NRF24L01P-R datasheet(46/78 Pages) NORDIC

46 / 78 page

Revision 1.0

Page 46 of 78

nRF24L01+ Product Specification

7.8.2

Single transaction with a lost packet

Figure 19. is a scenario where a retransmission is needed due to loss of the first packet transmit. After the

packet is transmitted, the PTX enters RX mode to receive the ACK packet. After the first transmission, the

PTX waits a specified time for the ACK packet, if it is not in the specific time slot the PTX retransmits the

packet as shown in Figure 19.

Figure 19. TX/RX cycles with ACK and the according interrupts when the first packet transmit fails

When an address is detected the PTX stays in RX mode until the packet is received. When the retransmit-

ted packet is received by the PRX (see Figure 19.), the RX_DR IRQ is asserted and an ACK is transmitted

back to the PTX. When the ACK is received by the PTX, the TX_DS IRQ is asserted.

7.8.3

Single transaction with a lost ACK packet

Figure 20. is a scenario where a retransmission is needed after a loss of the ACK packet. The correspond-

ing interrupts are also indicated.

Figure 20. TX/RX cycles with ACK and the according interrupts when the ACK packet fails

TX:PID=1

PTX

PRX

ACK:PID=1

MCU PRX

MCU PTX

130us1

TX:PID=1

IRQ

ARD

Auto retransmit delay

elapsed

No address detected.

RX off to save current

Retransmit of packet

PID=1

Packet PID=1 lost

during transmission

Packet received.

IRQ: RX DR (PID=1)

ACK received

IRQ: TX DS (PID=1)

130us1

1 Radio Turn Around Delay

TX:PID=1

PTX

PRX

ACK:PID=1

MCU PRX

MCU PTX

130us1

TX:PID=1

IRQ

ARD

Auto retransmit delay

elapsed

No address detected.

RX off to save current

Retransmit of packet

PID=1

ACK PID=1 lost

during transmission

Packet received.

IRQ: RX DR (PID=1)

ACK received

IRQ: TX DS (PID=1)

ACK:PID=1

Packet detected as

copy of previous,

discarded

130us1

1 Radio Turn Around Delay

NRF24L01P-R bảng dữ liệu(PDF) 46 Page - Nordic Semiconductor

NRF24L01P-R bảng dữ liệu(HTML) 46 Page - Nordic Semiconductor

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78

bảng dữ liệu tải về

Link URL