Hi,

The RxDutyCycle feature of the SX126x is defined in the AN1200.36 application note.

This applcation note shows an extract of a LoRa Power Consumption Calculatore. I have not been able to find this calculator, which should be an Excel spreadsheet by the look of it.

Can you tell me where to find this ?

Also, could you give some example of Sleep duration / RX duration that are valid to use with the SetRxDutyCycle feature ?

I have setup my own Excel spreadsheet to compute the maximal sleep period (depending on the preamble length, the spreading factor and the bandwidth) and the corresponding minimal RxPeriod.

When I replace my Rx(0) function by SetRxDutyCycle() with the output of my excel sheet, I no longer have a 100% packet transmission rate (with both devices next to each other), so I assume something is wrong with my calculation.

Here is what I do, feel free to tell me what’s wrong :

With SF7 and a bandwidth of 125kHz, a symbol duration is 1024µS.

I used the following two formulas as base :

Tpreamble >= sleepPeriod + 8 symbols in LoRa

With a preamble length of 8 symbols, I calculate the following :

1024 * (8 + 4.25) = 12544µS for the preamble duration

Max sleep period = T preamble - 8 symbols = 4352µS. As the register configuration requires a multiple of 15.625µS, I use 4343.75µS (giving a register value of 278).

Min Rx Period = (T preamble + T header - T sleepPeriod) / 2 = ( 12544 + 8192 - 4343.75 ) / 2 = 8192. As the register requires a multiple of 15.625, I use 8203.125µS (giving 525 as register value).

Could you help me figure out what’s wrong ?

Regards.