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Initialize using gravity vectors to exclude the influence of the orientation during initialization #79

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Initialize using gravity vectors to exclude the influence of the orientation during initialization #79

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33d27f4
The previous method of subtracting gravity when calibrating accelerom…
Zhaosn Jan 31, 2024
66c7b9d
Never forget the concept of vectors now, huh?
Zhaosn Jan 31, 2024
a19a401
It's worth to note that my tests show it's maybe better to keep the c…
Zhaosn Jan 31, 2024
fbb3de4
Update MPU6050.cpp
Zhaosn Feb 1, 2024
9352961
Update MPU6050.cpp
Zhaosn Feb 1, 2024
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38 changes: 28 additions & 10 deletions src/MPU6050.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3392,23 +3392,25 @@ void MPU6050_Base::PID(uint8_t ReadAddress, float kP,float kI, uint8_t Loops){
uint8_t SaveAddress = (ReadAddress == 0x3B)?((getDeviceID() < 0x38 )? 0x06:0x77):0x13;

int16_t Data;
float Reading;
float Reading[3];
int16_t BitZero[3];
uint8_t shift =(SaveAddress == 0x77)?3:2;
float Error, PTerm, ITerm[3];
float Error, PTerm, ITerm[3], rawG[3];
VectorFloat v_rawG, v_normG;
int16_t eSample;
uint32_t eSum;
uint16_t gravity = 8192; // prevent uninitialized compiler warning
if (ReadAddress == 0x3B) gravity = 16384 >> getFullScaleAccelRange();
uint16_t epsilon = gravity * 1.0E-96;
Serial.write('>');
for (int i = 0; i < 3; i++) {
I2Cdev::readWords(devAddr, SaveAddress + (i * shift), 1, (uint16_t *)&Data, I2Cdev::readTimeout, wireObj); // reads 1 or more 16 bit integers (Word)
Reading = Data;
Reading[i] = Data;
if(SaveAddress != 0x13){
BitZero[i] = Data & 1; // Capture Bit Zero to properly handle Accelerometer calibration
ITerm[i] = ((float)Reading) * 8;
ITerm[i] = ((float)Reading[i]) * 8;
} else {
ITerm[i] = Reading * 4;
ITerm[i] = Reading[i] * 4;
}
}
for (int L = 0; L < Loops; L++) {
Expand All @@ -3417,10 +3419,26 @@ void MPU6050_Base::PID(uint8_t ReadAddress, float kP,float kI, uint8_t Loops){
eSum = 0;
for (int i = 0; i < 3; i++) {
I2Cdev::readWords(devAddr, ReadAddress + (i * 2), 1, (uint16_t *)&Data, I2Cdev::readTimeout, wireObj); // reads 1 or more 16 bit integers (Word)
Reading = Data;
if ((ReadAddress == 0x3B)&&(i == 2)) Reading -= gravity; //remove Gravity
Error = -Reading;
eSum += abs(Reading);
Reading[i] = Data;
rawG[i] = Data;
if ((ReadAddress == 0x3B)&&(i == 2)) {
v_rawG.x = rawG[0];
v_rawG.y = rawG[1];
v_rawG.z = rawG[2];
if (v_rawG.getMagnitude() < gravity + epsilon && v_rawG.getMagnitude() > gravity - epsilon) {
// do nothing
}else {
v_normG = v_rawG.getNormalized();
}
Reading[0] -= gravity * v_normG.x; //remove Gravity
Reading[1] -= gravity * v_normG.y;
Reading[2] -= gravity * v_normG.z;
}
}
for (int i = 0; i < 3; i++) {
if (isnan(Reading[i])) {Reading[i] = 0;}
Error = -Reading[i];
eSum += abs(Reading[i]);
PTerm = kP * Error;
ITerm[i] += (Error * 0.001) * kI; // Integral term 1000 Calculations a second = 0.001
if(SaveAddress != 0x13){
Expand Down Expand Up @@ -3475,4 +3493,4 @@ void MPU6050_Base::PrintActiveOffsets() {
Serial.print((float)offsets[3], 5); Serial.print(",\t");
Serial.print((float)offsets[4], 5); Serial.print(",\t");
Serial.print((float)offsets[5], 5); Serial.print("\n\n");
}
}