good afternoon
I am trying to create an i2c bus that can get the gyro and accelerometer data that I intend to use to create my own spin on the balancing robot , the main objective of the build is not to build a robot but to lean about i2c, coding and the formulas and theory that make this project possible.
I have been scratching my head over this for about 2 weeks now with no luck at all.
have decided to brake the code up and then re read the registers after I have set them however i haven't even made it through the void set up.
when open the serial monitor and check the 3 registers that are printed I get values of 225 which in binary are 0b11111111 and i have set them to 0b00000000
also i have written all the code to read the gyro and I only receive 65535 which is 16 1s.
if anyone could shed a little light on this and explaine where i have gone wrong that would be great
Adam
Balanceing_robot.ino (1.76 KB)
Hi,
Welcome to the forum.
Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html
Do you mean MPU6050?
Did you google arduino MPU6050
There is a library to do the job you are trying to do.
https://playground.arduino.cc/Main/MPU-6050
Check that site out.
Tom.... 
Which Arduino do you use? The MPU works on 3.3V, so that you need an I2C level shifter when connecting to a 5V Arduino.
Hi,
OPs code
#include <Wire.h>
const int MPU = 0x68; // addresses for I2C devices
float GX, GY, GZ; // float values for Gyro
void setup() {
Wire.begin (); //Start I2C Communication
Serial.begin(9600); //Start Serial comunication
Wire.beginTransmission (MPU); // address MPU
Wire.write(0x6B); // address regiser 0x6b
Wire.write(0x00); // set all bits to 0
Wire.endTransmission(true);
Wire.beginTransmission(MPU); // address MPU
Wire.write(0x1b); //address register 0x1b
Wire.write(0x00); // set all bits to 0
Wire.endTransmission();
Wire.beginTransmission(MPU); // address MPU
Wire.write(0x1c); // address register 0x1c
Wire.write(0x00); // set all bits to 0
Wire.endTransmission();
Wire.beginTransmission(MPU); // check 8 bit values writen to the registers
Wire.requestFrom (0x6b,1);
uint8_t A = Wire.read();
Wire.endTransmission();
Wire.beginTransmission(MPU);
Wire.requestFrom (0x1B, 2);
uint8_t B = Wire.read();
uint8_t C = Wire.read();
Wire.endTransmission();
Serial.print("A ="); // print all 8 bit values to serial mounitor to be checked.
Serial.println(A);
Serial.print(" B =");
Serial.println(B);
Serial.print (" C =");
Serial.print(C);
}
void loop() {
// put your main code here, to run repeatedly:
Wire.beginTransmission(MPU);
Wire.write(0x3B);
Wire.endTransmission();
Wire.requestFrom(0x3B,2);
uint16_t D = Wire.read()<<8|Wire.read();
Serial.print (" D = ");
Serial.println(D);
}
I'm no expert on om Wire or I2C, but I think this line in void loop()
Wire.requestFrom(0x3B,2);
Should be;
Wire.requestFrom(MPU,2);
You are requesting data from the MPU address.
tronixstuff.com/2010/10/20/tutorial-arduino-and-the-i2c-bus/
It looks like a good tutorial
Tom..
Good morning all
thank you for the reply’s I will have a look at the tutorial tonight
I know there is a library for the MPU6050 however the whole aim of this exercise is to learn how to extract data from i2c devices and not just to use a reconstructed library this should enable me to only draw the data that I require for my project and keep the program size to a minimum.
The mpu6050 i am using is a generic one from the wounderfull eBay so I am not sold on it being perfect either I may order a new one from ardrifruit for peace of mind.
Also I was not aware that the device was 3.3v I have operated it at 5v so there is always a chance it is now damaged.
I will make some amendment and post the results once complet
Many thanks
Adam
Most boards include a 3.3V voltage regulator, so that feeding 5V at Vcc is okay. But the I2C signal levels may not be sufficient.