introduce functionality to decode the Oregon Scientific SL109H Remote…

… Thermal Hygro Sensor (merbanan#368)
kissandr · May 20, 2016 · ba20073 · ba20073
1 parent 579187c
commit ba20073
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Showing 6 changed files with 165 additions and 3 deletions.
diff --git a/README.md b/README.md
@@ -122,6 +122,7 @@ Supported devices:
         [50] Proove
         [51] Bresser Thermo-/Hygro-Sensor 3CH
 	[52] Springfield PreciseTemp Temperature and Soil Moisture
+    [53] Oregon Scientific SL109H Temperature & Humidity Sensor
 ```
 
 

diff --git a/include/rtl_433.h b/include/rtl_433.h
@@ -35,7 +35,7 @@
 #define DEFAULT_LEVEL_LIMIT     8000		// Theoretical high level at I/Q saturation is 128x128 = 16384 (above is ripple)
 #define MINIMAL_BUF_LENGTH      512
 #define MAXIMAL_BUF_LENGTH      (256 * 16384)
-#define MAX_PROTOCOLS           52
+#define MAX_PROTOCOLS           53
 #define SIGNAL_GRABBER_BUFFER   (12 * DEFAULT_BUF_LENGTH)
 
 /* Supported modulation types */

diff --git a/include/rtl_433_devices.h b/include/rtl_433_devices.h
@@ -55,7 +55,8 @@
 		DECL(oregon_scientific_v1) \
 		DECL(proove) \
 		DECL(bresser_3ch) \
-		DECL(springfield)
+		DECL(springfield) \
+		DECL(oregon_scientific_sl109h)
 
 typedef struct {
 	char name[256];

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
@@ -71,6 +71,7 @@ add_executable(rtl_433
 	devices/quhwa.c
 	devices/proove.c
 	devices/bresser_3ch.c
+	devices/oregon_scientific_sl109h.c
 
 )
 

diff --git a/src/Makefile.am b/src/Makefile.am
@@ -56,6 +56,7 @@ rtl_433_SOURCES      = baseband.c \
                        devices/s3318p.c \
                        devices/akhan_100F14.c \
                        devices/proove.c \
-                       devices/bresser_3ch.c
+                       devices/bresser_3ch.c \
+                       devices/oregon_scientific_sl109h.c
 
 rtl_433_LDADD        = $(LIBRTLSDR) $(LIBM)
diff --git a/src/devices/oregon_scientific_sl109h.c b/src/devices/oregon_scientific_sl109h.c
@@ -0,0 +1,158 @@
+//some hints from http://www.osengr.org/WxShield/Downloads/OregonScientific-RF-Protocols-II.pdf
+
+#include "rtl_433.h"
+#include "util.h"
+
+#define SL109H_MESSAGE_LENGTH 38
+#define CHECKSUM_BYTE_COUNT 4
+#define CHECKSUM_START_POSITION 6
+#define HUMIDITY_START_POSITION 6
+#define HUMIDITY_BIT_COUNT 8
+#define TEMPERATURE_START_POSITION 14
+#define TEMPERATURE_BIT_COUNT 12
+#define ID_START_POSITION 30
+
+static uint8_t calculate_humidity(bitbuffer_t *bitbuffer, unsigned row_index)
+{
+    int units_digit, tens_digit;
+
+    uint8_t out[1] = {0};
+    bitbuffer_extract_bytes(bitbuffer, row_index, HUMIDITY_START_POSITION, out, HUMIDITY_BIT_COUNT);
+
+    units_digit = out[0] & 0x0f;
+
+    tens_digit = (out[0] & 0xf0) >> 4;
+
+    return 10 * tens_digit + units_digit;
+}
+
+static int calculate_centigrade_decidegrees(bitbuffer_t *bitbuffer, unsigned row_index)
+{
+    int decidegrees = 0;
+
+    uint8_t out[2] = {0};
+    bitbuffer_extract_bytes(bitbuffer, row_index, TEMPERATURE_START_POSITION, out, TEMPERATURE_BIT_COUNT);
+
+    if(out[0] & 0x80) decidegrees = (~decidegrees << TEMPERATURE_BIT_COUNT);
+
+    decidegrees |= (out[0] << 4) | ((out[1] & 0xf0) >> 4);
+
+    return decidegrees;
+}
+
+static uint8_t get_channel_bits(uint8_t first_byte)
+{
+    return (first_byte & 0x0c) >> 2;
+}
+static int calculate_channel(uint8_t channel_bits)
+{
+    return (channel_bits % 3) ? channel_bits : 3;
+}
+
+//rolling code: changes when thermometer reset button is pushed/battery is changed
+static uint8_t get_id(bitbuffer_t *bitbuffer, unsigned row_index)
+{
+    uint8_t out[1] = {0};
+    bitbuffer_extract_bytes(bitbuffer, row_index, ID_START_POSITION, out, SL109H_MESSAGE_LENGTH - ID_START_POSITION);
+
+    return out[0];
+}
+
+//there may be more specific information here; not currently certain what information is encoded here
+static int get_status(uint8_t fourth_byte)
+{
+    return (fourth_byte & 0x3C) >> 2;
+}
+
+static int calculate_checksum(bitbuffer_t *bitbuffer, unsigned row_index, int channel)
+{
+    uint8_t calculated_checksum, actual_checksum;
+    uint8_t sum = 0;
+    int  actual_expected_comparison;
+
+    uint8_t out[CHECKSUM_BYTE_COUNT] = {0};
+    bitbuffer_extract_bytes(bitbuffer, row_index, CHECKSUM_START_POSITION, out, SL109H_MESSAGE_LENGTH - CHECKSUM_START_POSITION);
+
+    for(int i = 0; i < CHECKSUM_BYTE_COUNT; i++) sum += (out[i] & 0x0f) + (out[i] >> 4);
+
+    calculated_checksum = ((sum + channel) % 16);
+    actual_checksum     = bitbuffer->bb[row_index][0] >> 4;
+    actual_expected_comparison = (calculated_checksum == actual_checksum);
+
+    if(debug_output & !actual_expected_comparison) {
+        fprintf(stderr, "Checksum error in Oregon Scientific SL109H message.  Expected: %01x  Calculated: %01x\n", actual_checksum, calculated_checksum);
+        fprintf(stderr, "Message: ");
+        bitbuffer_print(bitbuffer);
+    }
+
+    return actual_expected_comparison;
+}
+
+
+static int oregon_scientific_callback_sl109h(bitbuffer_t *bitbuffer)
+{
+    data_t *data;
+    uint8_t *msg;
+    uint8_t channel_bits;
+
+    float temp_c;
+    uint8_t humidity;
+    int channel;
+    uint8_t id;
+    int status;
+    char time_str[LOCAL_TIME_BUFLEN];
+
+    for(int row_index = 0; row_index < bitbuffer->num_rows; row_index++) {
+        msg = bitbuffer->bb[row_index];
+
+        channel_bits = get_channel_bits(msg[0]);
+
+        if( !((bitbuffer->bits_per_row[row_index] == SL109H_MESSAGE_LENGTH)
+              && calculate_checksum(bitbuffer, row_index, channel_bits)) ) continue;
+
+        local_time_str(0, time_str);
+
+        temp_c = calculate_centigrade_decidegrees(bitbuffer, row_index) / 10.0;
+
+        humidity = calculate_humidity(bitbuffer, row_index);
+
+        id = get_id(bitbuffer, row_index);
+
+        channel = calculate_channel(channel_bits);
+
+        status = get_status(msg[3]);
+
+        data = data_make("time",          "",           DATA_STRING,                         time_str,
+                         "temperature_C", "Celcius",	DATA_FORMAT, "%.02f C", DATA_DOUBLE, temp_c,
+                         "humidity",      "Humidity",	DATA_FORMAT, "%u %%",   DATA_INT,    humidity,
+                         "channel",       "Channel",                            DATA_INT,    channel,
+                         "id",            "Id",                                 DATA_INT,    id,
+                         "status",        "Status",                             DATA_INT,    status,
+                         NULL);
+        data_acquired_handler(data);
+    }
+
+    return bitbuffer->num_rows;
+}
+
+static char *output_fields[] = {
+    "time",
+    "id",
+    "channel",
+    "status",
+    "temperature_C",
+    "humidity",
+    NULL
+};
+
+r_device oregon_scientific_sl109h = {
+    .name           = "Oregon Scientific SL109H Remote Thermal Hygro Sensor",
+    .modulation     = OOK_PULSE_PPM_RAW,
+    .short_limit    = 2800/*760*/,
+    .long_limit     = 4400/*1050*/,
+    .reset_limit    = 8000/*2240*/,
+    .json_callback  = &oregon_scientific_callback_sl109h,
+    .disabled       = 0,
+    .demod_arg      = 0,
+    .fields         = output_fields
+};