TxPower SX1276 register

End Devices (Nodes) LMIC
1

Hi team

About the TXPOWER fuction of LOM204A (AT, API, CLI), in theory will right to a SX1276 register that set the tx power.

RegPaConfig…looks Power amplifier identidy

writeReg(RegPaConfig, (u1_t)(0x80|(pw - 2)));

This register will receive a value from 0000 to 1111 (0 to 15), and looks that a gain…

If i put 15, will i have the maximum tx power on rf out ?

plus the gain defined by the module owner, right ?

Thank you much!

PS: the only info that i have of the module is the RF OUT maximum db is 14db…in theory, if i write 15, will have 14db…right ?

2

As far as is known, the LMIC library sets the power levels correctly.

So why if your using the LMIC library for TTN would you need to know the details of the SX127x register settings etc ?

1 Like
3

According to the datasheet the maximum output -power of a SX1276 is 20dBm (100mW).
Using the high efficiency PA the max. power is 14dBm (25mW). This is the output-power you should achieve when setting the register to “15”.
Be careful when using the “boost”-mode with up to 100mW. Depending on where you are in the world, you can exceed the legal power-limits for ISM868 (EU 14dBm erp). Also the battery-drain will rise significantly.
Don’t care about ±1dBm output-power. Much more important is the antenna and it’s position.

1 Like