Diff: BMP280/BMP280.cpp

Revision:

0:c23b55e3ca7d

Child:

1:94d75a291f23

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/BMP280/BMP280.cpp	Mon Sep 06 09:15:22 2021 +0000
@@ -0,0 +1,160 @@
+// capteur pression
+
+#include "mbed.h"
+#include "BMP280.h"
+
+//Constructeur
+BMP280::BMP280(PinName sda, PinName scl, char slave_adr)
+    :
+    i2c_p(new I2C(sda, scl)),
+    i2c(*i2c_p),
+    address(slave_adr<<1),
+    t_fine(0)
+{
+    initialize();
+}
+
+//Constructeur
+BMP280::BMP280(I2C &i2c_obj, char slave_adr)
+    :
+    i2c_p(NULL),
+    i2c(i2c_obj),
+    address(slave_adr<<1),
+    t_fine(0)
+{
+    initialize();
+}
+                            
+// Destructeur
+BMP280::~BMP280()
+{
+    if (NULL != i2c_p)
+        delete  i2c_p;
+}
+
+void BMP280::initialize()
+{
+    char cmd[18];
+
+    //cmd[0] = 0xf2;                    // ctrl_hum
+    //cmd[1] = 0x01;                    // suréchantillonage humidité x1
+    //i2c.write(address, cmd, 2);
+
+    cmd[0] = 0xf4;                      // ctrl_meas
+    //cmd[1] = 0x27;                    // suréchantillonage température x1, suréchantillonage pression x1, Mode Normal
+    cmd[1] = 0b01010111;                // suréchantillonage température x2 010, suréchantillonage pression x16 101, Mode Normal 11
+    i2c.write(address, cmd, 2);
+
+    cmd[0] = 0xf5;                      // config
+    cmd[1] = 0b10111100;                // Période Standby 1000ms, Filtre x16
+    i2c.write(address, cmd, 2);
+
+    cmd[0] = 0x88;                      // read dig_T regs
+    i2c.write(address, cmd, 1);
+    i2c.read(address, cmd, 6);
+
+    dig_T1 = (cmd[1] << 8) | cmd[0];
+    dig_T2 = (cmd[3] << 8) | cmd[2];
+    dig_T3 = (cmd[5] << 8) | cmd[4];
+
+    DEBUG_PRINT("dig_T = 0x%x, 0x%x, 0x%x\n\r", dig_T1, dig_T2, dig_T3);
+    DEBUG_PRINT("dig_T = %d, %d, %d\n\r", dig_T1, dig_T2, dig_T3);
+
+    cmd[0] = 0x8E; // read dig_P regs
+    i2c.write(address, cmd, 1);
+    i2c.read(address, cmd, 18);
+
+    dig_P1 = (cmd[ 1] << 8) | cmd[ 0];
+    dig_P2 = (cmd[ 3] << 8) | cmd[ 2];
+    dig_P3 = (cmd[ 5] << 8) | cmd[ 4];
+    dig_P4 = (cmd[ 7] << 8) | cmd[ 6];
+    dig_P5 = (cmd[ 9] << 8) | cmd[ 8];
+    dig_P6 = (cmd[11] << 8) | cmd[10];
+    dig_P7 = (cmd[13] << 8) | cmd[12];
+    dig_P8 = (cmd[15] << 8) | cmd[14];
+    dig_P9 = (cmd[17] << 8) | cmd[16];
+
+    DEBUG_PRINT("dig_P = 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n", dig_P1, dig_P2, dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9);
+        //
+        cmd[0] = 0xA1; // read dig_H regs
+      i2c.write(address, cmd, 1);
+      i2c.read(address, cmd, 1);
+       cmd[1] = 0xE1; // read dig_H regs
+      i2c.write(address, &cmd[1], 1);
+      i2c.read(address, &cmd[1], 7);
+
+      dig_H1 = cmd[0];
+      dig_H2 = (cmd[2] << 8) | cmd[1];
+      dig_H3 = cmd[3];
+      dig_H4 = (cmd[4] << 4) | (cmd[5] & 0x0f);
+      dig_H5 = (cmd[6] << 4) | ((cmd[5]>>4) & 0x0f);
+      dig_H6 = cmd[7];
+
+      DEBUG_PRINT("dig_H = 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n", dig_H1, dig_H2, dig_H3, dig_H4, dig_H5, dig_H6);
+    //
+}
+
+float BMP280::getTemperature()
+{
+    int32_t temp_raw;
+    float tempf;
+    char cmd[4];
+
+    cmd[0] = 0xfa; // temp_msb
+    i2c.write(address, cmd, 1);
+    i2c.read(address, &cmd[1], 3);
+
+    temp_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
+    DEBUG_PRINT("\r\ntemp_raw:%d",temp_raw);
+
+    int32_t temp1, temp2,temp;
+
+    temp1 =((((temp_raw >> 3) - (dig_T1 << 1))) * dig_T2) >> 11;
+    temp2 =(((((temp_raw >> 4) - dig_T1) * ((temp_raw >> 4) - dig_T1)) >> 12) * dig_T3) >> 14;
+    DEBUG_PRINT("   temp1:%d   temp2:%d",temp1, temp2);
+    t_fine = temp1+temp2;
+    DEBUG_PRINT("   t_fine:%d",t_fine);
+    temp = (t_fine * 5 + 128) >> 8;
+    tempf = (float)temp;
+    DEBUG_PRINT("   tempf:%f",tempf);
+
+    return (tempf/100.0f);
+}
+
+float BMP280::getPressure()
+{
+    uint32_t press_raw;
+    float pressf;
+    char cmd[4];
+
+    cmd[0] = 0xf7; // press_msb
+    i2c.write(address, cmd, 1);
+    i2c.read(address, &cmd[1], 3);
+
+    press_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
+
+    int32_t var1, var2;
+    uint32_t press;
+
+    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);
+}
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