Hello,
I have two Feather 32U4 with 900 MHz RFM69 transceivers (Product ID: 3076) that are not transmitting with the programmed power. Is it possible to exchange or otherwise replace these units? They are from order #2905573 on 8/19/22.
I did not do anything that would damage these transceiver modules like using them without antennae and took ESD precautions. They do transmit but I found excessive packet loss compared to other units which led to pulling out the spectrum analyzer. Signal strength was compared using a reference antenna on the spectrum analyzer and same firmware/hardware setup.
Here's the output from a functioning unit:
and here is the output of one of the two weak units at the same settings:
Low TX power with Feather 32U4 RFM69
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- adafruit_support_mike
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- akcnc
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- Joined: Fri Jan 27, 2023 4:14 pm
Re: Low TX power with Feather 32U4 RFM69
Alright, I tried adjusting the power settings on a bad unit and compared directly to a good unit. It is set to continuous mode, FSK, no frequency deviation to get unmodulated carrier, and 9600 baud. The rest of the setup is the same.adafruit_support_mike wrote: ↑Fri Jan 27, 2023 9:20 pm Try changing the transmission power settings and see if that has any effect on the output.
This is max hold on a good unit reaching around -39 dBm and one of the weak units showing -60 dBm. The good unit had power programmed to +0 dBm while the bad unit was set to +20 dBm. I also tried resoldering the antenna to see if it was a bad connection there causing problems. No luck there.
- adafruit_support_mike
- Posts: 67485
- Joined: Thu Feb 11, 2010 2:51 pm
Re: Low TX power with Feather 32U4 RFM69
That does look like the board has low transmission power.
If you'd reported it during the 30-day return/replace period, I would have been able to authorize a replacement. At this point, I'm afraid I don't have any service options.
If you'd reported it during the 30-day return/replace period, I would have been able to authorize a replacement. At this point, I'm afraid I don't have any service options.
Please be positive and constructive with your questions and comments.