Big ESP32 + SX127x topic part 3

[bluejedi]

@blem

But if I remember correctly, the XTAL frequency is mentioned in the Tools menu where you select and cofigure your board.

If you somehow configure the XTAL frequency incorrectly, serial communication will only transmit gibberish. So it’s quite obvious if it’s incorrect and therefore it can’t be the cause of LMIC timing issues.

No gibberish so that is probably unrelated then, but I see no reference for XTAL frequency.

In the Arduino IDE Tools menu (and in the ESP32 Arduino Core files) I only see settings for CPU frequency and SPI frequency but no explicit setting for crystal frequency.

If I interpret the list of possible CPU frequencies it appears like WiFi/BT will only work for CPU frequencies 80MHz and up and lower frequencies can be set only with 40MHz XTALs (but not sure if those assumptions are correct).