v2.5

- Add support for BMx820 sensor (temperature only).
- Modify former "light sensor" keypad menu to not only show measured lux level from a light sensor, but also current ambient temperature as measured by a connected temperature sensor. Rename menu to "Sensors" accordingly.
- Add temperature offset value. User can program an offset that will be added to the measured temperature for compensating sensor inaccuracies or suboptimal sensor placement. In order to calibrate the offset, use the keypad menu "SENSORS" since the temperature shown there is not rounded (unlike what is shown on a speedo display if it has less than three digits).

Software/src/sensors.cpp

@@ -7,7 +7,7 @@
  * Sensor Class: Temperature and Light Sensor handling
  *
  * This is designed for 
- * - MCP9808-based temperature sensors,
+ * - MCP9808, BMx820 temperature sensors,
  * - BH1750, TSL2561 and VEML7700/VEML6030 light sensors.
  * -------------------------------------------------------------------
  * License: MIT
@@ -45,15 +45,20 @@ static void defaultDelay(unsigned int mydelay)
     delay(mydelay);
 }
 
+void tcSensor::prepareRead(uint16_t regno)
+{
+    Wire.beginTransmission(_address);
+    Wire.write((uint8_t)(regno));
+    Wire.endTransmission(false);
+}
+
 uint16_t tcSensor::read16(uint16_t regno, bool LSBfirst)
 {
     uint16_t value = 0;
     size_t i2clen = 0;
 
     if(regno <= 0xff) {
-        Wire.beginTransmission(_address);
-        Wire.write((uint8_t)(regno));
-        Wire.endTransmission(false);
+        prepareRead(regno);
     }
 
     i2clen = Wire.requestFrom(_address, (uint8_t)2);
@@ -70,13 +75,29 @@ uint16_t tcSensor::read16(uint16_t regno, bool LSBfirst)
     return value;
 }
 
+uint32_t tcSensor::read24(uint16_t regno)
+{
+    uint32_t value = 0;
+    size_t i2clen = 0;
+
+    prepareRead(regno);
+
+    i2clen = Wire.requestFrom(_address, (uint8_t)3);
+
+    if(i2clen > 0) {
+        value = Wire.read() << 16;
+        value |= (Wire.read() << 8);
+        value |= Wire.read();
+    }
+
+    return value;
+}
+
 uint8_t tcSensor::read8(uint16_t regno)
 {
     uint16_t value = 0;
 
-    Wire.beginTransmission(_address);
-    Wire.write((uint8_t)(regno));
-    Wire.endTransmission(false);
+    prepareRead(regno);
 
     Wire.requestFrom(_address, (uint8_t)1);
 
@@ -112,7 +133,7 @@ void tcSensor::write8(uint16_t regno, uint8_t value)
 /*****************************************************************
  * tempSensor Class
  * 
- * Supports MCP9808-based temperature sensors
+ * Supports MCP9808 and BMx820 temperature sensors
  * 
  ****************************************************************/
 
@@ -145,6 +166,17 @@ void tcSensor::write8(uint16_t regno, uint8_t value)
 #define TC_TEMP_RES_MCP9808 2
 static const uint16_t wakeDelayMCP9808[4] = { 30, 65, 130, 250 };
 
+#define BMx280_REG_DIG_T1 0x88
+#define BMx280_REG_DIG_T2 0x8a
+#define BMx280_REG_DIG_T3 0x8c
+#define BMx280_REG_ID     0xd0
+#define BME280_REG_RESET  0xe0
+#define BMx820_REG_CTRLH  0xf2
+#define BMx280_REG_STATUS 0xf3
+#define BMx820_REG_CTRLM  0xf4
+#define BMx820_REG_CONF   0xf5
+#define BMx820_REG_TEMP   0xfa
+
 
 // Store i2c address
 tempSensor::tempSensor(int numTypes, uint8_t addrArr[])
@@ -160,6 +192,7 @@ tempSensor::tempSensor(int numTypes, uint8_t addrArr[])
 bool tempSensor::begin()
 {
     bool foundSt = false;
+    uint8_t temp, timeOut = 20;
 
     _customDelayFunc = defaultDelay;
 
@@ -177,7 +210,15 @@ bool tempSensor::begin()
                 #endif
             }
             break;
-        /*...*/
+        case BMx820:
+            temp = read8(BMx280_REG_ID);
+            if(temp == 0x60 || temp == 0x58) {
+                foundSt = true;
+                #ifdef TC_DBG
+                Serial.println("tempSensor: Detected BMx820 temperature sensor");
+                #endif
+            }
+            break;
         }
 
         if(foundSt) {
@@ -187,13 +228,45 @@ bool tempSensor::begin()
     }
 
     switch(_st) {
+
     case MCP9808:
         // Write config register
         write16(MCP9808_REG_CONFIG, 0x0);
 
         // Set resolution
         write8(MCP9808_REG_RESOLUTION, TC_TEMP_RES_MCP9808 & 0x03);
         break;
+
+    case BMx820:
+        // Reset
+        write8(BME280_REG_RESET, 0xb6);
+        (*_customDelayFunc)(10);
+
+        // Wait for sensor to copy its calib data
+        do {
+            temp = read8(BMx280_REG_STATUS);
+            (*_customDelayFunc)(10);
+        } while((temp & 1) && --timeOut);
+
+        // read relevant calib data
+        _BMx280_CD_T1 = read16(BMx280_REG_DIG_T1, true);
+        _BMx280_CD_T2 = (int32_t)((int16_t)read16(BMx280_REG_DIG_T2, true));
+        _BMx280_CD_T3 = (int32_t)((int16_t)read16(BMx280_REG_DIG_T3, true));
+        #ifdef TC_DBG
+        Serial.println("BMx820 calib values");
+        Serial.println(_BMx280_CD_T1);
+        Serial.println(_BMx280_CD_T2);
+        Serial.println(_BMx280_CD_T3);
+        #endif
+
+        // setup sensor parameters
+        write8(BMx820_REG_CTRLM, 0x20);  // Temp OSx1; Pres skipped; "sleep mode"
+        write8(BMx820_REG_CTRLH, 0x00);  // Hum skipped
+        write8(BMx820_REG_CONF,  0xa0);  // t_sb 1000ms; filter off, SPI3w off
+
+        write8(BMx820_REG_CTRLM, 0x23);  // Temp OSx1; Pres skipped; "normal mode"
+        break;
+
     default:
         return false;
     }
@@ -224,27 +297,39 @@ void tempSensor::off()
 double tempSensor::readTemp(bool celsius)
 {
     double temp = NAN;
+    uint16_t t;
 
     switch(_st) {
     case MCP9808:
-        uint16_t t = read16(MCP9808_REG_AMBIENT_TEMP);
+        t = read16(MCP9808_REG_AMBIENT_TEMP);
 
         if(t != 0xffff) {
             temp = ((double)(t & 0x0fff)) / 16.0;
             if(t & 0x1000) temp = 256.0 - temp;
-            if(!celsius) temp = temp * 9.0 / 5.0 + 32.0;
         }
         break;
+    case BMx820:
+        temp = BMx280_CalcTemp(read24(BMx820_REG_TEMP));
+        break;
     }
 
+    if(!celsius && !isnan(temp)) temp = temp * 9.0 / 5.0 + 32.0;
+
+    temp += _userOffset;
+
     #ifdef TC_DBG
     Serial.print("Read temp: ");
     Serial.println(temp);
-    #endif
+    #endif   
 
     return temp;
 }
 
+void tempSensor::setOffset(double myOffs)
+{
+    _userOffset = myOffs;
+}
+
 // Private functions ###########################################################
 
 void tempSensor::onoff(bool shutDown)
@@ -277,19 +362,33 @@ void tempSensor::onoff(bool shutDown)
     }
 }
 
+double tempSensor::BMx280_CalcTemp(uint32_t ival)
+{
+    int32_t var1, var2;
+
+    if(ival == 0x800000) return NAN;
+
+    ival >>= 4;
+
+    var1 = ((((ival >> 3) - (_BMx280_CD_T1 << 1))) * _BMx280_CD_T2) / 2048;
+    var2 = (ival >> 4) - _BMx280_CD_T1;
+    var2 = (((var2 * var2) / 4096) * _BMx280_CD_T3) / 16384;
+
+    return (double)(((var1 + var2) * 5 + 128) / 256) / 100.0;
+}
 
 #endif // TC_HAVETEMP
 
 
 /*****************************************************************
  * lightSensor Class
  * 
- * Supports TSL2561, BH1750, VEML7700 light sensors
+ * Supports TSL2561, BH1750, VEML7700/6030 light sensors
  * 
  * Sensors are set for indoor conditions and might overflow (in 
  * which case -1 is returned) or report bad lux values outdoors.
  * For TSL2561 and BH1750, their settings can be changed by 
- * #defines below. VEML7700 auto-adjusts.
+ * #defines below. VEML7700/6030 auto-adjust.
  * 
  ****************************************************************/
 
@@ -677,7 +776,7 @@ uint32_t lightSensor::TSL2561CalcLux(uint8_t iGain, uint8_t tInt, uint32_t ch0,
 
     ratio = (ratio1 + 1) >> 1;
 
-    if((ratio >= 0) && (ratio <= TSL2561_K1T))
+    if(ratio <= TSL2561_K1T)
         { b = TSL2561_B1T; m = TSL2561_M1T; }
     else if (ratio <= TSL2561_K2T)
         { b = TSL2561_B2T; m = TSL2561_M2T; }
@@ -691,7 +790,7 @@ uint32_t lightSensor::TSL2561CalcLux(uint8_t iGain, uint8_t tInt, uint32_t ch0,
         { b = TSL2561_B6T; m = TSL2561_M6T; }
     else if(ratio <= TSL2561_K7T)
         { b = TSL2561_B7T; m = TSL2561_M7T; }
-    else if(ratio > TSL2561_K8T)
+    else //if(ratio > TSL2561_K8T)
         { b = TSL2561_B8T; m = TSL2561_M8T; }
 
     temp = ((channel0 * b) - (channel1 * m));

Software/src/sensors.h

@@ -40,9 +40,11 @@
 class tcSensor {
 
     protected:
-
+
+        void     prepareRead(uint16_t regno);
         uint16_t read16(uint16_t regno, bool LSBfirst = false);
         uint8_t  read8(uint16_t regno);
+        uint32_t read24(uint16_t regno);
         void     write16(uint16_t regno, uint16_t value, bool LSBfirst = false);
         void     write8(uint16_t regno, uint8_t value);
 
@@ -54,7 +56,8 @@ class tcSensor {
 #ifdef TC_HAVETEMP    // -----------------------------------------
 
 enum {
-    MCP9808 = 0
+    MCP9808 = 0,
+    BMx820
 };
 
 class tempSensor : tcSensor {
@@ -71,14 +74,24 @@ class tempSensor : tcSensor {
         void off();
         double readTemp(bool celsius = true);
 
+        void setOffset(double myOffs);
+
     private:
 
         int     _numTypes = 0;
         uint8_t _addrArr[4*2];    // up to 4 sensor types fit here
         int8_t  _st = -1;
 
+        double  _userOffset = 0.0;
+
+        uint32_t _BMx280_CD_T1;
+        int32_t  _BMx280_CD_T2;
+        int32_t  _BMx280_CD_T3;
+
         void onoff(bool shutDown);
 
+        double BMx280_CalcTemp(uint32_t ival);
+
         // Ptr to custom delay function
         void (*_customDelayFunc)(unsigned int) = NULL;
 };

Software/src/speeddisplay.cpp

@@ -304,8 +304,8 @@ static struct dispConf displays[SP_NUM_TYPES] = {
   { false, 3, 4, 0, 0, 4, 0,   5, 0, 0x2080, 8, 4, 0, { 1, 2, 3, 4 }, font144segGrove },  // SP_GROVE_4DIG14 (right)
   { false, 1, 2, 0, 0, 2, 0,   5, 0, 0x2080, 8, 4, 0, { 1, 2, 3, 4 }, font144segGrove },  // SP_GROVE_4DIG14 (left)
 #ifdef TWPRIVATE
-  { false, 0, 1, 0, 0, 1, 0, 255, 0,      0, 8, 2, 0, { 0, 1 },       font14segGeneric }, // TW Custom (wallclock)
-  { true,  0, 1, 0, 0, 1, 0,   2, 0, 0x0002, 8, 2, 0, { 0, 1 },       font7segGeneric },  // TW Custom (speedo replica)
+  { false, 0, 1, 0, 0, 1, 0, 255, 0,      0, 8, 2, 0, { 0, 1 },       font14segGeneric }, // TW Custom (wall clock)
+  { true,  0, 1, 0, 0, 1, 0, 255, 0,      0, 8, 2, 0, { 0, 1 },       font7segGeneric },  // TW Custom (speedo replica)
 #endif
 // .... for testing only:
 //{ true,  7, 7, 0, 8, 7, 8, 255, 0,      0, 8, 2, 1, { 7 },          font7segGeneric },  // SP_TCD_TEST7

Software/src/speeddisplay.h

@@ -51,8 +51,8 @@
 //
 // The display's i2c slave address is 0x70 (defined in tc_time.h).
 //
-enum dispTypes : int {
-    SP_CIRCSETUP,     // Original CircuitSetup.us speedo                        [yet to be designed]
+enum dispTypes : uint8_t {
+    SP_CIRCSETUP = 0, // Original CircuitSetup.us speedo                        [yet to be designed]
     SP_ADAF_7x4,      // Adafruit 0.56" 4 digits, 7-segment (7x4) (ADA-878)
     SP_ADAF_7x4L,     // " " " (left-aligned)
     SP_ADAF_B7x4,     // Adafruit 1.2" 4 digits, 7-segment (7x4) (ADA-1270)
@@ -125,7 +125,7 @@ class speedDisplay {
         bool    _nightmode = false;
         int     _oldnm = -1;
 
-        int      _dispType;
+        uint8_t  _dispType;
         bool     _is7seg;         //      7- or 14-segment-display?
         uint8_t  _speed_pos10;    //      Speed's 10s position in 16bit buffer
         uint8_t  _speed_pos01;    //      Speed's 1s position in 16bit buffer

Software/src/tc_font.h

@@ -118,7 +118,7 @@ static const uint16_t alphaChars[128] = {
     0b0000000011101110,  // Y
     0b0000110000001001,  // Z
     0b0000000000111001,  // [
-    0b0010000100000000,  //
+    0b0010000100000000,  // \
     0b0000000000001111,  // ]
     0b0000110000000011,  // ^
     0b0000000000001000,  // _

Software/src/tc_global.h

@@ -29,11 +29,11 @@
 // These must not contain any characters other than
 // '0'-'9', 'A'-'Z', '(', ')', '.', '_', '-' or space
 #ifndef IS_ACAR_DISPLAY
-#define TC_VERSION "V2.4.0"           // 13 chars max
-#define TC_VERSION_EXTRA "NOV232022"  // 13 chars max
+#define TC_VERSION "V2.5.0"           // 13 chars max
+#define TC_VERSION_EXTRA "DEC022022"  // 13 chars max
 #else   // A-Car
-#define TC_VERSION "V2.4.0_A-CAR"     // 12 chars max
-#define TC_VERSION_EXTRA "11232022"   // 12 chars max
+#define TC_VERSION "V2.5.0_A-CAR"     // 12 chars max
+#define TC_VERSION_EXTRA "12022022"   // 12 chars max
 #endif
 
 //#define TC_DBG            // debug output on Serial
@@ -53,15 +53,16 @@
 #define SP_NUM_TYPES    10  // Number of speedo display types supported
 #define SP_MIN_TYPE     1   // Change to 0 when CircuitSetup speedo prop exists
 
-// Uncomment for support of a temperature sensor (MCP9808-based) connected 
-// via i2c (0x18). Will be used to display ambient temperature on speedometer 
+// Uncomment for support of a temperature sensor (MCP9808, BMx820) connected 
+// via i2c. Will be used to display ambient temperature on speedometer 
 // display when idle. GPS speed has higher priority, ie if GPS speed is 
 // enabled in Config Portal, temperature will not be shown.
 #define TC_HAVETEMP
 
-// Uncomment for support of s light sensor (TLS2561, BH1750, or VEML7700) 
-// connected via i2c. Used for night-mode-switching. VEML7700 and GPS cannot 
-// be present at the same time since they share the same i2c slave address.
+// Uncomment for support of a light sensor (TLS2561, BH1750, VEML7700 or
+// VEML6030) connected via i2c. Used for night-mode-switching. VEML7700  
+// and GPS cannot be present at the same time since they share the same 
+// i2c slave address. VEML6030 needs to be set to 0x48 if GPS is present.
 //#define TC_HAVELIGHT
 
 // Fake Power Switch: