RxDutyCycle Mode debugging

[tommiS (Tommi)]

Hello,
I am using the RAK4631 and trying to implement the RxDutyCycle mode on the receiver to reduce battery consumption. I’ve utilised the same settings as the low power P2P example on the github and I’ve noticed that my receiver only picks up about half of the messages. When I run two receivers at the same time, usually only 1 of them picks up the message.

Things I’ve tried:
-increasing the preamble length to 32 bits
-decreasing the sleep cycle time

I know that my hardware is working well because the receiver in Radio.Rx(0) mode never misses a message.

Just curious, should I expect all of my messages to be coming through with the values provided in the example? or do I have to implement some sort of ACK and/or send multiple copies of the same message?

Thanks,
Tommi

[beegee (Bernd Giesecke)]

RxDutyCycle is tricky. I am not an expert on how to set it up.

I suggest to get and read SX1261-2_RxDutyCycle_V1.0.pdf (Wireless & Sensing Products
RxDutyCycle Final Rev 1.0 AN1200.36) from Semtechs’ website

and to use the Semtech LoRa Calculator to get the symbol length.

I setup two devices with 915Mhz, SF7 BW 125kHz, CR 4/5, payload length 128 bytes, preamble length 8 symbols.
For these settings the calculator gives me a symbol length of 1.02ms

Following the guides from the Semtech document, I set the RX time to 2 symbols and the sleep time to 6 symbols, that should make sure the transceiver catches every packet, as the preamble length is 8 symbols.