Add support for Fine Offset / Ecowitt WH55 water leak sensor (closes #2756)

README.md

@@ -336,6 +336,7 @@ See [CONTRIBUTING.md](./docs/CONTRIBUTING.md).
     [248]* Nissan TPMS
     [249]  Bresser lightning
     [250]  Schou 72543 Day Rain Gauge, Motonet MTX Rain, MarQuant Rain Gauge
+    [251]  Fine Offset / Ecowitt WH55 water leak sensor
 
 * Disabled by default, use -R n or a conf file to enable
 

conf/rtl_433.example.conf

@@ -441,7 +441,7 @@ convert si
   protocol 212 # Renault 0435R TPMS
   protocol 213 # Fine Offset Electronics WS80 weather station
   protocol 214 # EMOS E6016 weatherstation with DCF77
-  protocol 215 # Emax W6, rebrand Altronics x7063/4, Optex 990040/50/51, Orium 13093/13123, Infactory FWS-1200, Newentor Q9, Otio 810025, Protmex PT3390A, Jula Marquant 014331/32, Weather Station or temperature/humidity sensor
+  protocol 215 # Emax W6, rebrand Altronics x7063/4, Optex 990040/50/51, Orium 13093/13123, Infactory FWS-1200, Newentor Q9, Otio 810025, Protmex PT3390A, Jula Marquant 014331/32, TechniSat IMETEO X6 76-4924-00, Weather Station or temperature/humidity sensor
 # protocol 216 # ANT and ANT+ devices
   protocol 217 # EMOS E6016 rain gauge
   protocol 218 # Microchip HCS200/HCS300 KeeLoq Hopping Encoder based remotes (FSK)
@@ -477,6 +477,7 @@ convert si
 # protocol 248 # Nissan TPMS
   protocol 249 # Bresser lightning
   protocol 250 # Schou 72543 Day Rain Gauge, Motonet MTX Rain, MarQuant Rain Gauge
+  protocol 251 # Fine Offset / Ecowitt WH55 water leak sensor
 
 ## Flex devices (command line option "-X")
 

include/rtl_433_devices.h

@@ -258,6 +258,7 @@
     DECL(tpms_nissan) \
     DECL(bresser_lightning) \
     DECL(schou_72543_rain) \
+    DECL(fineoffset_wh55) \
 
     /* Add new decoders here. */
 

src/CMakeLists.txt

@@ -110,6 +110,7 @@ add_library(r_433 STATIC
     devices/fineoffset_wh1080.c
     devices/fineoffset_wh31l.c
     devices/fineoffset_wh45.c
+    devices/fineoffset_wh55.c
     devices/fineoffset_wn34.c
     devices/fineoffset_ws80.c
     devices/fineoffset_ws90.c

src/devices/fineoffset_wh1050.c

@@ -49,6 +49,8 @@ weather data as usual.
 
 TFA 30.3151 Sensor is FSK version and decodes here. See issue #2538: Preamble is aaaa2dd4 and Temperature is not offset and rain gauge is 0.5 mm by pulse.
 
+Note there is a collison with WH55 which starts with `aa aa aa 2d d4 55`
+
 To recognize which message is received (weather or time) you can use the 'msg_type' field on json output:
 - msg_type 5 = weather data
 - msg_type 6 = time data
@@ -270,5 +272,6 @@ r_device const tfa_303151 = {
         .long_width  = 60,
         .reset_limit = 2500,
         .decode_fn   = &fineoffset_wh1050_callback,
+        .priority    = 10, // Eliminate false positives by letting Fineoffset/Ecowitt WH55 go earlier
         .fields      = output_fields,
 };

src/devices/fineoffset_wh55.c

@@ -0,0 +1,119 @@
+/** @file
+    Fine Offset / Ecowitt WH55 water leak sensor.
+
+    Copyright (C) 2023 Christian W. Zuckschwerdt <zany@triq.net>
+    Protocol analysis by @cdavis289, test data by @AhrBee
+
+    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"
+
+/**
+Fine Offset / Ecowitt WH55 water leak sensor.
+
+Test decoding with: rtl_433 -f 433.92M  -X 'n=wh55,m=FSK_PCM,s=60,l=60,g=1000,r=2500'
+
+Note there is a collison with Fine Offset WH1050 / TFA 30.3151 weather station which starts with `aa aa aa 2d d4 5`
+
+Data format:
+
+                   00 01 02 03 04 05 06 07 08 09 10 11
+    aa aa aa 2d d4 55 30 cf 55 04 02 89 be ae a4 20 10
+                   MM FI II II BB VV VV AD XX ?? ?? ??
+
+- Preamble: aa aa aa
+- Sync: 2d d4
+- M: 8 bit Family code 0x55 (ECOWITT/FineOffset WH55)
+- F: 4 bit Flags, Channel (1 byte): (0=CH1, 1 = CH2, 2 = CH3, 3 = CH4)
+- I: 20 bit ID, shown with leading channel in Ecowitt Web App
+- B: 8 bit Battery (1 byte): 0x01 = 20%, 0x02 = 40%, 0x03 = 60%, 0x04 = 80%, 0x05 = 100%
+- V: 16 bit Raw sensor measurement
+- A: 2 bit Sensitivity and Alarm Setting: Left bit, 1 = High Sensitivity, 0 = Low Sensitivity, Right Bit: 1 = Alarm On, 0 = Alarm Off
+- D: 6 bit Unknown?
+- X: 8 bit CRC poly 0x31, init 0
+- ?: 24 bit Unknown?
+
+Format string:
+
+    TYPE:8h FLAGS?2b CH:2d ID:20h BATT:8d RAW:16h SENS:b ALARM:b ?:6b CRC:8h ?:hh hh hh
+
+*/
+
+static int fineoffset_wh55_decode(r_device *decoder, bitbuffer_t *bitbuffer)
+{
+    uint8_t const preamble[] = {0xAA, 0x2D, 0xD4, 0x55}; // part of preamble, sync word, and message type
+
+    if (bitbuffer->num_rows != 1) {
+        return DECODE_ABORT_EARLY; // We expect a single row
+    }
+
+    unsigned bitpos = bitbuffer_search(bitbuffer, 0, 0, preamble, 32);
+    bitpos += 24; // Start at message type
+    if (bitpos + 9 * 8 > bitbuffer->bits_per_row[0]) {
+        return DECODE_ABORT_EARLY; // No full message found
+    }
+
+    uint8_t b[12];
+    bitbuffer_extract_bytes(bitbuffer, 0, bitpos, b, 12 * 8);
+
+    if (crc8(b, 9, 0x31, 0x00)) {
+        return 0; // DECODE_FAIL_MIC;
+    }
+
+    decoder_log_bitrow(decoder, 1, __func__, b, 12*8, "Message data");
+
+    // GETTING MESSAGE TYPE
+    // int msg_type  = b[0];
+    // int flags     = (b[1] & 0xf);
+    int channel   = (b[1] >> 4) + 1;
+    int device_id = (b[2] << 8) | b[3];
+    float battery = b[4] * 0.2f; // 0x01 = 20%, 0x02 = 40%, 0x03 = 60%, 0x04 = 80%, 0x05 = 100%
+    int raw_value = (b[5] << 8) | b[6];
+
+    // Left bit, 1 = High Sensitivity, 0 = Low Sensitivity, Right Bit: 1 = Alarm On, 0 = Alarm Off
+    // int settings = (b[7] >> 4);
+    int sensitivity = (b[7] >> 7) & 1;
+    int alarm = (b[7] >> 6) & 1;
+
+    /* clang-format off */
+    data_t *data = data_make(
+            "model",            "",                 DATA_STRING, "Fineoffset-WH55",
+            "id",               "ID",               DATA_FORMAT, "%05X",    DATA_INT,    device_id,
+            "channel",          "Channel",          DATA_INT,    channel,
+            "battery_ok",       "Battery",          DATA_DOUBLE, battery,
+            "raw_value",        "Raw Value",        DATA_INT, raw_value,
+            "sensitivity",      "Sensitivity",      DATA_INT, sensitivity,
+            "alarm",            "Alarm",            DATA_INT, alarm,
+            "mic",              "Integrity",        DATA_STRING, "CRC",
+            NULL);
+    /* clang-format on */
+
+    decoder_output_data(decoder, data);
+    return 1;
+}
+
+static char const *const output_fields[] = {
+        "model",
+        "id",
+        "channel",
+        "battery_ok",
+        "raw_value",
+        "sensitivity",
+        "alarm",
+        "mic",
+        NULL,
+};
+
+r_device const fineoffset_wh55 = {
+        .name        = "Fine Offset / Ecowitt WH55 water leak sensor",
+        .modulation  = FSK_PULSE_PCM,
+        .short_width = 60,
+        .long_width  = 60,
+        .reset_limit = 2500,
+        .decode_fn   = &fineoffset_wh55_decode,
+        .fields      = output_fields,
+};