Table of Contents
Advertisement
CRC Computation
CRC Computation
The CC1000 conforms to the Modbus/RTU protocol and thus uses CRC16 for its error checking. The computed CRC is
appended to the end of the message with the LSB first and then the MSB. Below is the pseudo code for computing the
CRC as used by the standard Modbus/RTU. The pseudo code is written in the Ruby language and can be directly used
as such.
Definition
def get_crc (*byte_array)
sum = 0xFFFF
byte_array.each do |byte|
sum ^= byte
8.times do
carry = (1 == sum & 1)
sum = 0x7FFF & (sum >> 1)
sum ^= 0xA001 if carry
end
end
return [sum & 0xFF, sum >> 8]
end
Usage
>> crc = get_crc(1,3,0,141,0,5)
=> [21, 226]
CC1000 Modbus Reference 2.10e!
<---- [CRC low byte, CRC high byte]
44/122
Advertisement
Table of Contents
