esb Fastest packet transfer frequency

[shsh]

Now I want a packet (8 bytes) to be sent out at 8k, but now it is only about 5k, I did not set the ack, is there a way to verify that the ack reaches 8k,The library currently in use is nrf5_sdk_17.1.0

[Håkon Alseth]

Hi,

 

nRF52-series (and beyond) can use the radio in "fast ramp-up" mode, which uses 40 us to start up the radio.

We recommend that you use NCS to get the latest updates, but that being said; there is a modified esb version available in this thread that enables fast ramp-up:

 RE: How to use the CONFIG_ESB_NEVER_DISABLE_TX? 

 

Could you try this and see if it is per your requirements?

 

Kind regards,

Håkon

[shsh]

Thank you, I have reached 8K without confirmation, I want to know if 8K can open ACK. TX transmission failed after ACK was enabled at 8khz。Can you speed up the RX confirmation package。

[Håkon Alseth]

Hi,

 

Glad to hear that this showed improvements for the no-ack scenario.

shsh said:

TX transmission failed after ACK was enabled

Did you run the same code on both sides? This is important.

Do you mean that it takes longer time, or that the evt "NRF_ESB_EVENT_TX_FAILED" is being raised?

 

If you use 2 MBit on-air data rate (0.5 us per bit, 4 us per byte), and we assume 1 byte preamble, 5 byte address, 1 byte length/PCF, and 2 byte CRC, the total time on air is:

tTX = 40us + 8 bit * 0.5 us (1 + 5 + 1 + 2 + 8 byte user payload) = 40 + 68 = 108 us.

If you then add the tRXACK time, of a minimum of (40 us + 8 byte * 0.5 * 8) = 72 us.

 

This will exceed your requirement of 8 kHz (125 us) sending rate.

 

Kind regards,

Håkon

[shsh]

Thank you very much, but how can I communicate with TX without ack? RX sends 1 or 2 packets of data to TX from time to time.