TCXO Control DIO3 causing RXTimeOut IRQ in SX 1262

[prabwyld]

Hello,

I have been using the DIO3 control for TCXO. The delay is being set to 31.25us. The radio is configured to work as a receiver and set to continuous mode. However the radio is firing RxtimeOut IRQ. I have checked the configuration and all IRQ's are being assigned to DIO1. Any idea what can be triggering an rxtimeOut.

#define TCXO_TIMEOUT_MS 0x02
void SX126xIoTcxoInit( void )
{
SX126xSetDio3AsTcxoCtrl(TCXO_CTRL_3_3V, TCXO_TIMEOUT_MS);
}

P.s : If I ignore the first timeout and set it receiver again subsequently then the IRQ is not fired and it works fine.

[prabwyld]

Hello,

Could anyone please give some suggestions as to what may be causing the problem of spurious RX timeout IRQ.

[mluis1]

A TCXO requires a lot more time to wake up than 31.25us.

On sx1262mbxdas-board.c example implementation you can see below code

LoRaMac-node/src/boards/NucleoL476/sx1262mbxdas-board.c

Lines 97 to 104 in 9a6c7dc

	void SX126xIoTcxoInit( void )
	{
	CalibrationParams_t calibParam;
	SX126xSetDio3AsTcxoCtrl( TCXO_CTRL_1_7V, SX126xGetBoardTcxoWakeupTime( ) << 6 ); // convert from ms to SX126x time base
	calibParam.Value = 0x7F;
	SX126xCalibrate( calibParam );
	}

The BOARD_TCXO_WAKEUP_TIME definition is set to 5 ms. This value is suitable in most situations. In case a more precise value is required I would recommend to look at your TCXO datasheet in order to know the precise wake up time.