how to config retransmit_delay and m_wait_for_ack_timeout_us use ESB

RE: how to config retransmit_delay and m_wait_for_ack_timeout_us use ESB

Håkon Alseth — Tue, 24 Jul 2018 06:20:18 GMT

Yes, the first is for retransmit delay. m_wait_for_ack_timeout_us is an internal variable and you should not touch that one.

RE: how to config retransmit_delay and m_wait_for_ack_timeout_us use ESB

fangrui166 — Tue, 24 Jul 2018 01:07:56 GMT

Hi Sir,

thanks for your apply ,
Each byte in 2 Mbit mode takes 4 us to transfer, so you need to add (4 x payload_size) [us] to accommodate for the size -- this if for retransmit_delay ?

but what value i can use for m_wait_for_ack_timeout_us ?

RE: how to config retransmit_delay and m_wait_for_ack_timeout_us use ESB

Håkon Alseth — Mon, 23 Jul 2018 19:58:32 GMT

Hi.

It is in microseconds, and it is configured when initializing the nrf_esb library.

The retransmit delay depends on how long the ACK is. If the ACK if empty, ie: no ACK payload, then keeping it 250 us is OK.

For ACK payloads up to 32 byte (in different modes), you can use the table in the nRF24L01+ datasheet (chapter 7.4.2) as an example for the retransmit delay.

For higher payload sizes, you need to manually calculate the retransmit delay based on your requirements: Each byte in 2 Mbit mode takes 4 us to transfer, so you need to add (4 x payload_size) [us] to accommodate for the size.

Cheers,

Håkon