From 60657999e5096cac0b6e946a94c651bf810756df Mon Sep 17 00:00:00 2001
From: John Pochmara <127617714+jpochmara@users.noreply.github.com>
Date: Mon, 3 Feb 2025 10:36:48 -0800
Subject: [PATCH] Add rain start detection feature for WS90 sensor (#3183)

---
 src/devices/fineoffset_ws90.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/devices/fineoffset_ws90.c b/src/devices/fineoffset_ws90.c
index 422b0bfb8..f7bcebd76 100644
--- a/src/devices/fineoffset_ws90.c
+++ b/src/devices/fineoffset_ws90.c
@@ -50,11 +50,17 @@ Packet layout:
 - V = uv index, scale 10
 - U = unknown (bytes 14 and 15 appear to be fixed at 3f ff)
 - R = rain total (R3 << 8 | R4) * 0.1 mm
+- RS = rain start dection ((R1 & 0x10) >>4), 1 = raining, 0 = not raining
 - S = super cap voltage, unit of 0.1V, lower 6 bits, mask 0x3f
 - Z = Firmware version. 0x82 = 130 = 1.3.0
 - A = checksum
 - X = CRC
 
+Rain start info:
+Status 1 will be reset to 0 when:
+- Once the top is dry
+- After the amount of water on the top has remained unchanged for two hours.
+
 */
 
 static int fineoffset_ws90_decode(r_device *decoder, bitbuffer_t *bitbuffer)
@@ -106,6 +112,7 @@ static int fineoffset_ws90_decode(r_device *decoder, bitbuffer_t *bitbuffer)
     int wind_max    = ((b[7] & 0x40) << 2) | (b[12]);
     int uv_index    = (b[13]);
     int rain_raw    = (b[19] << 8 ) | (b[20]);
+    int rain_start  = (b[16] & 0x10) >> 4;
     int supercap_V  = (b[21] & 0x3f);
     int firmware    = b[29];
 
@@ -130,6 +137,7 @@ static int fineoffset_ws90_decode(r_device *decoder, bitbuffer_t *bitbuffer)
             "light_lux",        "Light",            DATA_COND, light_raw != 0xffff, DATA_FORMAT, "%.1f lux", DATA_DOUBLE, (double)light_lux,
             "flags",            "Flags",            DATA_FORMAT, "%02x", DATA_INT, flags,
             "rain_mm",          "Total Rain",       DATA_FORMAT, "%.1f mm", DATA_DOUBLE, rain_raw * 0.1f,
+            "rain_start",       "Rain Start",       DATA_INT, rain_start,
             "supercap_V",       "Supercap Voltage", DATA_COND, supercap_V != 0xff, DATA_FORMAT, "%.1f V", DATA_DOUBLE, supercap_V * 0.1f,
             "firmware",         "Firmware Version", DATA_INT, firmware,
             "data",             "Extra Data",       DATA_STRING, extra,
@@ -156,6 +164,7 @@ static char const *const output_fields[] = {
         "flags",
         "unknown",
         "rain_mm",
+        "rain_start",
         "supercap_V",
         "firmware",
         "data",