User Manual

Revision 1.0 Page 37 of 78
nRF24L01+ Product Specification
7.5.2 PRX operation
The flowchart in Figure 11. outlines how a nRF24L01+ configured as a PRX behaves after entering
standby-I mode.
Note: ShockBurst™ operation is outlined with a dashed square.
Figure 11. PRX operations in Enhanced ShockBurst™
Activate PRX mode by setting the CE pin high. The nRF24L01+ enters RX mode and starts searching for
packets. If a packet is received and Auto Acknowledgement is enabled, nRF24L01+ decides if the packet
is new or a copy of a previously received packet. If the packet is new the payload is made available in the
Start Primary RX
Standby-I mode
Is CE =1?
TX mode
Transmit ACK
Is Auto
Acknowledgement
enabled?
RX mode
Yes
No
No_ACK set in
received packet?
Is the received
packet a new
packet?
TX Settling
Was there payload
attached with the last
ACK?
RX Settling
Pending
payload in TX
FIFO?
Put payload in RX
FIFO and
set RX_DR IRQ
Packet
received?
Yes
No
No
Yes
Is CE =1?
No
Yes
Put payload in RX
FIFO and
set RX_DR IRQ
Discard packet
No Yes
Yes
TX mode
Transmit ACK with
payload
TX Settling
No
Set TX_DS IRQ
Yes
No
YesNo
ShockBurst operation
RX FIFO
Full?
No
Yes