nRF24L01+:the length of received data exceed 32

[I6believe]

hello,we use nRF24l01+ for the communication of IoT.There are a lot of terminals work at a same channel,when the controllers send CMD,we have found:the length of reading from R_RX_PL_WID exceed 32 bytes.we donot know the reason.

so,i want to ask if we have other protection mechanism except of judging the range of length(reading from R_RX_PL_WID).

would you give some advice,thank you very much.

[Håkon Alseth]

Hi,

If a payload is received with size > 32 bytes or size == 0, the FIFO must be flushed. If you read out this payload, the state machine inside the nRF24L01+ may go into a bad state.

This is mentioned in the PS, chapter 7.3.4:

Note: Always check if the packet width reported is 32 bytes or shorter when using the R_RX_PL_WID command. If its width is longer than 32 bytes then the packet contains errors and must be discarded. Discard the packet by using the Flush_RX command.

Cheers, Håkon

[I6believe]

thank you!

what you mean :CRC configuration and RF address configuration is very important.Actually,we use 2 byte CRC,and RF address is 0x4C、0x45、0x44、0x52、0x00,i think it fit in with your advice.

but the project site appear a phenomenon：the length of reading from R_RX_PL_WID exceed 32 bytes. so we should found the reason. the version of software on the project site does not judge the length of R_RX_PL_WID,I do not know whether it is the reason.

please help me to analyze the reason,thank you very much!