Multiceiver FIFO Issue

[Geraldo Pugialli]

In a recent project, me and my team have been trying to send data from 3 PTX devices to a single PRX device (the devices are all nRF24L01+) at a constant rate of 1600Hz from each. We managed to transmit and receive data individually at a constant data date. However, when using 2 or 3 transmitters, the data rate is different per transmitter, with a "continuous" burst data from one of the pipes (the nearest from the PRX), but few or none packets received from the furthest ones. We also tried to retransmit the messages with different delays between them, with no sollution to the problem. Regarding this issue, I would like to know how data is filled in the RX FIFO at the PRX device, as it looks like there is a "data race" where the first incoming data "wins" and blocks the data from the other pipes.

Thanks for your attention.

[Håkon Alseth]

Hi,

 

Sending at a interval of 625 us for each PTX device to only one PRX device is exceeding the bandwidth of the radio, especially if you do not have any synchronization for each transmitter.

As you mention, 3 devices will start sending at the same time, asynchronously, this turns into a on-air collision, and the likely payload to be receives is from the device that is closest in range (if not corrupted by another PTX device).

 

Kind regards,

Håkon