Add Support for Chamberlain CWPIRC pir sensor

README.md

@@ -343,6 +343,7 @@ See [CONTRIBUTING.md](./docs/CONTRIBUTING.md).
     [255]  Mueller Hot Rod water meter
     [256]  ThermoPro TP28b Super Long Range Wireless Meat Thermometer for Smoker BBQ Grill
     [257]  BMW Gen3 TPMS
+    [258]  Chamberlain CWPIRC PIR Sensor
 
 * Disabled by default, use -R n or a conf file to enable
 

include/rtl_433_devices.h

@@ -265,6 +265,7 @@
     DECL(mueller_hotrod) \
     DECL(thermopro_tp28b) \
     DECL(tpms_bmwg3) \
+    DECL(chamberlain_cwpirc) \
 
     /* Add new decoders here. */
 

src/CMakeLists.txt

@@ -77,6 +77,7 @@ add_library(r_433 STATIC
     devices/cavius.c
     devices/ced7000.c
     devices/celsia_czc1.c
+    devices/chamberlain_cwpirc.c
     devices/chuango.c
     devices/cmr113.c
     devices/companion_wtr001.c

src/devices/chamberlain_cwpirc.c

@@ -0,0 +1,113 @@
+/** @file
+    Chamberlain CWPIRC pir sensor.
+
+    Copyright (C) 2023 Bruno OCTAU
+
+    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"
+
+/**
+Chamberlain CWPIRC pir sensor.
+Issue #2582 open by \@kuenkin
+
+This is the webpage of the product itself: https://www.chamberlain.com/ca/cwp-wireless-motion-alert-add-on-sensor/p/CWPIRC
+
+The pir sensor have a learn feature for pairing purpose with the base station up to 8 sensors.
+
+Data layout :
+
+    Byte position                00 01 02 03 04 05 06 07 08 09 10 11 12 13
+        55 55 ... 55 55 55 2D D4 00 xx xx xx xx xx 01 yy yy yy yy yy CC CC
+       |                  |     |                 |                 |     |
+       |               ,--'     |                 |                 |     '--------,
+       |Sync           |Preamble|Message 0        |Message 1        |CRC-16/XMODEM |
+
+- Message 0   {48} 00 xx xx xx xx xx, always starting with 0x00
+- Message 1   {48} 01 yy yy yy yy yy, always starting with 0x01
+- CRC-16XModem{16} cc cc  from 00 to 11 byte
+
+- Message 0 and 1 change regularly (every 30 / 35 minutes) , ID is not yet decoded from these 2 messages, tbd.
+- Could be a rolling code and the learn feature could help to get the key ?
+- In case of low battery the base emits a short beep, every 35 minutes. So the low battery information is coded into the 2 messages.
+*/
+static int chamberlain_cwpirc_decode(r_device *decoder, bitbuffer_t *bitbuffer)
+{
+    uint8_t const preamble[] = {0x55, 0x2D, 0xD4};
+
+    if (bitbuffer->num_rows != 1) {
+        decoder_logf(decoder, 2, __func__, "Expected 1 Row, here %d", bitbuffer->num_rows);
+        return DECODE_ABORT_EARLY;
+    }
+
+    unsigned bits = bitbuffer->bits_per_row[0];
+
+    if (bits < 136 ) {                 // too small
+        decoder_logf(decoder, 2, __func__, "less than 136 bits, %d is too short", bits);
+        return DECODE_ABORT_LENGTH;
+    }
+
+    unsigned pos = bitbuffer_search(bitbuffer, 0, 0, preamble, sizeof (preamble) * 8);
+
+    if (pos >= bits) {
+        decoder_logf(decoder, 2, __func__, "Preamble not found");
+        return DECODE_ABORT_EARLY;
+    }
+
+    data_t *data;
+    uint8_t b[14];
+
+    pos += sizeof(preamble) * 8;
+    bitbuffer_extract_bytes(bitbuffer, 0, pos, b, sizeof(b) * 8);
+
+    if (b[0] != 0 && b[6] != 1) {
+        decoder_logf(decoder, 2, __func__, "Message 0 and 1 not found");
+        return DECODE_ABORT_EARLY;
+    }
+
+    uint16_t crc_calc = crc16(b, 14, 0x1021, 0x0000);
+
+    if (crc_calc != 0 ) {
+        decoder_log(decoder, 1, __func__, "CRC error");
+        return DECODE_FAIL_MIC;
+    }
+
+    char msg0[20], msg1[20];
+    sprintf(msg0, "%02x%02x%02x%02x%02x", b[1], b[2], b[3], b[4], b[5]);
+    sprintf(msg1, "%02x%02x%02x%02x%02x", b[7], b[8], b[9], b[10], b[11]);
+
+    /* clang-format off */
+    data = data_make(
+        "model",   "Model",     DATA_STRING,   "Chamberlain-CWPIRC",
+        "msg_0",   "Message 0", DATA_STRING,    msg0,
+        "msg_1",   "Message 1", DATA_STRING,    msg1,
+        "mic",     "Integrity", DATA_STRING,   "CRC",
+        NULL);
+    /* clang-format on */
+
+    decoder_output_data(decoder, data);
+    return 1;
+
+}
+
+static char const *const output_fields[] = {
+        "model",
+        "msg_0",
+        "msg_1",
+        "mic",
+        NULL,
+};
+
+r_device const chamberlain_cwpirc = {
+        .name        = "Chamberlain CWPIRC PIR Sensor",
+        .modulation  = FSK_PULSE_PCM,
+        .short_width = 25,
+        .long_width  = 25,
+        .reset_limit = 500,
+        .decode_fn   = &chamberlain_cwpirc_decode,
+        .fields      = output_fields,
+};