Merge pull request #99 from simonhyde/Implement_FineOffset

Implement FineOffset WH2/ClimeMet CM9088

RFLink/7_Utils.cpp

@@ -48,6 +48,14 @@ void reflect_nibbles(uint8_t message[], unsigned num_bytes)
     }
 }
 
+void invert_bytes(uint8_t message[], unsigned num_bytes)
+{
+    for (unsigned i = 0; i < num_bytes; ++i)
+    {
+        message[i] = ~message[i];
+    }
+}
+
 unsigned extract_nibbles_4b1s(uint8_t *message, unsigned offset_bits, unsigned num_bits, uint8_t *dst)
 {
     unsigned ret = 0;
@@ -378,9 +386,9 @@ inline bool value_between(uint32_t value, uint32_t min, uint32_t max)
     return (value > min && value < max);
 }
 
-bool decode_pwm(uint8_t frame[], uint8_t expectedBitCount, uint16_t const pulses[], const int pulsesCount, int pulseIndex, uint16_t shortPulseMinDuration, uint16_t shortPulseMaxDuration, uint16_t longPulseMinDuration, uint16_t longPulseMaxDuration)
+bool decode_pwm(uint8_t frame[], uint8_t expectedBitCount, uint16_t const pulses[], const int pulsesCount, int pulseIndex, uint16_t shortPulseMinDuration, uint16_t shortPulseMaxDuration, uint16_t longPulseMinDuration, uint16_t longPulseMaxDuration, uint8_t bitOffset)
 {
-    if (pulseIndex + expectedBitCount * 2 > pulsesCount)
+    if (pulseIndex + (expectedBitCount - 1) * 2  > pulsesCount)
     {
         #ifdef PWM_DEBUG
         Serial.print(F("PWM: Not enough pulses: pulseIndex = "));
@@ -397,8 +405,9 @@ bool decode_pwm(uint8_t frame[], uint8_t expectedBitCount, uint16_t const pulses
 
     const uint8_t bitsPerByte = 8;
     //const uint8_t expectedByteCount = expectedBitCount / bitsPerByte;
+    const uint8_t endBitCount = expectedBitCount + bitOffset;
 
-    for(int8_t bitIndex = 0; bitIndex < expectedBitCount; bitIndex++)
+    for(uint8_t bitIndex = bitOffset; bitIndex < endBitCount; bitIndex++)
     {
         int currentFrameByteIndex = bitIndex / bitsPerByte;
         uint16_t bitDuration = pulses[pulseIndex];

RFLink/7_Utils.h

@@ -63,6 +63,12 @@ uint8_t reflect4(uint8_t x);
 /// @param num_bytes number of bytes to reflect
 void reflect_nibbles(uint8_t message[], unsigned num_bytes);
 
+/// Invert each bit in each byte of a number of bytes.
+///
+/// @param message bytes of message data
+/// @param num_bytes number of bytes to invert
+void invert_bytes(uint8_t message[], unsigned num_bytes);
+
 /// Unstuff nibbles with 1-bit separator (4B1S) to bytes, returns number of successfully unstuffed nibbles.
 ///
 /// @param message bytes of message data
@@ -211,10 +217,12 @@ inline bool value_between(uint32_t value, uint32_t min, uint32_t max);
  *  @param pulses                 the pulses to decode
  *  @param pulsesCount            the numnber of items inside @pulses
  *  @param pulseIndex             the index of the first pulse to be decoded
- *  @param shortPulseMinDuration  the minimum duration of a half bit
- *  @param shortPulseMaxDuration  the maximum duration of a half bit
- *  @param longPulseMinDuration   the minimum duration of a half bit
- *  @param longPulseMaxDuration   the maximum duration of a half bit
+ *  @param shortPulseMinDuration  the minimum duration of a short (low) bit
+ *  @param shortPulseMaxDuration  the maximum duration of a short (low) bit
+ *  @param longPulseMinDuration   the minimum duration of a long (high) bit
+ *  @param longPulseMaxDuration   the maximum duration of a long (high) bit
+ *  @param bitOffset              offset (in bits) in output buffer to read first bit into
+ *  @param 
  *  @return true if pulses could be decoded, giving enough bits, false if not or pulses were not of valid lengths
 
     The PWM encoding uses pair of pulses like this:
@@ -225,18 +233,26 @@ inline bool value_between(uint32_t value, uint32_t min, uint32_t max);
     So, for instance, we would receive this: ----__----__----__--____
     This gives 4 pairs, hence 4 bits, long/short, long/short, long/short, short/long 
 
+    Note that for efficiency reasons, this method does not consider the second pulse of the pair and thus does not test
+    it for duration validity.
+    
+    Because this method actually doesn't check the length of the second pulse of a PWM, it can also be used for devices
+    which have a constant-length gap between the data pulse and the next one, ie:
+
+    Long then gap  : ----___
+    Short then gap : --___
+
     This method uses the following truth table
 
        Pair      |  Value
      ------------+--------  
       long/short |    1
       short/long |    0
+      long/gap   |    1
+      short/gap  |    0
 
     If you need the opposite, simply use the ~ operator on the frame bytes
 
-    Note that for efficiency reasons, this method does not consider the second pulse of the pair and thus does not test
-    it for duration validity.
-    
     Bits are placed in the frame in the order they appear, ie MSB first. To illustrate, consider the following set of pulses:
 
     --_-__--_--_--_--_-__--_--_-__-__--_--_--_-__-__-__--_-__--_--_--_-__-__
@@ -255,7 +271,7 @@ inline bool value_between(uint32_t value, uint32_t min, uint32_t max);
     But because the ESP32 is a little endian architecture, the bytes will be reversed two by two (0 - 3, 1 - 2)
     Using ntohs or ntohl from <netinet/in.h> is thus recommended in that case
 */
-bool decode_pwm(uint8_t frame[], uint8_t expectedBitCount, uint16_t const pulses[], const int pulsesCount, int pulseIndex, uint16_t shortPulseMinDuration, uint16_t shortPulseMaxDuration, uint16_t longPulseMinDuration, uint16_t longPulseMaxDuration);
+bool decode_pwm(uint8_t frame[], uint8_t expectedBitCount, uint16_t const pulses[], const int pulsesCount, int pulseIndex, uint16_t shortPulseMinDuration, uint16_t shortPulseMaxDuration, uint16_t longPulseMinDuration, uint16_t longPulseMaxDuration, uint8_t bitOffset = 0);
 
 /**
  *  Decodes the pulses as a Manchester encoded series of pulses

RFLink/Plugins/Plugin_050.c

@@ -0,0 +1,87 @@
+/**
+Fine Offset Electronics WH2 Temperature/Humidity sensor protocol,
+also Agimex Rosenborg 66796 (sold in Denmark), collides with WH5,
+also ClimeMET CM9088 (Sold in UK),
+also TFA Dostmann/Wertheim 30.3157 (Temperature only!) (sold in Germany).
+
+The sensor sends two identical packages of 48 bits each ~48s. The bits are PWM modulated with On Off Keying.
+
+The data is grouped in 6 bytes / 12 nibbles.
+
+    [pre] [pre] [type] [id] [id] [temp] [temp] [temp] [humi] [humi] [crc] [crc]
+
+There is an extra, unidentified 7th byte in WH2A packages.
+
+- pre is always 0xFF
+- type is always 0x4 (may be different for different sensor type?)
+- id is a random id that is generated when the sensor starts
+- temp is 12 bit signed magnitude scaled by 10 celsius
+- humi is 8 bit relative humidity percentage
+
+Based on 
+http://lucsmall.com/2012/04/29/weather-station-hacking-part-2/
+and
+https://github.com/lucsmall/WH2-Weather-Sensor-Library-for-Arduino
+
+Comment detailing protocol from rtl_433 project.
+*/
+#define FINEOFFSET_PLUGIN_ID 050
+#define PLUGIN_DESC_050 "FineOffset Temp/Humidity sensors"
+
+#ifdef PLUGIN_050
+#include "../4_Display.h"
+#include "../1_Radio.h"
+#include "../7_Utils.h"
+
+#define PLUGIN_050_ID "FineOffset"
+
+#define FINEOFFSET_PULSE_COUNT 96
+
+#ifdef PLUGIN_050_DEBUG
+#define SerialDebugActivated
+#endif
+
+boolean Plugin_050(byte function, const char *string)
+{
+    if (RawSignal.Number == FINEOFFSET_PULSE_COUNT) 
+    {
+        const int CM_LongLowMinDuration = 1200 / RawSignal.Multiply;
+        const int CM_LongLowMaxDuration = 1600 / RawSignal.Multiply;
+        const int CM_ShortHighMinDuration = 300 / RawSignal.Multiply;
+        const int CM_ShortHighMaxDuration = 600 / RawSignal.Multiply;
+        byte data[6] = {0, 0, 0, 0, 0, 0};
+        //Skip the first bit as the lengths tend to vary...
+        if(!decode_pwm(data, 47, RawSignal.Pulses,RawSignal.Number, 3, CM_ShortHighMinDuration, CM_ShortHighMaxDuration, CM_LongLowMinDuration, CM_LongLowMaxDuration, 1))
+            return false;
+        invert_bytes(data, 6);
+        byte calculated_crc = crc8(data + 1, 4, 0x31, 0);
+#ifdef PLUGIN_050_DEBUG
+        const size_t buflen = sizeof(PLUGIN_050_ID ": packet = ") + 32;
+        char printbuf[buflen];
+        snprintf(printbuf, buflen, "%s%02x%02x%02x%02x%02x%02x, CRC=%02x", PLUGIN_088_ID ": packet = ", data[0], data[1], data[2], data[3],data[4], data[5], calculated_crc);
+        SerialDebugPrintln(printbuf);
+#endif
+        if(calculated_crc != data[5])
+        {
+#ifdef PLUGIN_050_DEBUG
+            SerialDebugPrintln(PLUGIN_050_ID ": CRC Check Failed");
+#endif
+            return false;
+        }
+
+        uint16_t unitid = (data[1] << 4) | (data[2] >> 4);
+        uint16_t temperature = ((data[2] & 0xF) << 8) | data[3];
+        //MSB of 12-bit number actually indicates sign, this isn't standard two's complement
+        if(temperature & 0x800)
+            temperature = - (temperature & 0x7FF);
+        byte humidity = data[4];
+        display_Header();
+        display_Name(PLUGIN_050_ID);
+        display_IDn(unitid, 4);  // unit id
+        display_TEMP(temperature); 
+        display_HUM(humidity); 
+        display_Footer();
+    }
+    return false;
+}
+#endif

RFLink/Plugins/_Plugin_Config_01.h

@@ -64,6 +64,7 @@
 #define PLUGIN_047 // Auriol v4
 #define PLUGIN_048 // Oregon Weather
 #define PLUGIN_049 // Lacrosse TX141
+#define PLUGIN_050 // FineOffset WH2 / ClimeMet CM9088 Temperature/Humidity
 // -------------------
 // Motion Sensors, include when needed
 // -------------------