gy-521/src/gy521_driver/gy521_driver.c

160 lines
3.5 KiB
C

/*
* Author: Jake Goodwin
* Date: 2023
* Description:
*/
#include "gy521_driver.h"
#include <stdint.h>
/*Stuff for cmocka*/
#if UNIT_TESTING
extern void* _test_malloc(const size_t size, const char* file, const int line);
extern void* _test_calloc(const size_t number_of_elements, const size_t size,
const char* file, const int line);
extern void _test_free(void* const ptr, const char* file, const int line);
#define malloc(size) _test_malloc(size, __FILE__, __LINE__)
#define calloc(num, size) _test_calloc(num, size, __FILE__, __LINE__)
#define free(ptr) _test_free(ptr, __FILE__, __LINE__)
#endif // UNIT_TESTING
#define NUM_ACCEL_REGS 6
#define NUM_GYRO_REGS 6
/*
* ############################
* REGISTER MAP
* ############################
*/
enum gy521_map {
accel_xouth = 0x3B,
accel_xoutl,
accel_youth,
accel_youtl,
accel_zouth,
accel_zoutl,
temp_outh,
temp_outl,
gyro_xouth,
gyro_xoutl,
gyro_youth,
gyro_youtl,
gyro_zouth,
gyro_zoutl,
fifo_couth = 0x72,
fifo_contl,
fifo_r_w,
who_am_i,
};
/*
* ############################
* Structures
* ############################
*/
typedef struct{
uint16_t x;
uint16_t y;
uint16_t z;
}gyro_values_struct;
typedef struct{
uint16_t x;
uint16_t y;
uint16_t z;
}accel_values_struct;
struct gy521_module{
uint8_t slave_address;
gyro_values_struct gyro;
accel_values_struct accel;
};
/*
* ############################
* Helper/Private Functions
* ############################
*/
uint8_t read_register(gy521_module *m, enum gy521_map reg)
{
/*Load the data var with athe address of the register to read*/
uint8_t data = reg;
/*Indicate we want to read a value from the slave.*/
gy521_twi_rx(m->slave_address, &data, 1);
/*The value should now be in the data var*/
return data;
}
void write_register(gy521_module *m, enum gy521_map reg, uint8_t data)
{
gy521_twi_tx(m->slave_address, (uint8_t *) &reg, data);
}
/*
* ############################
* Function Definitions
* ############################
*/
gy521_module* gy521_new(void)
{
gy521_module *m = (gy521_module *)malloc(sizeof(gy521_module));
m->slave_address = 0x0;
return m;
}
void gy521_free(gy521_module *m)
{
free(m);
}
_Bool gy521_init(gy521_module *m, uint8_t slave_address) {
/*Check to make sure it's a valid address for this module*/
if((slave_address != TWI_GY521_ADDR1) && (slave_address != TWI_GY521_ADDR2)) {
m->slave_address = 0x0;
return 0;
}
/*Set the slave address of the module*/
m->slave_address = slave_address;
/*Make sure TWI is working and read the who_am_i register*/
uint8_t data = read_register(m, who_am_i);
if(data != m->slave_address) {
return 0;
}
return 1;
}
void gy521_update_accel(gy521_module *m)
{
m->accel.x = read_register(m, accel_xouth) <<8;
m->accel.x |= read_register(m, accel_xoutl);
m->accel.y = read_register(m, accel_youth) <<8;
m->accel.y |= read_register(m, accel_youtl);
m->accel.z = read_register(m, accel_zouth) <<8;
m->accel.z |= read_register(m, accel_zoutl);
}
void gy521_update_gyro(gy521_module *m)
{
m->gyro.x = read_register(m, gyro_xouth) <<8;
m->gyro.x |= read_register(m, gyro_xoutl);
m->gyro.y = read_register(m, gyro_youth) <<8;
m->gyro.y |= read_register(m, gyro_youtl);
m->gyro.z = read_register(m, gyro_zouth) <<8;
m->gyro.z |= read_register(m, gyro_zoutl);
}