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dl9rdz / rdz_ttgo_sonde

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No signal on t-beam #18

Closed yeckel closed 5 years ago

yeckel commented 5 years ago

Hi, After some update about a two weeks ago I'm not receiving anything on the T_BEAM_V07. The spectrum is all white (full columns) and later frequencies are toggling pretty fast too. On Helltec LoRa 32 with the same SW and config it works. A HW issue? But another T_BEAM(AXP192) shows the same behavior. Any idea? LoRa RX/TX on T-Beam(s) works just fine. Changing the start frequency to 433 makes no difference. Could there be a problem that T-Beam has SX1276 on board, and the code is for SX1278? Even reverting to old version does not help. Magic? Tnx, 73

yeckel commented 5 years ago

The log output is 0,0,...0. However when I perform a scan in separate sketch using just the guts from the Scanner::scan() and SX1278FSK.h then I'm getting meaningful results.

Strangely even the RegVersion is 0x00, looks like the SPI communication does not work, or the sx1278 is off? (Switching it on with sx1278.ON() == 0, doesn't help) auto r = sx1278my.readRegister(0x42); Serial.print(" RegVersion:"); Serial.println(r, HEX);

yeckel commented 5 years ago

It seems it stop working after calling initGPS() in setup()

yeckel commented 5 years ago

Ok, solved. The gps_txd has to have some meaningful value. Like the correct 15 for T-Beam. Or -1 which is default. I had in settings 18 which is "LoRa chip select". That's explain it.

dl9rdz commented 5 years ago

Ok, thanks für tracking this down. I added a comment to the documentation that gps_txd should be set to -1. The value of gps_txd is passed to the Serial constructor, which will not configure the tx pin if set to -1.