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#include <stdio.h>
#include <stdlib.h>
#include "platform.h"
#include <string.h>
#include <unistd.h>
#include <math.h>
#include "stdatomic.h"
#define MPU6050_ADDR 0x68
#define MPU6050_RA_ACCEL_XOUT_H 0x3B
#define MPU6050_RA_ACCEL_XOUT_L 0x3C
#define MPU6050_RA_ACCEL_YOUT_H 0x3D
#define MPU6050_RA_ACCEL_YOUT_L 0x3E
#define MPU6050_RA_ACCEL_ZOUT_H 0x3F
#define MPU6050_RA_ACCEL_ZOUT_L 0x40
#define MPU6050_RA_TEMP_OUT_H 0x41
#define MPU6050_RA_TEMP_OUT_L 0x42
#define MPU6050_RA_GYRO_XOUT_H 0x43
#define MPU6050_RA_GYRO_XOUT_L 0x44
#define MPU6050_RA_GYRO_YOUT_H 0x45
#define MPU6050_RA_GYRO_YOUT_L 0x46
#define MPU6050_RA_GYRO_ZOUT_H 0x47
#define MPU6050_RA_GYRO_ZOUT_L 0x48
#define MPU6050_RA_PWR_MGMT_1 0x6B
#define MPU6050_RA_WHO_AM_I 0x75
#define SDA PIN_8_OFFSET
#define SCL PIN_9_OFFSET
#define LONG 25 // Equals ~400KHz
#define SHORT 5
//busy wait for the specified time
void wait_ms(uint64_t ms) {
static const uint64_t ms_tick = RTC_FREQ/1000;
volatile uint64_t * mtime = (uint64_t*) (CLINT_CTRL_ADDR + CLINT_MTIME);
uint64_t then = (ms_tick * ms) + *mtime;
while(*mtime<then);
}
inline void delay_number_of_nop(uint32_t count)
{
for(volatile uint32_t j = 0; j < count; j++)
{
asm("nop");
}
}
_Bool i2c_busy(void)
{
GPIO_REG(GPIO_INPUT_EN) |= ((0x1 << SCL) | (0x1 << SDA));
GPIO_REG(GPIO_OUTPUT_EN) &= ~((0x1 << SCL) | (0x1 << SDA));
return (GPIO_REG(GPIO_INPUT_VAL) & ((0x1 << SCL) | (0x1 << SDA))) != ((0x1 << SCL) | (0x1 << SDA));
}
void i2c_start(void)
{
GPIO_REG(GPIO_INPUT_EN) &= ~((0x1 << SDA) | (0x1 << SCL));
GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << SDA);
GPIO_REG(GPIO_OUTPUT_EN) |= (0x1 << SDA);
delay_number_of_nop(SHORT);
GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << SCL);
GPIO_REG(GPIO_OUTPUT_EN) |= (0x1 << SCL);
}
void i2c_repeated_start(void)
{
delay_number_of_nop(SHORT);
GPIO_REG(GPIO_OUTPUT_VAL) |= (0x1 << SCL);
GPIO_REG(GPIO_OUTPUT_EN) |= (0x1 << SCL);
delay_number_of_nop(SHORT);
i2c_start();
}
void i2c_stop(void)
{
GPIO_REG(GPIO_INPUT_EN) |= (0x1 << SCL);
GPIO_REG(GPIO_OUTPUT_EN) &= ~(0x1 << SCL);
delay_number_of_nop(SHORT);
GPIO_REG(GPIO_INPUT_EN) |= (0x1 << SDA);
GPIO_REG(GPIO_OUTPUT_EN) &= ~(0x1 << SDA);
}
void i2c_init(void)
{
//GPIO_REG(GPIO_IOF_EN) &= ((0x1 << SCL) | (0x1 << SDA));
GPIO_REG(GPIO_OUTPUT_EN) &= ~((0x1 << SCL) | (0x1 << SDA));
GPIO_REG(GPIO_PULLUP_EN) |= ((0x1 << SDA) | (0x1 << SCL));
GPIO_REG(GPIO_INPUT_EN) |= (0x1 << SDA) | (0x1 << SCL);
}
void i2c_send_bytes_rs(uint8_t* data, uint8_t size, _Bool rs, uint8_t* data_r, uint8_t size_r)
{
uint8_t address_r = data[0] | 0x01;
for(uint8_t ii=0; ii<size; ii++)
{
GPIO_REG(GPIO_INPUT_EN) &= ~(0x1 << SDA);
GPIO_REG(GPIO_OUTPUT_EN) |= (0x1 << SDA);
for(uint8_t i=0; i<9; i++)
{
delay_number_of_nop(SHORT);
if(i != 8)
{
if(data[ii] & 0x80)
GPIO_REG(GPIO_OUTPUT_VAL) |= (0x1 << SDA);
else
GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << SDA);
}
else
{
GPIO_REG(GPIO_INPUT_EN) |= (0x1 << SDA);
GPIO_REG(GPIO_OUTPUT_EN) &= ~(0x1 << SDA);
if((GPIO_REG(GPIO_INPUT_VAL) & (0x1 << SDA)) != 0x0)
{
printf("NO ACK\n");
}
GPIO_REG(GPIO_INPUT_EN) &= ~(0x1 << SDA);
GPIO_REG(GPIO_OUTPUT_EN) |= (0x1 << SDA);
if(rs == 0)
{
GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << SDA);
}
else
{
GPIO_REG(GPIO_OUTPUT_VAL) |= (0x1 << SDA);
}
}
delay_number_of_nop(LONG-SHORT);
GPIO_REG(GPIO_OUTPUT_VAL) |= (0x1 << SCL);
delay_number_of_nop(LONG);
GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << SCL);
data[ii] <<= 1;
}
}
if(rs == 0)
return;
GPIO_REG(GPIO_OUTPUT_VAL) |= (0x1 << SCL);
delay_number_of_nop(SHORT);
GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << SDA);
delay_number_of_nop(SHORT);
GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << SCL);
for(uint8_t i=0; i<9; i++)
{
delay_number_of_nop(SHORT);
if(i != 8)
{
if(address_r & 0x80)
GPIO_REG(GPIO_OUTPUT_VAL) |= (0x1 << SDA);
else
GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << SDA);
}
else
{
GPIO_REG(GPIO_INPUT_EN) |= (0x1 << SDA);
GPIO_REG(GPIO_OUTPUT_EN) &= ~(0x1 << SDA);
if((GPIO_REG(GPIO_INPUT_VAL) & (0x1 << SDA)) != 0x0)
{
printf("NO ACK\n");
}
}
delay_number_of_nop(LONG-SHORT);
GPIO_REG(GPIO_OUTPUT_VAL) |= (0x1 << SCL);
delay_number_of_nop(LONG);
GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << SCL);
address_r <<= 1;
}
// Receive Data
for(uint8_t ii=0; ii<size_r; ii++)
{
for(uint8_t i=0; i<9; i++)
{
GPIO_REG(GPIO_OUTPUT_VAL) |= (0x1 << SCL);
if(i!=8)
data_r[ii] <<= 1;
delay_number_of_nop(SHORT);
if(i!=8)
{
if((GPIO_REG(GPIO_INPUT_VAL) & (0x1 << SDA)) != 0x0)
{
data_r[ii] |= 0x1;
}
}
else if(ii == (size_r-1))
{
GPIO_REG(GPIO_INPUT_EN) &= ~(0x1 << SDA);
GPIO_REG(GPIO_OUTPUT_EN) |= (0x1 << SDA);
GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << SDA);
} else {
}
delay_number_of_nop(LONG-SHORT);
GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << SCL);
if((i==7) && (ii != (size_r-1))){
GPIO_REG(GPIO_INPUT_EN) &= ~(0x1 << SDA);
GPIO_REG(GPIO_OUTPUT_EN) |= (0x1 << SDA);
GPIO_REG(GPIO_OUTPUT_VAL) &= ~(0x1 << SDA);
}
delay_number_of_nop(LONG);
}
if(ii != (size_r-1)){
GPIO_REG(GPIO_INPUT_EN) |= (0x1 << SDA);
GPIO_REG(GPIO_OUTPUT_EN) &= ~(0x1 << SDA);
delay_number_of_nop(SHORT);
}
}
}
void write_byte(uint8_t address, uint8_t reg_addr, uint8_t val)
{
uint8_t temp[3];
uint8_t data;
temp[0]=address<<1;
temp[1]=reg_addr;
temp[2]=val;
while(i2c_busy());
i2c_start();
i2c_send_bytes_rs(temp, sizeof(temp), 0, &data, 1);
i2c_stop();
}
uint8_t read_byte(uint8_t address, uint8_t reg_addr)
{
uint8_t temp[2];
uint8_t data;
temp[0]=address<<1;
temp[1]=reg_addr;
while(i2c_busy());
i2c_start();
i2c_send_bytes_rs(temp, sizeof(temp), 1, &data, 1);
i2c_stop();
return data;
}
void read_bytes(uint8_t address, uint8_t reg_addr, uint8_t* data, uint8_t size)
{
uint8_t temp[2];
temp[0]=address<<1;
temp[1]=reg_addr;
while(i2c_busy());
i2c_start();
i2c_send_bytes_rs(temp, sizeof(temp), 1, data, size);
i2c_stop();
}
int main(int argc, char **argv)
{
uint8_t data;
uint8_t accel[6];
printf("BIT-BANG I2C DEMO with MPU-6050 IMU\n");
i2c_init();
printf("Power Management 1: 0x%02X\n", read_byte(MPU6050_ADDR, MPU6050_RA_PWR_MGMT_1));
write_byte(MPU6050_ADDR, MPU6050_RA_PWR_MGMT_1, 0x80);
wait_ms(10);
printf("Power Management 1: 0x%02X\n", read_byte(MPU6050_ADDR, MPU6050_RA_PWR_MGMT_1));
write_byte(MPU6050_ADDR, MPU6050_RA_PWR_MGMT_1, 0x00);
printf("CHIP_ID: 0x%02X\n", read_byte(MPU6050_ADDR, MPU6050_RA_WHO_AM_I));
printf("DONE\n");
while(1)
{
//for(uint8_t i=0; i<6; i++){
// accel[i]=read_byte(MPU6050_ADDR, 0x3B+i);
//}
read_bytes(MPU6050_ADDR, 0x3B, accel, 6);
int16_t x_accel = (accel[0]<<8)+accel[1];
int16_t y_accel = (accel[2]<<8)+accel[3];
int16_t z_accel = (accel[4]<<8)+accel[5];
float z_g = z_accel;
z_g = z_g/16384.0;
int32_t z_g_int = z_g*100;
z_g_int = abs(z_g_int);
printf("Gravity in Z %d.%d\n", z_g_int/100, z_g_int%100);
//printf("X: %06d, Y: %06d, Z: %06d\n", x_accel, y_accel, z_accel);
wait_ms(100);
}
return 0;
}
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