Add Support for Mueller Hot Rod water meter

Add Support for Mueller Hot Rod water meter

Author: ProfBoc75

README.md

@@ -340,6 +340,7 @@ See [CONTRIBUTING.md](./docs/CONTRIBUTING.md).
     [252]  BMW Gen5 TPMS, multi-brand HUF, Continental, Schrader/Sensata
     [253]  Watts WFHT-RF Thermostat
     [254]  Thermor DG950 Weather Station
+    [255]  Mueller Hot Rod water meter
 
 * Disabled by default, use -R n or a conf file to enable
 

include/rtl_433_devices.h

@@ -262,6 +262,7 @@
     DECL(tpms_bmw) \
     DECL(watts_thermostat) \
     DECL(thermor) \
+    DECL(mueller_hotrod) \
 
     /* Add new decoders here. */
 

src/CMakeLists.txt

@@ -171,6 +171,7 @@ add_library(r_433 STATIC
     devices/mebus.c
     devices/megacode.c
     devices/missil_ml0757.c
+    devices/mueller_hotrod.c
     devices/neptune_r900.c
     devices/new_template.c
     devices/newkaku.c

src/devices/mueller_hotrod.c

@@ -0,0 +1,121 @@
+/** @file
+    Mueller Hot Rod water meter.
+
+    Copyright (C) 2024 Christian W. Zuckschwerdt <[email protected]>
+    Copyright (C) 2024 Bruno OCTAU (ProfBoc75)
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+*/
+
+#include "decoder.h"
+
+/**
+Mueller Hot Rod water meter.
+
+S.a. #2719 Decoder desired for Mueller Systems Hot Rod transmitter (water meter), open by "howardtopher", related to Hod Rod v2 transmitter
+S.a. #2752 Decoder for Mueller Hot Rod V1 Water Meter Transmitter, open by "dolai1", related to Hod Rod v1 transmitter
+
+Both version v1 and v2 protocols look same format.
+
+Flex decoder:
+
+    rtl_433 -X 'n=hotrod,m=FSK_PCM,s=26,l=26,r=2500,preamble=feb100'
+
+Raw RF Signal:
+
+    {136}ffffffffffd62002884cc2c092f1201f80
+    {135}fff555555fd62002884cc2c092f1201f80
+    {135}ffeaaaaabfac40051099858125e2403f00
+    {134}000002aabfac40051099858125e54015c0
+    {134}00000000000040051099858125e54015c0
+
+The preamble is not stable because of the GFSK encoding not well handle by rtl_433.
+
+Data layout:
+    PP PP PP YY YY YY  0  1  2  3  4  5  6  7  8  9 10 11 ...
+    aa aa aa fe b1 00 II II II II GG GG GG GF CC ?? ?? ?? ...
+
+- PP: {xx} Preamble 0xaaaaa but not stable, see RF samples above.
+- YY: {24} Sync word 0xfeb100
+- II: {32} Device ID
+- GG: {28} 7 niblles BCD water cumulative volume, US liquid gallon
+- FF: {4} Flag, protocol version, battery_low ??? to be confirmed later.
+- CC: {8} CRC-8/UTI, poly 0x07, init 0x00, xorout 0x55
+- ??: extra trailing bit not used, related to GFSK/FSK encoding.
+
+*/
+
+static int mueller_hotrod_decode(r_device *decoder, bitbuffer_t *bitbuffer)
+{
+    uint8_t const preamble_pattern[] = {0xfe, 0xb1, 0x00};
+
+    if (bitbuffer->num_rows != 1) {
+        decoder_log(decoder, 2, __func__, "Row check failed");
+        return DECODE_ABORT_EARLY;
+    }
+
+    // 3 byte for the sync word + 9 byte for data = 96 bits in total, too short if less
+    if (bitbuffer->bits_per_row[0] < 96) {
+        decoder_log(decoder, 2, __func__, "Len before preamble check failed");
+        return DECODE_ABORT_LENGTH;
+    }
+
+    // Find the preamble
+    unsigned pos = bitbuffer_search(bitbuffer, 0, 0, preamble_pattern, sizeof(preamble_pattern) * 8);
+    if ((pos + 9 * 8) >= bitbuffer->bits_per_row[0]) {
+        decoder_log(decoder, 2, __func__, "Len after preamble check failed");
+        return DECODE_ABORT_EARLY;
+    }
+
+    uint8_t b[9];
+    bitbuffer_extract_bytes(bitbuffer, 0, pos + 24, b, 72); // 9 x 8 bit
+    decoder_log_bitrow(decoder, 1, __func__, b, sizeof(b) * 8, "MSG");
+
+    // poly 0x07, init 0x00, xorout 0x55
+    int crc_calc = crc8(b, 8, 0x07, 0x00) ^ 0x55;
+    if (crc_calc != b[8]) {
+        decoder_logf(decoder, 2, __func__, "CRC check failed : %0x %0x", b[8], crc_calc);
+        return 0;
+    }
+
+    char id_str[16];
+    snprintf(id_str, sizeof(id_str), "%02x%02x%02x%02x", b[0], b[1], b[2], b[3]);
+
+    // 7 nibbles BCD (28 bit) = volume_gal
+    int volume = ((b[4] & 0xf0) >> 4)*1000000+(b[4] & 0x0f)*100000+((b[5] & 0xf0) >> 4)*10000+(b[5] & 0x0f)*1000+((b[6] & 0xf0) >> 4)*100+(b[6] & 0x0f)*10+((b[7] & 0xf0) >> 4);
+    int flag   = b[7] & 0x0f;
+
+    /* clang-format off */
+    data_t *data = data_make(
+            "model",       "",          DATA_STRING, "Mueller-HotRod",
+            "id",          "",          DATA_STRING, id_str,
+            "volume_gal",  "Volume",    DATA_FORMAT, "%u gal", DATA_INT, volume,
+            "flag",        "Flag",      DATA_FORMAT, "%x" , DATA_INT, flag,
+            "mic",         "Integrity", DATA_STRING, "CRC",
+            NULL);
+    /* clang-format on */
+    decoder_output_data(decoder, data);
+    return 1;
+}
+
+static char const *const output_fields[] = {
+        "model",
+        "id",
+        "volume_gal",
+        "flag",
+        "mic",
+        NULL,
+};
+
+r_device const mueller_hotrod = {
+        .name        = "Mueller Hot Rod water meter",
+        .modulation  = FSK_PULSE_PCM,
+        .short_width = 26,
+        .long_width  = 26,
+        .reset_limit = 2500,
+        .decode_fn   = &mueller_hotrod_decode,
+        .fields      = output_fields,
+};