Add Support for Ecowitt WN34D and improve WN34L

merbanan · May 28, 2024 · 4d133bb · 4d133bb
1 parent 3339a4e
commit 4d133bb
Showing 1 changed file with 32 additions and 20 deletions.
diff --git a/src/devices/fineoffset_wn34.c b/src/devices/fineoffset_wn34.c
@@ -14,23 +14,26 @@
 /**
 Fine Offset Electronics WN34 Temperature Sensor.
 
-- also Ecowitt WN34S (soil), WN34L (water)
+- also Ecowitt WN34S (soil), WN34L (water), range is -40~60 °C (-40~140 °F)
+- also Ecowitt WN34D (water), range is -55~125 °C (-67~257 °F)
 - also Froggit DP150 (soil), DP35 (water)
 
 Preamble is aaaa aaaa, sync word is 2dd4.
 
 Packet layout:
 
-     0  1  2  3  4  5  6  7  8
-    YY II II II 0T TT BB XX AA
-    34 00 29 65 02 85 44 66 f3
+     0  1  2  3  4  5  6  7  8  9 10
+    YY II II II ST TT BB XX AA ZZ ZZ
+    34 00 29 65 02 85 44 66 f3 20 10
 
-- Y: 8 bit fixed sensor type 0x34
-- I: 24 bit device ID
-- T: 11 bit temperature, offset 40, scale 10
-- B: 7 bit battery level (unit of 20 mV)
-- X: 8 bit CRC
-- A: 8 bit checksum
+- Y:{8}  fixed sensor type 0x34
+- I:{24} device ID
+- S:{4}  sub type, 0 = WN34L, 0x4 = WN34D
+- T:{12} temperature, offset 40 (except WN34D), scale 10
+- B:{7}  battery level (unit of 20 mV)
+- X:{8}  bit CRC
+- A:{8}  bit checksum
+- Z:{13} trail byte, not used.
 
 */
 
@@ -40,6 +43,7 @@ static int fineoffset_wn34_decode(r_device *decoder, bitbuffer_t *bitbuffer)
     uint8_t const preamble[] = {0xAA, 0x2D, 0xD4};
     uint8_t b[9];
     unsigned bit_offset;
+    float temperature;
 
     bit_offset = bitbuffer_search(bitbuffer, 0, 0, preamble, sizeof(preamble) * 8) + sizeof(preamble) * 8;
     if (bit_offset + sizeof(b) * 8 > bitbuffer->bits_per_row[0]) {  // Did not find a big enough package
@@ -68,10 +72,16 @@ static int fineoffset_wn34_decode(r_device *decoder, bitbuffer_t *bitbuffer)
     }
 
     // Decode data
-    int id            = (b[1] << 16) | (b[2] << 8) | (b[3]);
-    int temp_raw      = (b[4] & 0x7) << 8 | b[5];
-    float temperature = (temp_raw - 400) * 0.1f;    // range -40.0-60.0 C
-    int battery_mv    = (b[6] & 0x7f) * 20;         // mV
+    int id          = (b[1] << 16) | (b[2] << 8) | (b[3]);
+    int temp_raw    = (int16_t)((b[4] & 0x0F) << 12 | b[5] << 4); // use sign extend
+    int sub_type    = (b[4] & 0xF0) >> 4;
+
+    if (sub_type == 4) // WN34D
+        temperature = (temp_raw >> 4) * 0.1f;    // scale by 10 only.
+    else // WN34L/WN34S ...
+        temperature = ((temp_raw >> 4) * 0.1f) - 40;    // scale by 10, offset 40
+
+    int battery_mv  = (b[6] & 0x7f) * 20;         // mV
 
     /*
      * A 5 bar battery indicator is shown in the Ecowitt WS View app.
@@ -97,12 +107,13 @@ static int fineoffset_wn34_decode(r_device *decoder, bitbuffer_t *bitbuffer)
 
     /* clang-format off */
     data = data_make(
-            "model",            "",             DATA_STRING, "Fineoffset-WN34",
-            "id",               "ID",           DATA_FORMAT, "%x", DATA_INT, id,
-            "battery_ok",       "Battery",      DATA_FORMAT, "%.1f", DATA_DOUBLE, battery_ok,
-            "battery_mV",       "Battery Voltage", DATA_FORMAT, "%d mV", DATA_INT, battery_mv,
-            "temperature_C",    "Temperature",  DATA_FORMAT, "%.1f C", DATA_DOUBLE, temperature,
-            "mic",              "Integrity",    DATA_STRING, "CRC",
+            "model",         "",                DATA_STRING, "Fineoffset-WN34",
+            "id",            "ID",              DATA_FORMAT, "%x",     DATA_INT,    id,
+            "subtype",       "Subtype",         DATA_INT,    sub_type,
+            "battery_ok",    "Battery",         DATA_FORMAT, "%.1f",   DATA_DOUBLE, battery_ok,
+            "battery_mV",    "Battery Voltage", DATA_FORMAT, "%d mV",  DATA_INT,    battery_mv,
+            "temperature_C", "Temperature",     DATA_FORMAT, "%.1f C", DATA_DOUBLE, temperature,
+            "mic",           "Integrity",       DATA_STRING, "CRC",
             NULL);
     /* clang-format on */
 
@@ -113,6 +124,7 @@ static int fineoffset_wn34_decode(r_device *decoder, bitbuffer_t *bitbuffer)
 static char const *const output_fields[] = {
         "model",
         "id",
+        "subtype",
         "battery_ok",
         "battery_mV",
         "temperature_C",