X-Git-Url: https://git.rvb.name/rtl-433.git/blobdiff_plain/ca13278b24eb61443559bcb61e64627fba3d8823..6d15c6f967221af825cf84e3ed12b96c763b127b:/src/devices/nexus.c

diff --git a/src/devices/nexus.c b/src/devices/nexus.c
new file mode 100644
index 0000000..ea3a096
--- /dev/null
+++ b/src/devices/nexus.c
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+/* Nexus sensor protocol with ID, temperature and optional humidity
+ * also FreeTec NC-7345 sensors for FreeTec Weatherstation NC-7344.
+ *
+ * the sensor sends 36 bits 12 times,
+ * the packets are ppm modulated (distance coding) with a pulse of ~500 us
+ * followed by a short gap of ~1000 us for a 0 bit or a long ~2000 us gap for a
+ * 1 bit, the sync gap is ~4000 us.
+ *
+ * the data is grouped in 9 nibbles
+ * [id0] [id1] [flags] [temp0] [temp1] [temp2] [const] [humi0] [humi1]
+ *
+ * The 8-bit id changes when the battery is changed in the sensor.
+ * flags are 4 bits B 0 C C, where B is the battery status: 1=OK, 0=LOW
+ * and CC is the channel: 0=CH1, 1=CH2, 2=CH3
+ * temp is 12 bit signed scaled by 10
+ * const is always 1111 (0x0F)
+ * humiditiy is 8 bits
+ *
+ * The sensor can be bought at Clas Ohlsen
+ */
+
+#include "rtl_433.h"
+#include "util.h"
+#include "data.h"
+
+extern int rubicson_crc_check(bitrow_t *bb);
+
+static int nexus_callback(bitbuffer_t *bitbuffer) {
+    bitrow_t *bb = bitbuffer->bb;
+    data_t *data;
+
+    char time_str[LOCAL_TIME_BUFLEN];
+
+    if (debug_output > 1) {
+       fprintf(stderr,"Possible Nexus: ");
+       bitbuffer_print(bitbuffer);
+    }
+
+    uint8_t id;
+    uint8_t battery;
+    uint8_t channel;
+    int16_t temp;
+    uint8_t humidity;
+    int r = bitbuffer_find_repeated_row(bitbuffer, 3, 36);
+
+    /** The nexus protocol will trigger on rubicson data, so calculate the rubicson crc and make sure
+      * it doesn't match. By guesstimate it should generate a correct crc 1/255% of the times.
+      * So less then 0.5% which should be acceptable.
+      */
+    if (r >= 0 &&
+        bitbuffer->bits_per_row[r] <= 37 && // we expect 36 bits but there might be a trailing 0 bit
+        bb[r][0] != 0 &&
+        bb[r][2] != 0 &&
+        bb[r][3] != 0 &&
+        !rubicson_crc_check(bb)) {
+
+        /* Get time now */
+        local_time_str(0, time_str);
+
+        /* Nibble 0,1 contains id */
+        id = bb[r][0];
+
+        /* Nibble 2 is battery and channel */
+        battery = bb[r][1]&0x80;
+        channel = ((bb[r][1]&0x30) >> 4) + 1;
+
+        /* Nible 3,4,5 contains 12 bits of temperature
+         * The temerature is signed and scaled by 10 */
+        temp = (int16_t)((uint16_t)(bb[r][1] << 12) | (bb[r][2] << 4));
+        temp = temp >> 4;
+
+        /* Nibble 6,7 is humidity */
+        humidity = (uint8_t)(((bb[r][3]&0x0F)<<4)|(bb[r][4]>>4));
+
+        // Thermo
+        if (bb[r][3] == 0xF0) {
+        data = data_make("time",          "",            DATA_STRING, time_str,
+                         "model",         "",            DATA_STRING, "Nexus Temperature",
+                         "id",            "House Code",  DATA_INT, id,
+                         "battery",       "Battery",     DATA_STRING, battery ? "OK" : "LOW",
+                         "channel",       "Channel",     DATA_INT, channel,
+                         "temperature_C", "Temperature", DATA_FORMAT, "%.02f C", DATA_DOUBLE, temp/10.0,
+                         NULL);
+        data_acquired_handler(data);
+        }
+        // Thermo/Hygro
+        else {
+        data = data_make("time",          "",            DATA_STRING, time_str,
+                         "model",         "",            DATA_STRING, "Nexus Temperature/Humidity",
+                         "id",            "House Code",  DATA_INT, id,
+                         "battery",       "Battery",     DATA_STRING, battery ? "OK" : "LOW",
+                         "channel",       "Channel",     DATA_INT, channel,
+                         "temperature_C", "Temperature", DATA_FORMAT, "%.02f C", DATA_DOUBLE, temp/10.0,
+                         "humidity",      "Humidity",    DATA_FORMAT, "%u %%", DATA_INT, humidity,
+                         NULL);
+        data_acquired_handler(data);
+        }
+        return 1;
+    }
+    return 0;
+}
+
+static char *output_fields[] = {
+    "time",
+    "model",
+    "id",
+    "battery",
+    "channel",
+    "temperature_C",
+    "humidity",
+    NULL
+};
+
+r_device nexus = {
+    .name           = "Nexus Temperature & Humidity Sensor",
+    .modulation     = OOK_PULSE_PPM_RAW,
+    .short_limit    = 1744,
+    .long_limit     = 3500,
+    .reset_limit    = 5000,
+    .json_callback  = &nexus_callback,
+    .disabled       = 0,
+    .demod_arg      = 0,
+    .fields         = output_fields
+};