 was incorrect. Are you certain that RSSI offset is the same for all regions? I can certainly imagine that the error is applicable on the whole, but I can also image that that with different band-specific RF conditioning they could vary a little.

PaulVMo commented 3 years ago

Good point. I am not certain. Going off this repo https://github.com/Lora-net/sx1302_hal/tree/master/packet_forwarder then, you may be correct that it may not be all. EU868 and US915 seem to use -215.4. While CN470 uses -207. I am not sure what the right value would be for others.

shawaj commented 3 years ago

Based on this comment - https://discord.com/channels/404106811252408320/768197263842607164/799798439876624414

Are we saying -215.4 then?

PaulVMo commented 3 years ago

That's my perspective - specifically for 865/868 and 915/920/923 bands it looks like the offset should be -215.4. For 470 bands, based on the original Lora config, it looks like those are -207 (no change needed).

shawaj commented 3 years ago

@PaulVMo cool will update my PR

JayKickliter commented 3 years ago

Personally, I'd ignore that extra 0.4. It's within the noise of my measurement setup.

PaulVMo commented 3 years ago

Yeah, not that significant. -215.4 is what the original semtech / lora config uses so my thought was revert back to that - there is probably (hopefully) some good reason they included the 0.4 in the first place.

JayKickliter commented 3 years ago

This is looking good. I'll try to get this merged before the the next release or the one after that at the latest.