Do any "OpLink Air/Ground" have the good RF chip?
« on: January 23, 2022, 10:38:22 am »
When these first came out I bought a set of OpLink Air/Ground (but no Revo Mini, I wanted the SMA on the Ground) and found they did not work with any of my other OpLink stuff (bad clone RFM22 chip).  Big change in RSSI, looks like once a "hop cycle".  This culminated in finding the bad RFM22 chips with the large X2.

My question is whether anyone has bought these lately (or ever) and found that they use the good RFM22 chip.

I might consider buying a Revo Mini, but I would like the option to add RF later if I want, and if that RF is always broken I will just stick with regular Revos.

As an aside, I bet we could determine which hop messes up and code an option to skip that.  This would allow mixing good and bad OpLinks.  We might even have an edge case issue (e.g. 0x0000=0xFFFF or a 0x8000 as positive/negative) that could be corrected.  Are there actually 251 (40kHz) channels (0 to and including 250)?  That would mean that at least one hop is completely outside the band or that the two endpoints are on the band edges.  I tried to flag this long ago...
« Last Edit: January 23, 2022, 11:09:37 am by TheOtherCliff »

karla

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Re: Do any "OpLink Air/Ground" have the good RF chip?
« Reply #1 on: January 24, 2022, 09:27:48 am »
hey, let me check what I have in my bin.
Think I have some.
will take some days...

Re: Do any "OpLink Air/Ground" have the good RF chip?
« Reply #2 on: January 24, 2022, 01:38:24 pm »
Link to picture showing large X2 (bad) and small X2 (good).  So far, that seems a good way to know which is good or bad without testing.
https://forum.librepilot.org/index.php?action=dlattach;topic=4197.0;attach=7316

karla

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Re: Do any "OpLink Air/Ground" have the good RF chip?
« Reply #3 on: January 26, 2022, 05:01:05 am »
The only OPLM I have around now is an Air-side unit.
Can't remember when I got it but must have been some years ago.

It has a big X = bad.

hope it helps

Re: Do any "OpLink Air/Ground" have the good RF chip?
« Reply #4 on: February 18, 2022, 09:30:02 am »
Anyone have an easy scenario to recreate the OpLink "bad RFM22B" issue?  I can get the 46kHz offset, but can't seem to get the repeated 25dB drop (which causes repeated disconnect when that puts it below the noise floor).