Diff: BME280.cpp

Revision:

2:4ed2f08d0eff

Parent:

1:d766e0ac711f

Child:

3:b3835216cc88

--- a/BME280.cpp	Sat Nov 07 12:05:49 2015 +0000
+++ b/BME280.cpp	Sat Nov 07 12:23:29 2015 +0000
@@ -47,7 +47,7 @@
 
 extern Serial ser;
 
-BME280::BME280(void) : m_pI2C(NULL), m_address(0x00), m_fine_temp(0x1F3E6), m_mode(MODE_SLEEP) {
+BME280::BME280(void) : m_pI2C(NULL), m_address(0x00), m_fine_temp(0x1F3E6), m_mode(MODE_SLEEP),m_bOk(false) {
     // initialized m_fine_temp to 25C
 }
 
@@ -56,12 +56,14 @@
 }
 
 bool BME280::init(I2C& i2c, uint8_t address) {
+    m_bOk = false;
     m_pI2C = &i2c;
     m_address = address<<1;
     m_fine_temp = 0x1F3E6;
     if (!reset()) return false;
     if (read_chip_id()!=0x60) return false;
     if (!read_calibration()) return false;
+    m_bOk = true;
     return true;
 }
 
@@ -140,19 +142,10 @@
 bool BME280::raw_data(int32_t& rawT, int32_t& rawP, int32_t& rawH) {
     if (m_pI2C==NULL) return false;
     uint8_t data[8];
-    uint8_t ok = 0x00;
-    m_pI2C->start();
-        ok = (ok<<1)|m_pI2C->write(m_address);
-        ok = (ok<<1)|m_pI2C->write(REG_PRESS_MSB);
-        m_pI2C->start();
-        ok = (ok<<1)|m_pI2C->write(m_address|1);
-        for (int i=0; i<7; i++) data[i] = m_pI2C->read(1);
-        data[7] = m_pI2C->read(0);
-    m_pI2C->stop();
-    if (ok!=0x7) {
-        rawT = rawP = rawH = 0x00;
+    if (!burst_read(data,8,REG_PRESS_MSB)) {
+        rawT = rawP = rawH = 0;
         return false;
-    }    
+    }
     rawP = (int32_t(data[0])<<12)|(int32_t(data[1])<<4)|(int32_t(data[2])>>4);
     rawT = (int32_t(data[3])<<12)|(int32_t(data[4])<<4)|(int32_t(data[5])>>4);
     rawH = (int32_t(data[6])<<8)|int32_t(data[7]);
@@ -174,19 +167,9 @@
 }
 
 bool BME280::read_calibration_lo(void) {
+    if (m_pI2C==NULL) return false;
     uint8_t data[VAL_CALIB00_25_SIZE];
-    if (m_pI2C==NULL) return false;
-    uint8_t ok = 0x00;
-    m_pI2C->start();
-        ok = (ok<<1)|m_pI2C->write(m_address);
-        ok = (ok<<1)|m_pI2C->write(REG_CALIB00_25_BASE);
-        m_pI2C->start();
-        ok = (ok<<1)|m_pI2C->write(m_address|1);
-        for (int n=0; n<VAL_CALIB00_25_SIZE-1; n++) data[n] = m_pI2C->read(1);
-        data[VAL_CALIB00_25_SIZE-1] = m_pI2C->read(0);
-    m_pI2C->stop();
-    if (ok!=0x7) return false;
-    
+    if (!burst_read(data,VAL_CALIB00_25_SIZE,REG_CALIB00_25_BASE)) return false;
     m_calib.dig_T1 = conv_u16(data,0,1);    // 0x88:89
     m_calib.dig_T2 = conv_s16(data,2,3);    // 0x8A:8B
     m_calib.dig_T3 = conv_s16(data,4,5);    // 0x8C:8D
@@ -205,19 +188,9 @@
 }
 
 bool BME280::read_calibration_hi(void) {
+    if (m_pI2C==NULL) return false;
     uint8_t data[VAL_CALIB26_41_SIZE];
-    if (m_pI2C==NULL) return false;
-    uint8_t ok = 0x00;
-    m_pI2C->start();
-        ok = (ok<<1)|m_pI2C->write(m_address);
-        ok = (ok<<1)|m_pI2C->write(REG_CALIB26_41_BASE);
-        m_pI2C->start();
-        ok = (ok<<1)|m_pI2C->write(m_address|1);
-        for (int n=0; n<VAL_CALIB26_41_SIZE-1; n++) data[n] = m_pI2C->read(1);
-        data[VAL_CALIB26_41_SIZE-1] = m_pI2C->read(0);
-    m_pI2C->stop();
-    if (ok!=0x7) return false;
-   
+    if (!burst_read(data,VAL_CALIB26_41_SIZE,REG_CALIB26_41_BASE)) return false;
     m_calib.dig_H2 = conv_s16(data,0,1);                                            // 0xE1:E2
     m_calib.dig_H3 = data[2];                                                       // 0xE3
     m_calib.dig_H4 = int16_t((uint16_t(data[3])<<8)|uint16_t((data[4]&0xF)<<4))>>4; // 0xE4:E5[3:0]
@@ -267,6 +240,7 @@
 
 // ======================================== LOW LEVEL API ========================================
 bool BME280::reset(void) {
+    m_bOk = false;
     if (write8(REG_RESET,VAL_RESET)) {
         wait_ms(2);
         m_mode = MODE_SLEEP;
@@ -315,4 +289,24 @@
 
 const BME280::calib_t& BME280::calib(void) const {
     return m_calib;
+}
+
+bool BME280::burst_read(uint8_t* data, uint8_t nBytes, uint8_t reg) {
+    if (m_pI2C==NULL) return false;
+    if (nBytes==0) return false;
+    if (data==NULL) return false;
+    uint8_t ok = 0x00;
+    m_pI2C->start();
+        ok = (ok<<1)|m_pI2C->write(m_address);
+        ok = (ok<<1)|m_pI2C->write(reg);
+        m_pI2C->start();
+        ok = (ok<<1)|m_pI2C->write(m_address|1);
+        for (int i=0; i<nBytes-1; i++) data[i] = m_pI2C->read(1);
+        data[nBytes-1] = m_pI2C->read(0);
+    m_pI2C->stop();
+    if (ok!=0x7) {
+        memset(data,0,nBytes);
+        return false;
+    }
+    return true;
 }
\ No newline at end of file