main.cpp

#include "mbed.h"
#include "SerialRPCInterface.h"
#include "MPU6050.h"
#include "QEI.h"
 
SerialRPCInterface SerialRPC(USBTX, USBRX, 115200);
 
float accel_x, accel_y, accel_z, gyro_x, gyro_y, gyro_z;
int r_enc, l_enc;
 
RPCVariable<float> rpc_accel_x(&accel_x, "accel_x");
RPCVariable<float> rpc_accel_y(&accel_y, "accel_y");
RPCVariable<float> rpc_accel_z(&accel_z, "accel_z");
RPCVariable<float> rpc_gryo_x(&gyro_x, "gyro_x");
RPCVariable<float> rpc_gryo_y(&gyro_y, "gyro_y");
RPCVariable<float> rpc_gryo_z(&gyro_z, "gyro_z");
RPCVariable<int>   rpc_r_enc(&r_enc, "r_enc");
RPCVariable<int>   rpc_l_enc(&l_enc, "l_enc");
QEI l_wheel (p29, p30, NC, 624);
QEI r_wheel (p11, p12, NC, 624);
 
MPU6050 mpu6050;
 
DigitalOut init_done(LED1);
DigitalOut imu_good(LED2);
DigitalOut main_loop(LED3);
 
int main() {
    init_done = 0;
    imu_good = 0;
    main_loop = 0;
    
    //Set up I2C
    i2c.frequency(400000);  // use fast (400 kHz) I2C
    
    volatile bool imu_ready = false;
    
    wait_ms(100);
    
    uint8_t whoami = mpu6050.readByte(MPU6050_ADDRESS, WHO_AM_I_MPU6050);
    
    if (whoami == 0x68) // WHO_AM_I should always be 0x68
    {
        mpu6050.MPU6050SelfTest(SelfTest);
        if(SelfTest[0] < 1.0f && SelfTest[1] < 1.0f && SelfTest[2] < 1.0f && SelfTest[3] < 1.0f && SelfTest[4] < 1.0f && SelfTest[5] < 1.0f) {
            mpu6050.resetMPU6050(); // Reset registers to default in preparation for device calibration
            mpu6050.calibrateMPU6050(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers  
            mpu6050.initMPU6050();
            mpu6050.getAres();
            mpu6050.getGres();
            imu_ready = true;
            imu_good = 1;
        }
    }
    
    init_done = 1;
    uint8_t loop_count = 10;
    while(1) {
        wait_ms(10);
        
        // Handle the encoders
        r_enc=r_wheel.getPulses();
        l_enc=l_wheel.getPulses();
        //pc.printf("Pulses are: %i, %i\r\n", l_enc,r_enc);
        
        if (!(--loop_count)) {
            loop_count = 10;
            main_loop = !main_loop;
        }
        
        if (imu_ready) {
            
            if(mpu6050.readByte(MPU6050_ADDRESS, INT_STATUS) & 0x01) {  // check if data ready interrupt
                mpu6050.readAccelData(accelCount);  // Read the x/y/z adc values
                mpu6050.readGyroData(gyroCount);  // Read the x/y/z adc values
 
                // Now we'll calculate the accleration value into actual g's
                accel_x = (float)accelCount[0]*aRes - accelBias[0];  // get actual g value, this depends on scale being set
                accel_y = (float)accelCount[1]*aRes - accelBias[1];   
                accel_z = (float)accelCount[2]*aRes - accelBias[2];  
               
                // Calculate the gyro value into actual degrees per second
                gyro_x = (float)gyroCount[0]*gRes - gyroBias[0];  // get actual gyro value, this depends on scale being set
                gyro_y = (float)gyroCount[1]*gRes - gyroBias[1];  
                gyro_z = (float)gyroCount[2]*gRes - gyroBias[2];
            }
        }
    }
}