Address
0x04
Description
The SETUP_RETR register is used to configure the delay between auto-retransmits and the number of times that a packet is retransmitted if the ack isn’t received.
Contents
This table is copied from the nRF24L01 product specification (page 54).
| Name |
Bit |
Reset Value |
Type | Description |
| ARD | 7:4 | 0000 | R/W | Auto Retransmit Delay ‘0000’ – Wait 250µS ‘0001’ – Wait 500µS ‘0010’ – Wait 750µS …….. ‘1111’ – Wait 4000µS (Delay defined from end of transmission to start of next transmission) |
| ARC | 3:0 | 0011 | R/W | Auto Retransmit Count ‘0000’ –Re-Transmit disabled ‘0001’ – Up to 1 Re-Transmit on fail of AA …… ‘1111’ – Up to 15 Re-Transmit on fail of AA |
Comments
By default, the software driver uses a delay of 500µS and retransmits up to 5 times. The 250µS delay is too short for acks with payloads of more than 15 bytes, which take more than 250µS to transmit at 1 Mbps. Packets of any size are transmissible at any on-air data rate in 500µS.