SX126x.cpp SetTx() latency

[mgergos]

Hi Jan,

Would it be possible to add a build option to utilize RADIOLIB_SX126X_STANDBY_XOSC?
The standby() function currently defaults to _RC adding around 5 ms to each SetTx() call.

It could replace any hardcoded standby() calls with standby(RADIOLIB_SX126X_STANDBY_XOSC).
Additionally, the fallback mode would need to be RADIOLIB_SX126X_RX_TX_FALLBACK_MODE_STDBY_XOSC within config().

Maybe there's a more elegant solution?
Let me know your thoughts.

M.

[jgromes]

I think this can be done, either as a build option as you suggested, or a runtime flag (similar to SX126x::XTAL). I'm actually more in favor of the second approach, since it lets the user create two different SX126x instances with two different standby configurations. I can't immediately think of a use case for that, but it seems there could be some.

I propose to add bool SX126x::standbyXOSC member which defaults to false. If set to true, it will use the XOSC standby mode. Will that work for you?

[mgergos]

Sounds good!
No rush.

[jgromes]

Added in b288485, will be released as part of the 6.4.3 update in the coming days hopefully.

[mgergos]

Just one more edit please Jan (SX126x.cpp line 2090);
data[0] = RADIOLIB_SX126X_RX_TX_FALLBACK_MODE_STDBY_RC;
Should be;
data[0] = this->standbyXOSC ? RADIOLIB_SX126X_RX_TX_FALLBACK_MODE_STDBY_XOSC : RADIOLIB_SX126X_RX_TX_FALLBACK_MODE_STDBY_RC;

[jgromes]

Ah, sorry - forgot about the fallback mode. Fixed in 9fd7db4

[mgergos]

Awesome Jan, that's working perfectly now. Thanks.
For the benefit of others, radio.standbyXOSC = true; should be set prior to radio.begin();
(Should your radio application require speed over power efficiency).