Clas Ohlson WH1080 RFM01 Configuration

The following is the configuration sequence for an RFM01 in a Clas Ohlson WH1080 Weather Station, decoded into readable values according to the datasheet.

The configuration words were sampled directly from the weather station’s SPI bus by user ‘cii’ on the Raspberry Pi forums. Here’s the original post (link)

0x958A, 0xA67C, 0xE105, 0xCC0E, 0xC69F, 0xC46A,
0xC813, 0xC206, 0xC080, 0xCE84, 0xCE87, 0xC081

==============================================
0x958a, 1001010110001010b
Configuration Setting (100b)
------------------------------------------
Frequency Band = 868 (10b)
Low Batt Detect [eb] = 1
Wake-up Timer [et] = 0
Crystal on during sleep [ex] = 1
Crystal Load Capacitance = 12.5pF (1000b)
Baseband Bandwidth = 134kHz (101b)
Clock Out Disable [dc] = 0

==============================================
0xa67c, 1010011001111100b
Frequency Setting (1010b)
------------------------------------------
868.3MHz (10 * 2 * (43 + 0x67c / 4000))

==============================================
0xC080, 1100000010000000b
0xC081, 1100000010000001b
Receiver Setting (11000000b)
------------------------------------------
VDI output = Clock Recovery Lock (10b)
LNA Gain = 0 (00b)
RSSI = -103 (000b)
Enable Receiver Chain [en] = 0 (0xC080)
Enable Receiver Chain [en] = 1 (0xC081)

==============================================
0xE105, 1110000100000101b
Wake-Up Timer (111b)
------------------------------------------
R = 1, M = 5
Twakeup (ms) = M * (2 ^^ R) = 10ms

==============================================
0xCC0E, 1100110000001110
Low Duty Cycle (11001100b)
------------------------------------------
D = 7
Duty Cycle = (7 * 2 + 1) / M * 100%
           = 15 / 5 * 100% = 3%
en = 0 (details not given in the datasheet)

==============================================
0xC206, 1100001000000110b
Low Battery Detector and MCU Clock Divider (11000010b)
------------------------------------------
Clock Output Frequency = 1MHz (000b)
T = 6, Low Voltage Threshold = 2.25V + T * 0.1 = 2.85V

==============================================
0xC69F, 1100011010011111b
Auto Frequency Control (AFC) (11000110b)
------------------------------------------
Enable PLL Offset Frequency = 1
Enable Frequency Offset Register = 1
Fine Mode Enable = 1
Strobe = 1
Range Limit = +15/-16 (in 5kHz steps)
Auto AFC Mode = On, reset on VDI = Low

==============================================
0xC46A, 1100010001101010b
Data Filter (11000100b)
------------------------------------------
al = 0
ml = 1
Filter Type = Digital Filter
DQD Threshold = 2

==============================================
0xC813, 11001000 00010011b
Data Rate (11001000b)
------------------------------------------
cs = 0
R = 19
BR = 10000kHz / 29 / (R + 1) = 17.24kbps

==============================================
0xCE84, 1100111010000100b
0xCE87, 1100111010000111b
------------------------------------------
Output and FIFO Mode (11001110b)
FIFO Interrupt = 8 bits received (1000b)
FIFO fill start condition = Synchron word (0x2DD4)
FIFO fill enable = 0 (0xCE84)
FIFO fill enable = 1 (0xCE87)
FIFO enable = 0 (0xCE84)
FIFO enable = 1 (0xCE87)

There may be mistakes in the above, so if you spot any please let me know.

 

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