Diff: BME280.cpp

Revision:

1:7b525853bad0

Parent:

0:5ace1cc7a9f2

Child:

2:ee200b715195

--- a/BME280.cpp	Tue May 09 06:32:36 2017 +0000
+++ b/BME280.cpp	Wed May 10 09:11:01 2017 +0000
@@ -54,7 +54,9 @@
 #define REG_H2_LSB 0xE1
 #define REG_H2_MSB 0xE2
 #define REG_H3     0xE3
-
+#define REG_H4     0xE4
+#define REG_H5     0xE5
+#define REG_H6     0xE7
 
 /*
  * Register description
@@ -129,6 +131,28 @@
  * 0xFD bit[7:0] hum_msb[7:0]    MSB part uh[15:8]
  * 0xFE bit[7:0] hum_lsb[7:0]    LSB part  uh[7:0]
  */
+ /*
+  * Compensation parameter storage, naming and data type
+  * Register addr,  Register content,    Data type
+  * 0x88/0x89,      dig_T1[7:0]/[15:8],  unsigned short
+  * 0x8A/0x8B,      dig_T2[7:0]/[15:8],    signed short
+  * 0x8C/0x8D,      dig_T3[7:0]/[15:8],    signed short
+  * 0x8E/0x8F,      dig_P1[7:0]/[15:8],  unsigned short
+  * 0x90/0x91,      dig_P2[7:0]/[15:8],    signed short
+  * 0x92/0x93,      dig_P3[7:0]/[15:8],    signed short
+  * 0x94/0x95,      dig_P4[7:0]/[15:8],    signed short
+  * 0x96/0x97,      dig_P5[7:0]/[15:8],    signed short
+  * 0x98/0x99,      dig_P6[7:0]/[15:8],    signed short
+  * 0x9A/0x9B,      dig_P7[7:0]/[15:8],    signed short
+  * 0x9C/0x9D,      dig_P8[7:0]/[15:8],    signed short
+  * 0x9E/0x9F,      dig_P9[7:0]/[15:8],    signed short
+  * 0xA1,           dig_H1[7:0],         unsigned char
+  * 0xE1/0xE2,      dig_H2[7:0]/[15:8],    signed short
+  * 0xE3,           dig_H3[7:0],         unsigned char
+  * 0xE4/0xE5[3:0], dig_H4[11:4]/[3:0]  signed short
+  * 0xE5[7:4]/0xE6, dig_H5[3:0]/[11:4]  signed short
+  * 0xE7,           dig_H6[7:0],        signed char
+  */
 
 void BME280::init(void)
 {
@@ -140,12 +164,10 @@
     
     data[0] = REG_CTRL_MEAS ;
     data[1] = (0x3 << 5) /* temp oversample x4 */
-            | (0x3 << 3) /* pres oversample x4 */
+            | (0x3 << 2) /* pres oversample x4 */
             | (0x00)      /* Sleep Mode */
             ;
     writeRegs(data, 2) ;
-readRegs(REG_CTRL_MEAS, data, 1) ;
-printf("ctrl_meas: 0x%02X\n", data[0]) ;
     
     data[0] = REG_CONFIG ;
     data[1] = (0x4 << 5) /* standby 500ms */
@@ -179,10 +201,19 @@
     /* read dig_H regs */
     readRegs(REG_H1, data, 1) ;
     dig_H1 = data[0] ;
-    readRegs(REG_H2_LSB, data, 3) ;
+    readRegs(REG_H2_LSB, data, 2) ;
     dig_H2 = (data[1] << 8) | data[0] ;
-    dig_H3 = data[2] ;
+    readRegs(REG_H3, data, 1) ;
+    dig_H3 = data[0] ;
+    readRegs(REG_H4, data, 3) ; 
+    dig_H4 = (data[0] << 4) | (data[1] & 0x0F) ;
+    dig_H5 = (data[2] << 4) | (data[1] >> 4) ;  
+    readRegs(REG_H6, data, 1) ;
+    dig_H6 = data[0] ;
 // printf("dig_H1:0x%04X, dig_H2:0x%04X, dig_H3:0x%04X\n",dig_H1, dig_H2, dig_H3) ;    
+// printf("dig_H4:0x%04X, dig_H5:0x%04X, dig_H6:0x%04X\n",dig_H4, dig_H5, dig_H6) ;   
+ 
+    trigger() ; /* dummy measure */
 }
 
 BME280::BME280(PinName sda, PinName scl, int addr) 
@@ -199,11 +230,6 @@
     m_cs = new DigitalOut(cs, 1) ;
     m_spi = new SPI(mosi, miso, sck) ;
     m_spi->format(8, 3) ;
-#if 0
-#if defined (TARGET_KL25Z)
-    *((uint8_t *)0x40076000) |= 0x01 ; /* lsb first  */
-#endif
-#endif
     m_i2c = 0 ;
     m_addr = 0 ;
     init() ;
@@ -235,7 +261,6 @@
     *m_cs = 0 ;
     m_spi->write(addr | 0x80) ;
     for (int i = 0 ; i < len ; i++ ) {    
- //     m_spi->write((addr+i)|0x80) ;  // spacify address to read
       data[i] = m_spi->write((addr+i)|0x80) ; 
     } 
     m_spi->write(0x00) ; // to terminate read mode
@@ -245,7 +270,6 @@
 void BME280::spi_writeRegs(uint8_t * data, int len) {
    *m_cs = 0 ;
    for (int i = 0 ; i < len-1 ; i++ ) {
-// printf("writing 0x%02X := 0x%02X\n", (data[0]+i)^0x80, data[i+1]) ;
       m_spi->write((data[0]+i)^0x80) ; /* register address */
       m_spi->write(data[i+1]) ; /* data to write */
 
@@ -288,7 +312,6 @@
     data[1] = (data[1] & 0xFC) /* keep oversampling */
             | (0x2)      /* Forced Mode */
             ;
-//    data[1] = 0x38 | 0x02 ;
     writeRegs(data, 2) ;
 }
 
@@ -306,98 +329,74 @@
     return(data[0]) ;
 }
 
-void BME280::readData(uint8_t data[]) 
-{
-    readRegs(REG_PRESS_MSB, data, 8) ;
-printf("Data Read: ") ;    
-for(int i = 0 ; i < 8 ; i++ ) {
-    printf("%02X ", data[i]) ;
-}
-printf("\n") ;
-}
-
-float BME280::getTemperature(uint8_t data[]) 
+float BME280::getTemperature(void) 
 {
-    uint32_t temp_raw;
-    float tempf;
-//    uint8_t data[3];
- 
-//    readRegs(REG_TEMP_MSB, data, 3) ;
- 
-    temp_raw = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4);
- 
-    int32_t temp;
- 
-    temp =
-        (((((temp_raw >> 3) - (dig_T1 << 1))) * dig_T2) >> 11) +
-        ((((((temp_raw >> 4) - dig_T1) * ((temp_raw >> 4) - dig_T1)) >> 12) * dig_T3) >> 14);
- 
-    t_fine = temp;
-    temp = (temp * 5 + 128) >> 8;
-    tempf = (float)temp;
- 
+    float tempf ;
+    uint8_t data[3] ;
+    BME280_S32_t var1, var2, T ;
+    BME280_S32_t adc_T ;
+    
+    readRegs(REG_TEMP_MSB, data, 3) ;
+    adc_T = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4);
+    
+    var1 = ((((adc_T>>3) - ((BME280_S32_t)dig_T1<<1))) * ((BME280_S32_t)dig_T2)) >> 11;
+    var2 = (((((adc_T>>4) - ((BME280_S32_t)dig_T1)) * ((adc_T>>4) - ((BME280_S32_t)dig_T1))) >> 12) *
+        ((BME280_S32_t)dig_T3)) >> 14;
+    t_fine = var1 + var2;
+    T = (t_fine * 5 + 128) >> 8;
+    
+    tempf = (float)T;
     return (tempf/100.0f);
-    
 }
 
-float BME280::getHumidity(uint8_t data[]) 
+float BME280::getPressure(void) 
 {
-    uint32_t hum_raw;
-    float humf;
-//    uint8_t data[2];
+    BME280_S32_t adc_P ;
+    BME280_S64_t var1, var2, p ;
+    float pressf;
+    uint8_t data[3];
  
-//    readRegs(REG_HUM_MSB, data, 2) ;
- 
-    hum_raw = (data[0] << 8) | data[1];
- 
-    int32_t v_x1;
+    readRegs(REG_PRESS_MSB, data, 3) ;
+    adc_P = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4);
  
-    v_x1 = t_fine - 76800;
-    v_x1 =  (((((hum_raw << 14) -(((int32_t)dig_H4) << 20) - (((int32_t)dig_H5) * v_x1)) +
-               ((int32_t)16384)) >> 15) * (((((((v_x1 * (int32_t)dig_H6) >> 10) *
-                                            (((v_x1 * ((int32_t)dig_H3)) >> 11) + 32768)) >> 10) + 2097152) *
-                                            (int32_t)dig_H2 + 8192) >> 14));
-    v_x1 = (v_x1 - (((((v_x1 >> 15) * (v_x1 >> 15)) >> 7) * (int32_t)dig_H1) >> 4));
-    v_x1 = (v_x1 < 0 ? 0 : v_x1);
-    v_x1 = (v_x1 > 419430400 ? 419430400 : v_x1);
+    var1 = ((BME280_S64_t)t_fine) - 128000;
+    var2 = var1 * var1 * (BME280_S64_t)dig_P6;
+    var2 = var2 + ((var1*(BME280_S64_t)dig_P5)<<17);
+    var2 = var2 + (((BME280_S64_t)dig_P4)<<35);
+    var1 = ((var1 * var1 * (BME280_S64_t)dig_P3)>>8) + ((var1 * (BME280_S64_t)dig_P2)<<12);
+    var1 = (((((BME280_S64_t)1)<<47)+var1))*((BME280_S64_t)dig_P1)>>33;
+    if (var1 == 0) {
+        return 0; // avoid exception caused by division by zero
+    }
+    p = 1048576-adc_P;
+    p = (((p<<31)-var2)*3125)/var1;
+    var1 = (((BME280_S64_t)dig_P9) * (p>>13) * (p>>13)) >> 25;
+    var2 = (((BME280_S64_t)dig_P8) * p) >> 19;
+    p = ((p + var1 + var2) >> 8) + (((BME280_S64_t)dig_P7)<<4);
  
-    humf = (float)(v_x1 >> 12);
- 
-    return (humf/1024.0f);
+    pressf = (float)(p >> 8) ;
+    return (pressf/100.0f);
 }
 
-float BME280::getPressure(uint8_t data[]) 
+float BME280::getHumidity(void) 
 {
-    uint32_t press_raw;
-    float pressf;
-//    uint8_t data[3];
+    BME280_S32_t adc_H;
+    BME280_S32_t v_x1_u32r ;
+    float humf;
+    uint8_t data[2];
  
-//    readRegs(REG_PRESS_MSB, data, 3) ;
- 
-    press_raw = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4);
- 
-    int32_t var1, var2;
-    uint32_t press;
+    readRegs(REG_HUM_MSB, data, 2) ;
+    adc_H = (data[0] << 8) | data[1];
  
-    var1 = (t_fine >> 1) - 64000;
-    var2 = (((var1 >> 2) * (var1 >> 2)) >> 11) * dig_P6;
-    var2 = var2 + ((var1 * dig_P5) << 1);
-    var2 = (var2 >> 2) + (dig_P4 << 16);
-    var1 = (((dig_P3 * (((var1 >> 2)*(var1 >> 2)) >> 13)) >> 3) + ((dig_P2 * var1) >> 1)) >> 18;
-    var1 = ((32768 + var1) * dig_P1) >> 15;
-    if (var1 == 0) {
-        return 0;
-    }
-    press = (((1048576 - press_raw) - (var2 >> 12))) * 3125;
-    if(press < 0x80000000) {
-        press = (press << 1) / var1;
-    } else {
-        press = (press / var1) * 2;
-    }
-    var1 = ((int32_t)dig_P9 * ((int32_t)(((press >> 3) * (press >> 3)) >> 13))) >> 12;
-    var2 = (((int32_t)(press >> 2)) * (int32_t)dig_P8) >> 13;
-    press = (press + ((var1 + var2 + dig_P7) >> 4));
- 
-    pressf = (float)press;
-    return (pressf/100.0f);
+    v_x1_u32r = (t_fine - ((BME280_S32_t)76800));
+    v_x1_u32r = (((((adc_H << 14) - (((BME280_S32_t)dig_H4) << 20) - (((BME280_S32_t)dig_H5) * v_x1_u32r)) +
+        ((BME280_S32_t)16384)) >> 15) * (((((((v_x1_u32r * ((BME280_S32_t)dig_H6)) >> 10) * (((v_x1_u32r *
+        ((BME280_S32_t)dig_H3)) >> 11) + ((BME280_S32_t)32768))) >> 10) + ((BME280_S32_t)2097152)) *
+        ((BME280_S32_t)dig_H2) + 8192) >> 14));
+    v_x1_u32r = (v_x1_u32r - (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7) * ((BME280_S32_t)dig_H1)) >> 4));
+    v_x1_u32r = (v_x1_u32r < 0 ? 0 : v_x1_u32r);
+    v_x1_u32r = (v_x1_u32r > 419430400 ? 419430400 : v_x1_u32r);
+    humf = (float)(v_x1_u32r >> 12) ;
+
+    return (humf/1024.0f);
 }
\ No newline at end of file