About RSSI of STM32WL.

[Weili]

Hi ST experts.

I used the pingpong sample code to test RSSI and SNR. I set SF=12, BW=62.5Khz.

I used SX1261 calculator tools to calculate, under this condition, its RSSI can reach -140dBm.

But during my actual test, our RSSI reached -120dBm and the SNR was unable to receive data after it reached -20dBm.

This is a module we designed ourselves. Is this normal behavior?

[STTwo-32 · Accepted solution]

Hello @Weili 

the difference between the expected and actual RSSI values could happened in multiple cases such as the antenna characteristics, the interference or noise in the environment that is affecting the signal quality,...

Best Regards

STTwo-32

[RL]

The RSSI tested in STM32WLxx or SX126x chipset means the channel signal rssi, so when the signal strength below the noise, the tested rssi equal the noise's one, otherwise, the tested rssi is the truth, so we need to add the SNR number in the tested data as the truth rssi in this condition.  

Eg, RSSI=-119 dBm, SNR= -22dB, the signal RSSI= -119+(-22) = -141dBm.

hope this answer is useful to you!

BR.