RE: nRF24L01P PRX TX FIFO

RAB — Tue, 08 Oct 2013 10:44:33 GMT

Thanks for your suggestions. This would make sense because in the previous version we didn't use dynamic payload lengths. All nodes used a static payload length. I will check on the power consumption and the VDD_PA pin. I was not putting the PRX into powerdown mode in my "cleanup" routine. I was merely bring the CE low to go into standby mode. I will add this as well.

We are checking to make sure the packet width is less than 32 bytes as instructed by the datasheet. We are trying to sort through the data by capping the length to 32 bytes and reading them from the nRF24l01P anyways. After the packet has been read we always flush the RX FIFO. I will update the receive routine to just flush the packet right away if the length is reported to be over 32 bytes, rather then try and sort through it.

Thanks, R

RE: nRF24L01P PRX TX FIFO

Kenneth — Tue, 08 Oct 2013 07:30:18 GMT

Difficult to say what the exact issue is here, but a few things to check:

What is the power consumption in this "stuck" mode?
What is the state of the VDD_PA pin? Toggle, high or low?
Does your "cleanup" routine also use power down? If not, can you try it.

You should know that when enable dynamic payload length, the data in the PID field of the radio packet set the actual length of the payload. If you are operating in a noisy environment, or on the edge of range, the bit error rate can increase, and the 8 or 16-bit CRC might not be sufficent to filter out erroneous packets. In this case it's possible to receive payloads with erroneous payload length, due to this we have the following Note in the datasheet:

.. 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. ..

Also if you have a 32byte array in your application to read out payloads, and try to read out a payload longer than 32 bytes then you can experience memory overrun, which can cause any kind of issues. So it's imortant that you don't try to read out this packet, but flush it.

You can search through the datasheet for "Note:" and make sure you have handled them all.