why when I run the GY521_pitch_roll_yaw example code, all the numbers slowly increase 0 -> 359 -> 0? #47
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I also tried another library, at lease the output numbers are stable, does not auto-incremental over time when the chip is not moving at all. But I have another data conversion issue: |
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@mw66 In the data you provided I see a repeating pattern that every 3 or 4 measurements the data changes a bit. You might try to switch of the throttling by setThrottle(false) and see if that improves your readings.
Your other issue, could it be that you need to calibrate ? line 200-210 |
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I got ~+/- 0.xx at zero degrees. |
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Can you run - GY521_test_1.ino for a few minutes? int ax = sensor.getAccelX();
int ay = sensor.getAccelY();
int az = sensor.getAccelZ();
int gx = sensor.getGyroX();
int gy = sensor.getGyroY();
int gz = sensor.getGyroZ();
int t = sensor.getTemperature(); |
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Capture another try, number going down this time: |
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looks like: fix the drifting problem, now the numbers are stable. |
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The raw measurements look indeed stable - maybe longer run needed to be sure.
It might be that the default throttle time is too large (10 milliseconds), need to investigate how it would affect the math. |
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Actually I concluded to quickly, it still drift slowly, but not as steady in one direction as not setting with PITCH 358.378 => 347.883 Is there any caching going on? why the math error accumulate? |
here is the output with floats: |
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Looks stable to me now, some random noise. |
PITCH 358.378 => 347.883 ~10 degree, still random noise? |
Sorry, my comment was on the Accelerometer gyroscope temperature data from the - GY521_test_1.ino. I need to investigate why the raw values are stable and the PITCH ROLL YAW are drifting. |
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Note: |
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Created a debug sketch that combines the raw accel + gyro + temp with the derived angle and pitch, roll yaw values. Can you generate e.g. 10-20 lines ? //
// FILE: GY521_test_debug.ino
// AUTHOR: Rob Tillaart
// PURPOSE: output raw and cooked data from sensor for analyzing.
// URL: https://github.com/RobTillaart/GY521
#include "GY521.h"
GY521 sensor(0x68);
uint32_t counter = 0;
void setup()
{
Serial.begin(115200);
Serial.println();
Serial.println(__FILE__);
Serial.print("GY521_LIB_VERSION: ");
Serial.println(GY521_LIB_VERSION);
Wire.begin();
delay(100);
while (sensor.wakeup() == false)
{
Serial.print(millis());
Serial.println("\tCould not connect to GY521: please check the GY521 address (0x68/0x69)");
delay(1000);
}
sensor.setAccelSensitivity(0); // 2g
sensor.setGyroSensitivity(0); // 250 degrees/s
sensor.setThrottle();
Serial.println("start...");
// set calibration values from calibration sketch.
sensor.axe = 0;
sensor.aye = 0;
sensor.aze = 0;
sensor.gxe = 0;
sensor.gye = 0;
sensor.gze = 0;
Serial.println("\n\tACCELEROMETER\t\tGYROSCOPE\t\tTEMP\tPRY\t\t\tANGLE");
Serial.println("\tax\tay\taz\tgx\tgy\tgz\tT\tPITCH\tROLL\tYAW\tX\tY\tZ");
}
void loop()
{
sensor.read();
float ax = sensor.getAccelX();
float ay = sensor.getAccelY();
float az = sensor.getAccelZ();
float gx = sensor.getGyroX();
float gy = sensor.getGyroY();
float gz = sensor.getGyroZ();
float t = sensor.getTemperature();
float pitch = sensor.getPitch();
float roll = sensor.getRoll();
float yaw = sensor.getYaw();
float x = sensor.getAngleX();
float y = sensor.getAngleY();
float z = sensor.getAngleZ();
Serial.print(counter);
Serial.print('\t');
Serial.print(ax, 3);
Serial.print('\t');
Serial.print(ay, 3);
Serial.print('\t');
Serial.print(az, 3);
Serial.print('\t');
Serial.print(gx, 3);
Serial.print('\t');
Serial.print(gy, 3);
Serial.print('\t');
Serial.print(gz, 3);
Serial.print('\t');
Serial.print(t, 3);
Serial.print('\t');
Serial.print(pitch, 3);
Serial.print('\t');
Serial.print(roll, 3);
Serial.print('\t');
Serial.print(yaw, 3);
Serial.print('\t');
Serial.print(x, 1);
Serial.print('\t');
Serial.print(y, 1);
Serial.print('\t');
Serial.print(z, 1);
Serial.println();
counter++;
// delay(1000);
}
// -- END OF FILE -- |
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Added the above sketch to the version 0.5.2 PR. |
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@mw66 Sorry for the inconvenience. |
Here you are: Thanks for looking into this issue. |
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@RobTillaart Just want to let you know, according to the discussion of the issue in other library, I may have a faulty chip, the data and conversation is here: |
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@mw66 For PRY I need more time to dive into the math, expect it will take a lot of time to understand. |
The words of jrowberg is about the math I need to dive into. To be continued |
You may also check this library: https://github.com/gabriel-milan/TinyMPU6050 where I can get stable ~80 degree reading for 90 degree chip position, so I think there maybe a bug in i2cdevlib (and mpu6050 since it uses the former). |
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Checking other peoples code is good to do after studying the math, just copying it without understanding is risky. |
I didn't move my chip, but:
it goes on and on.
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