a question about the communication between nRF24LE1 and nrf51802

[wuyanwei]

hi,

  I have a question about the communication between nRF24LE1 and nrf51802.They communicate using the Gazell protocol,Can you help me solve this problem？

1.The communication rate is 250K,NRF24LE1 sends a packet of data every 50ms, and nrf51802 has no problem receiving ,but when the time is 150ms - 700ms ,the success rate of nrf51802 is only 50%.Then when the time is 700ms - 1000ms,nrf51802 has no problem receiving .

2.NRF24LE1 sends a packet of data every 300ms, and nrf51802 replies to one packet every 50ms, a total of four packets.In this case, there is no problem with sending and receiving, and there is basically no packet loss.The communication rate is 250K.

3.The communication rate is 2M.When the transmission packet interval of nRF24LE1 is less than 150ms, the reception success rate of nrf51802 is less than 30%. When the packet interval is greater than 150ms, the reception success rate of nrf51802 is greater than 80%.

4.There is no problem with the communication between nrf51802 and nrf51802.

[Kenneth]

Hi,

This was strange. What is the retransmit delay configured here? What is the address and CRC used? Is it 1 to 1 communication, or can there be other PRX in the area? Is there any data on the ack?

Kenneth

[wuyanwei]

Hi,

Thank you for your answer.

The time slot of nrf51802 at 250K is 2700 and the number of retransmissions is 15，The time slot of 2m is 600 and the number of retransmissions is 50.It is one-to-one communication. From the phenomenon, nrf51802 does not receive data.NRF24LE1 is an older device.

NRF24LE1 only sends and nrf51802 only receives，The sending logic of nRF24LE1 is to send continuously for 50ms, regardless of ack.

Nrf51802 uses the Gazell library, and nRF24LE1 uses the source code，Therefore, many parameters of nrf51802 are invisible.

I think it should be related to channel jump and time slot,Because when changing the time slot, the reception will change, but changing other parameters has no effect.

The above is the configuration of nrf51802.

The above is the configuration of nrf24LE1.

[Kenneth]

The nRFgo SDKv2.3 have been tested with the nRF5 SDK, and the gazell should be backwards compatible as desribed here:
https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v12.3.0/gzll_02_user_guide.html#gzll_backwards

I suggest to try with the default example as-is again for both nRF24 and nRF51.

I think the problem here may be related to problems with syncrhonization between nRF24 and nRF51, so try to disable sync periods on the nRF24 when transmitting. For instance set max sync period to 0.

Kenneth

[wuyanwei]

• Hi,
• It seems much better to change the time slot to 504us at 2M. I tried 500us before. It's not as good as this. Is there such a big difference? How much should I change at 250K?

[wuyanwei]

Hi,

   Nrf51802 is to replace nRF24LE1. There are many nRF24LE1 equipment on site, and the program cannot be modified. Only nrf51802 can adapt to nRF24LE1.