Diff: BMX055.cpp

Revision:

29:cd963a6d31c5

Parent:

28:21dfb161c67c

Child:

30:9b0cd3caf0ec

diff -r 21dfb161c67c -r cd963a6d31c5 BMX055.cpp
--- a/BMX055.cpp	Mon Jan 20 12:41:13 2020 +0000
+++ b/BMX055.cpp	Mon Jan 27 09:23:58 2020 +0000
@@ -52,7 +52,7 @@
     dt[0] = 0x02;
     i2c.write(chip_addr, dt, 1, true);
     i2c.read(chip_addr, dt, 6, false);
-    x = dt[1] << 8 | (dt[0] & 0xf0);
+    x = dt[1] << 8 | (dt[0] & 0xf0); // values have to be divided by 16
     y = dt[3] << 8 | (dt[2] & 0xf0);
     z = dt[5] << 8 | (dt[4] & 0xf0);
     accX = (float)x * acc_factor;
@@ -79,20 +79,22 @@
  
 void BMX055::readMag(void)
 {
-    int16_t x,y,z,msb_data;
+    int16_t x,y,z;
+
     chip_addr = inf_addr.mag_addr;
     dt[0] = 0x42;
     i2c.write(chip_addr, dt, 1, true);
     i2c.read(chip_addr, dt, 6, false);
-    // folgende Implementierung ist im original verkehrt!!!, verwende von https://github.com/kriswiner/BMX-055/blob/master/BMX055_MS5637_BasicAHRS_t3.ino
-    // Zeile 797 (altb Dez 2019)
-    x = (int16_t) (((int16_t)dt[1] << 8) | dt[0]) >> 3;  // 13-bit signed integer for x-axis field
-    y = (int16_t) (((int16_t)dt[3] << 8) | dt[2]) >> 3;  // 13-bit signed integer for x-axis field
-    z = (int16_t) (((int16_t)dt[5] << 8) | dt[4]) >> 1;  // 13-bit signed integer for x-axis field
     
-    magX = (float)y * 0.01f;       // MAGNETOMETER x-y are switched, see BMX055 datasheet page 161
-    magY = (float)x * 0.01f;       // x-y is switched
-    magZ = (float)z * 0.01f;       // z is z
+    // corrected, pmic 21.01.2020
+    x = dt[1] << 8 | (dt[0] & 0xf8); // value has to be divided by 8
+    y = dt[3] << 8 | (dt[2] & 0xf8); // value has to be divided by 8
+    z = dt[5] << 8 | (dt[4] & 0xfe); // value has to be divided by 2
+    
+    // scaling factor 1/301.5815f if experimentally validated in comparision to pes board -> approx. same scaling of mag values, pmic 21.01.2020
+    magX = -(float)y / 8.0f / 301.5815f;       // MAGNETOMETER x-y are switched, see BMX055 datasheet page 161, also measurements show change in sign x!!!
+    magY = (float)x / 8.0f / 301.5815f;       // x-y is switched
+    magZ = -(float)z / 2.0f / 301.5815f;       // z is -z
 }
  
 float BMX055::get_chip_temperature()
@@ -188,15 +190,15 @@
     // MAG
     chip_addr = inf_addr.mag_addr;
     dt[0] = 0x4b;   // Select Mag register
-    dt[1] = 0x83;   // Soft reset
+    dt[1] = 0x83;   // Soft reset 10000011
     i2c.write(chip_addr, dt, 2, false);
     wait_ms(10);
     dt[0] = 0x4b;   // Select Mag register
-    dt[1] = 0x01;   // Soft reset
+    dt[1] = 0x01;   // Soft reset 00000001
     i2c.write(chip_addr, dt, 2, false);
     wait_ms(10);
     dt[0] = 0x4c;   // Select Mag register
-    dt[1] = bmx055_parameters.mag_odr;
+    dt[1] = bmx055_parameters.mag_odr << 3; // corrected, pmic 20.01.2020
     i2c.write(chip_addr, dt, 2, false);
     wait_ms(1);
     dt[0] = 0x4e;   // Select Mag register
@@ -204,11 +206,11 @@
     i2c.write(chip_addr, dt, 2, false);
     wait_ms(1);
     dt[0] = 0x51;   // Select Mag register
-    dt[1] = 0x04;   // No. of Repetitions for X-Y Axis = 9
+    dt[1] = 0x51;   // No. of Repetitions for X-Y Axis = 163, fmaxODR = 33.2060 Hz, pmic 21.01.2020
     i2c.write(chip_addr, dt, 2, false);
     wait_ms(1);
     dt[0] = 0x52;   // Select Mag register
-    dt[1] = 0x16;   // No. of Repetitions for Z-Axis = 15
+    dt[1] = 0x0a;   // No. of Repetitions for Z-Axis = 11, fmaxODR = 33.2060 Hz, pmic 21.01.2020
     i2c.write(chip_addr, dt, 2, false);
 #if 0
     // ACC