PRELIMINARY PRODUCT SPECIFICATION
nRF24L01 Single Chip 2.4 GHz Radio Transceiver
PACKET DESCRIPTION
An Enhanced ShockBurst™ packet with payload (1-32 bytes).
Preamble
1 byte
CRC 0/1/2
byte
Address 3-5 byte
9 bit
Payload 1 - 32 byte
flag bits.
A ShockBurst™ packet compatible to nRF2401/nRF2402/nRF24E1/nRF24E2 devices.
Preamble
1 byte
CRC 0/1/2
byte
Address 3-5 byte
Payload 1 - 32 byte
Preamble
Address
•
Preamble is used to detect 0 and 1 levels. It is stripped off (RX) and added (TX)
by nRF24L01. The preamble is 8 bits long.
The address field contains the receiver address.
•
•
•
The address can be 3, 4 or 5 bytes wide
The address fields can be individually configured for all RX channels and the
TX channel
•
•
•
•
•
•
•
•
•
Address is automatically removed from received packets.14
PID: Packet Identification. 2 bits that is incremented for each new payload
7 bits reserved for packet compatibility with future products
Flags
Not used when compatible to nRF2401/nRF24E1
1 - 32 bytes wide.
The CRC is optional.
Payload
CRC
0-2 bytes wide CRC
The polynomial for 8 bits CRC check is X8 + X2 + X + 1
The polynomial for 16 bits CRC check is X16+ X12 + X5 + 1.
Table 12 Data packet description
14 Suggested use of addresses. In general more bits in the address gives less false detection, which in
the end may give lower data Packet-Error-Rate (PER).
A. The address made by (5, 4, or 3) equal bytes are not recommended because it in general will
make the packet-error-rate increase.
B. Addresses where the level shift only one time (i.e. 000FFFFFFF) could often be detected in
noise that may give a false detection, which again may give raised packet-error-rate.
C. Addresses as a continuation of the preamble (hi-low toggling) will raise the Packet-Error-Rate
(PER).
Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway
Revision: 1.1
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Phone +4772898900
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Fax +4772898989
November 2005
Page 26 of 38
ETC [ ETC ]
