muellerhotrod

This repo is to document decoding the transmission from a Mueller Hot Rod Radio Transmission Unit.

Technical info

Model #: AHRHIV1-DL
FCC ID: SM6-HOTRODV1HI
Transmit Frequency: 902 - 928 MHz
Modulation: GFSK
Tranmission Time: 2.5ms every 3 seconds
MCU: PIC16F886
Radio: CC1050

Decoding with RTL_433

You may have to adjust the gain setting.

rtl_433 -f 909M -s 1M -R 0 -X 'preamble={20}aaaaa,n=hotrod,m=FSK_PCM,s=20,l=20,r=3000' -g 20

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  
time      : 2021-02-28 14:34:12
model     : hotrod       count     : 1             num_rows  : 1             rows      : 
len       : 92           data      : feb10014376017005053000
codes     : {92}feb10014376017005053000

Recorded sample

hotrod_g001_909M_1000k.cu8

Data format

?? ?? TT TT TT TT TT CC CC CC ?? ?
fe b1 00 14 37 60 17 00 50 53 00 0

TT - Meter ID / Translator
CC - Consumption

The above is meter ID: 0014376017 and consumption: 005053. The values are base 10, they don't need to be converted from hex. I'm not sure of the other values in the transmission and the Hot Rod v2 appears to encode the data differently.

The Hot Rod transmits it's own ID if the device disconnected from the meter. The printed ID on the device is 2073629812.

fe b1 c0 73 62 98 13 bb 00 00 00 2c

Photos

TODO

• See if there is a CRC
• Figure out the other bytes
• Decode v2 of the MTU