Datasheet

PRELIMINARY PRODUCT SPECIFICATION
nRF24L01 Single Chip 2.4 GHz Radio Transceiver
Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone [phone] - Fax [phone]
Revision: 1.2 Page 27 of 39 March 2006
PACKET DESCRIPTION
An Enhanced ShockBurst™ packet with payload (1-32 bytes).
Preamble Address 3-5 byte 9 bit Payload 1 - 32 byte
CRC 0/1/2
byte
flag bits.
A ShockBurst™ packet compatible to nRF2401/nRF2402/nRF24E1/nRF24E2 devices.
Preamble Address 3-5 byte Payload 1 - 32 byte
CRC 0/1/2
byte
Preamble
• Preamble is used to detect 0 and 1 levels. It is stripped off (RX) and added (TX)
by nRF24L01.
Address
• 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.
16
Flags
• PID: Packet Identification. 2 bits that is incremented for each new payload
• 7 bits reserved for packet compatibility with future products
• Not used when compatible to
nRF2401/nRF24E1
Payload
• 1 - 32 bytes wide.
CRC
• The CRC is optional.
• 0-2 bytes wide CRC
• The polynomial for 8 bits CRC check is X
8
+ X
2
+ X + 1
• The polynomial for 16 bits CRC check is X
16
+ X
12
+ X
5
+ 1.
Table 12 Data packet description
16
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).