I have several RFM95W miniwireless units and all are having the same issue with poor RF distance at 900Mhz. I have soldered on a copper 82mm "whip" antenna but cannot pass packets further than 1 meter away. I am testing with the example RadioHead sketches for rf_reliable_datagram_(client|server) with the following exceptions:
driver.setFrequency(925.00);
driver.setTxPower(20, true);
driver.setModemConfig(RH_RF95::Bw125Cr45Sf128);
I've tried setting the setTxPower as low as 10 and as high as 20. On the server side I display the RSSI like so:
Serial.print(driver.lastRssi(), DEC);
However, I'm only seeing between -80 and -85 when I should expect to see something around -50 at 1 meter range. I've also tried soldering on RP-SMA connectors with an actual 900Mhz antenna but see a decrease in performance there (same range, worse RSSI).
I'd really like to do some range tests but I can't even get past 1 meter. Any ideas?
Thanks,
John
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