Add Flowis protocol decoder (#2357)

Author: merbanan

README.md

@@ -319,6 +319,7 @@ See [CONTRIBUTING.md](./docs/CONTRIBUTING.md).
     [234]  Watchman Sonic Advanced / Plus
     [235]  Oil Ultrasonic SMART FSK
     [236]  Gasmate BA1008 meat thermometer
+    [237]  Flowis flow meters
 
 * Disabled by default, use -R n or a conf file to enable
 

conf/rtl_433.example.conf

@@ -458,6 +458,7 @@ stop_after_successful_events false
   protocol 234 # Watchman Sonic Advanced / Plus
   protocol 235 # Oil Ultrasonic SMART FSK
   protocol 236 # Gasmate BA1008 meat thermometer
+  protocol 237 # Flowis flow meters
 
 ## Flex devices (command line option "-X")
 

include/rtl_433_devices.h

@@ -244,6 +244,7 @@
     DECL(oil_watchman_advanced) \
     DECL(oil_smart) \
     DECL(gasmate_ba1008) \
+    DECL(flowis) \
 
     /* Add new decoders here. */
 

src/CMakeLists.txt

@@ -110,6 +110,7 @@ add_library(r_433 STATIC
     devices/fineoffset_wn34.c
     devices/fineoffset_ws80.c
     devices/flex.c
+    devices/flowis.c
     devices/fordremote.c
     devices/fs20.c
     devices/ft004b.c

src/devices/flowis.c

@@ -0,0 +1,145 @@
+/** @file
+    Flowis water meter.
+
+    Copyright (C) 2023 Benjamin Larsson
+
+    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.
+
+    Heavily based on marlec_solar.c
+    Copyright (C) 2021 Christian W. Zuckschwerdt <[email protected]>
+*/
+
+/**
+Flowis water meter.
+
+There are several different message types with different message lengths.
+All signals are transmitted with a preamble (0xA or 0x5) and then the
+syncword d391 d391. This is a popular syncword used by the CC110x transceiver
+family.
+
+
+Message layout type 1 (15 bytes of length), 4-bit nibble:
+
+               0  1  2 3 4 5  6  7 8 9 A  B  C  ....... 15
+    SSSS SSSS LL YY IIIIIIII ?? TTTTTTTT AA BB ???????? CC
+
+- S 32b: 2 x 16 bit sync words d391 d391 (32 bits)
+- L  8b: message length, different message types have different lengths
+- Y  8b: message type (1 and 2 has been observed
+- I 32b: meter id, visible on the actual meter
+- ?  8b: unknown
+- T 32b: timestamp, bitpacked
+- V 32b: Volume in m3
+- A  8b: Alarm
+- B  8b: Backflow
+- ?  xb: unknown
+- C 16b: CRC-16 with poly=0x8005 and init=0xFFFF over data after sync
+
+Message type 2 uses same message syntax, length type, payload and checksum.
+
+Type 2 messages usually contain long runs of zeros that might cause bitstream desyncs.
+
+*/
+
+#include "decoder.h"
+
+static int flowis_decode(r_device *decoder, bitbuffer_t *bitbuffer)
+{
+    uint8_t const preamble[] = {
+            /*0xaa, 0xaa, */ 0xaa, 0xaa, // preamble
+            0xd3, 0x91, 0xd3, 0x91       // sync word
+    };
+
+    data_t *data;
+
+    if (bitbuffer->num_rows != 1) {
+        return DECODE_ABORT_EARLY;
+    }
+
+    int row = 0;
+    // Validate message and reject it as fast as possible : check for preamble
+    unsigned start_pos = bitbuffer_search(bitbuffer, row, 0, preamble, sizeof (preamble) * 8);
+
+    if (start_pos == bitbuffer->bits_per_row[row]) {
+        return DECODE_ABORT_EARLY; // no preamble detected
+    }
+
+    uint8_t len;
+    bitbuffer_extract_bytes(bitbuffer, row, start_pos + sizeof (preamble) * 8, &len, 8);
+
+
+    uint8_t frame[256+2+1] = {0}; // uint8_t max bytes + 2 bytes crc + 1 lenght byte
+    frame[0] = len;
+    // Get frame (len don't include the length byte and the crc16 bytes)
+    bitbuffer_extract_bytes(bitbuffer, row,
+            start_pos + (sizeof (preamble) + 1) * 8,
+            &frame[1], (len + 2) * 8);
+
+    decoder_log_bitrow(decoder, 2, __func__, frame, (len + 1) * 8, "frame data");
+
+    uint16_t crc = crc16(frame, len + 1, 0x8005, 0xffff);
+
+    if ((frame[len + 1] << 8 | frame[len + 2]) != crc) {
+        decoder_logf(decoder, 1, __func__, "CRC invalid %04x != %04x",
+                frame[len + 1] << 8 | frame[len + 2], crc);
+        return DECODE_FAIL_MIC;
+    }
+    uint8_t* b = frame;
+    int type = b[1];
+
+    /* Only type 1 decoding is supported */
+    if (type != 1) return DECODE_ABORT_EARLY;
+
+    int id   = b[5] << 24 | b[4] << 16 | b[3] << 8 | b[2];
+    int volume = b[13] << 16 | b[12] << 8 | b[11];
+
+    char fts_str[20];
+    int fts_year = b[10] >> 2;
+    int fts_mth  = ((b[9]>>6) | (b[10]&3)<<2);
+    int fts_day  = (b[9]&0x3E) >> 1;
+    int fts_hour = (b[8]>>4) | ((b[9]&1)<<4);
+    int fts_min  = ((b[8]&0xF)<<2) | ((b[7]&0xC0)>>6);
+    int fts_sec  = b[7]&0x3F;
+    sprintf(fts_str, "%4d-%02d-%02dT%02d:%02d:%02d", fts_year + 2000, fts_mth, fts_day, fts_hour, fts_min, fts_sec);
+
+    /* clang-format off */
+     data = data_make(
+             "model",         "",          DATA_STRING, "Flowis",
+             "id",            "Meter id",  DATA_INT,    id,
+             "type",          "Type",      DATA_INT,    type,
+             "volume_m3",     "Volume",    DATA_FORMAT, "%.3f m3", DATA_DOUBLE, volume/1000.0,
+             "device_time",   "Device time", DATA_STRING, fts_str,
+             "alarm",         "Alarm",     DATA_INT,    b[11],
+             "backflow",      "Backflow",  DATA_INT,    b[12],
+             "mic",           "Integrity", DATA_STRING, "CRC",
+             NULL);
+    /* clang-format on */
+
+    decoder_output_data(decoder, data);
+    return 1;
+}
+
+static char *output_fields[] = {
+        "model",
+        "id",
+        "type",
+        "volume_m3",
+        "device_time",
+        "alarm",
+        "backflow",
+        "mic",
+        NULL,
+};
+
+r_device const flowis = {
+        .name        = "Flowis flow meters",
+        .modulation  = FSK_PULSE_PCM,
+        .short_width = 10,
+        .long_width  = 10,
+        .reset_limit = 5000,
+        .decode_fn   = &flowis_decode,
+        .fields      = output_fields,
+};