MPU-6050 & tiva C launch pad tm4c123

[mahmoudhamdy]

i tried to use the library on energia and everything worked fine but when i print the raw values they arenot stable at all it goes up and down strangely with no reason and with no movement however it works fine on arduino ! ..

anyone can help ?

[udawat]

Seems to be working with the latest Energia version (0101E0011). Can you try DMP code?

[mahmoudhamdy]

yea i have the last version .. first i tried the DMP code .. i get these errors from the example code MPU6050_DMP6.ino: In function 'void setup()': MPU6050_DMP6.ino:165:9: error: 'TWBR' was not declared in this scope MPU6050_DMP6.ino:174:13: error: no match for 'operator!' in '!Serial' MPU6050_DMP6.ino:174:13: note: candidate is: MPU6050_DMP6.ino:174:13: note: operator!(bool) MPU6050_DMP6.ino:174:13: note: no known conversion for argument 1 from 'HardwareSerial' to 'bool'

so i commented that lines and tried then it says

Initializing I2C devices... Testing device connections... MPU6050 connection successful

Send any character to begin DMP programming and demo: Initializing DMP... DMP Initialization failed (code 1)

however the raw values example works and print values but the unstable values

[mahmoudhamdy]

is it sthg with I2C clock ? as // TWBR = 24; // 400kHz I2C clock (200kHz if CPU is 8MHz)

elif I2CDEV_IMPLEMENTATION == I2CDEV_BUILTIN_FASTWIRE

    Fastwire::setup(400, true);
#endif

and tiva c is 80 MHZ

[udawat]

I can confirm that i am getting correct readings. Take a look at the snapshot attached. Code uses Pins 23 and 24 on Jumper J3 for SCL and SDA. Also, note that the baud rate must be 9600. This is a limit for the TM4C123G IC. Code is as follows:

void setup() {
    // join I2C bus (I2Cdev library doesn't do this automatically)
    Wire.begin(3);
    Wire.setModule(3);
    Wire.begin();
    // initialize serial communication
    // (38400 chosen because it works as well at 8MHz as it does at 16MHz, but
    // it's really up to you depending on your project)
    Serial.begin(9600);

    // initialize device
    Serial.println("Initializing I2C devices...");
    accelgyro.initialize();

[udawat]

Board used is a custom 9 Degrees of Freedom board. http://www.explorelabs.com/imu-9-dof-fusion-mpu6150-hmc5883l-i2c-auto-voltage-shift.html

[mahmoudhamdy]

this what i get when i use the same connection with MPU-6050

[mahmoudhamdy]

it is stable and readings arenot close

[udawat]

I believe you should not be getting a reading of more than 32768/2 for gyro. I am not sure. What hardware are you using? Also, what modifications have you done to the original MPU6050_RAW sketch?

[mahmoudhamdy]

tiva c launch pad tm4c123 .. MPU6050 invense board ... i connected the vcc to 3.3 and gnd to gnd .. SCL to PA6 and SDA to PA7 .. and here is my code

// I2C device class (I2Cdev) demonstration Arduino sketch for MPU6050 class // 10/7/2011 by Jeff Rowberg jeff@rowberg.net // Updates should (hopefully) always be available at https://github.com/jrowberg/i2cdevlib // // Changelog: // 2013-05-08 - added multiple output formats // - added seamless Fastwire support // 2011-10-07 - initial release

/* ============================================ I2Cdev device library code is placed under the MIT license Copyright (c) 2011 Jeff Rowberg

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

THE SOFTWARE.

*/

// I2Cdev and MPU6050 must be installed as libraries, or else the .cpp/.h files // for both classes must be in the include path of your project

include "I2Cdev.h"

include "MPU6050.h"

// Arduino Wire library is required if I2Cdev I2CDEV_ARDUINO_WIRE implementation // is used in I2Cdev.h

if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE

#include "Wire.h"

endif

// class default I2C address is 0x68 // specific I2C addresses may be passed as a parameter here // AD0 low = 0x68 (default for InvenSense evaluation board) // AD0 high = 0x69 MPU6050 accelgyro; //MPU6050 accelgyro(0x69); // <-- use for AD0 high

int16_t ax, ay, az; int16_t gx, gy, gz;

// uncomment "OUTPUT_READABLE_ACCELGYRO" if you want to see a tab-separated // list of the accel X/Y/Z and then gyro X/Y/Z values in decimal. Easy to read, // not so easy to parse, and slow(er) over UART.

define OUTPUT_READABLE_ACCELGYRO

// uncomment "OUTPUT_BINARY_ACCELGYRO" to send all 6 axes of data as 16-bit // binary, one right after the other. This is very fast (as fast as possible // without compression or data loss), and easy to parse, but impossible to read // for a human. //#define OUTPUT_BINARY_ACCELGYRO

define LED_PIN 13

bool blinkState = false;

void setup() { // join I2C bus (I2Cdev library doesn't do this automatically)

    Wire.begin();
    Wire.setModule(1);

// initialize serial communication
// (38400 chosen because it works as well at 8MHz as it does at 16MHz, but
// it's really up to you depending on your project)
Serial.begin(9600);

// initialize device
Serial.println("Initializing I2C devices...");
accelgyro.initialize();

// verify connection
Serial.println("Testing device connections...");
Serial.println(accelgyro.testConnection() ? "MPU6050 connection successful" : "MPU6050 connection failed");

// use the code below to change accel/gyro offset values
/*
Serial.println("Updating internal sensor offsets...");
// -76  -2359   1688    0   0   0
Serial.print(accelgyro.getXAccelOffset()); Serial.print("\t"); // -76
Serial.print(accelgyro.getYAccelOffset()); Serial.print("\t"); // -2359
Serial.print(accelgyro.getZAccelOffset()); Serial.print("\t"); // 1688
Serial.print(accelgyro.getXGyroOffset()); Serial.print("\t"); // 0
Serial.print(accelgyro.getYGyroOffset()); Serial.print("\t"); // 0
Serial.print(accelgyro.getZGyroOffset()); Serial.print("\t"); // 0
Serial.print("\n");
accelgyro.setXGyroOffset(220);
accelgyro.setYGyroOffset(76);
accelgyro.setZGyroOffset(-85);
Serial.print(accelgyro.getXAccelOffset()); Serial.print("\t"); // -76
Serial.print(accelgyro.getYAccelOffset()); Serial.print("\t"); // -2359
Serial.print(accelgyro.getZAccelOffset()); Serial.print("\t"); // 1688
Serial.print(accelgyro.getXGyroOffset()); Serial.print("\t"); // 0
Serial.print(accelgyro.getYGyroOffset()); Serial.print("\t"); // 0
Serial.print(accelgyro.getZGyroOffset()); Serial.print("\t"); // 0
Serial.print("\n");
*/

// configure Arduino LED for
pinMode(LED_PIN, OUTPUT);

}

void loop() { // read raw accel/gyro measurements from device accelgyro.getMotion6(&ax, &ay, &az, &gx, &gy, &gz);

// these methods (and a few others) are also available
//accelgyro.getAcceleration(&ax, &ay, &az);
//accelgyro.getRotation(&gx, &gy, &gz);

#ifdef OUTPUT_READABLE_ACCELGYRO
    // display tab-separated accel/gyro x/y/z values
    Serial.print("a/g:\t");
    Serial.print(ax); Serial.print("\t");
    Serial.print(ay); Serial.print("\t");
    Serial.print(az); Serial.print("\t");
    Serial.print(gx); Serial.print("\t");
    Serial.print(gy); Serial.print("\t");
    Serial.println(gz);
#endif

#ifdef OUTPUT_BINARY_ACCELGYRO
    Serial.write((uint8_t)(ax >> 8)); Serial.write((uint8_t)(ax & 0xFF));
    Serial.write((uint8_t)(ay >> 8)); Serial.write((uint8_t)(ay & 0xFF));
    Serial.write((uint8_t)(az >> 8)); Serial.write((uint8_t)(az & 0xFF));
    Serial.write((uint8_t)(gx >> 8)); Serial.write((uint8_t)(gx & 0xFF));
    Serial.write((uint8_t)(gy >> 8)); Serial.write((uint8_t)(gy & 0xFF));
    Serial.write((uint8_t)(gz >> 8)); Serial.write((uint8_t)(gz & 0xFF));
#endif

// blink LED to indicate activity
blinkState = !blinkState;
digitalWrite(LED_PIN, blinkState);

}

thank you for ur response !

[udawat]

I see that you are using offset values. Just for testing purpose, can you try the original code. Maybe, a glitch in setting the offset values.

[mahmoudhamdy]

no they are commented .. should i try pulling up SCL and SDA pins to 3.3 V ?

[udawat]

If you are using this board: https://www.sparkfun.com/products/11028 Then, it has pull ups on the board. They are enabled by default. I2C interface does not seem to be a problem. It should be related to Energia and Wire Library implementation in Energia.

[mahmoudhamdy]

yea that is the board i am using .. so i should check the wire library ?

[Hrishikeshkunchepu]

Hi, mahmoudhamdy, did you get the output correctly?

[jrowberg]

Closing ancient issue for cleanup.