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#include "i2c.h"
#include "stm32.h"
void I2C::enable() {
RCC.enable(RCC.I2C2);
asm volatile("nop");
I2C2.CR1 = 0x8000;
I2C2.CR1 = 0;
I2C2.CR2 = 36;
I2C2.TRISE = 37;
I2C2.CCR = 180;
I2C2.CR1 = 1;
}
void I2C::write_reg(uint8_t addr, uint8_t reg, uint8_t data) {
I2C2.CR1 |= 0x100;
while(!(I2C2.SR1 & 0x01));
I2C2.DR = (addr << 1) | 0;
while (!(I2C2.SR1 & 0x02));
I2C2.SR2;
I2C2.DR = reg;
while (!(I2C2.SR1 & 0x80));
I2C2.DR = data;
while (!(I2C2.SR1 & 0x04));
I2C2.CR1 |= 0x200;
}
void I2C::read_reg(uint8_t addr, uint8_t reg, uint8_t len, uint8_t* buf) {
I2C2.CR1 |= 0x100;
while(!(I2C2.SR1 & 0x01));
I2C2.DR = (addr << 1) | 0;
while (!(I2C2.SR1 & 0x02));
I2C2.SR2;
I2C2.DR = reg;
while (!(I2C2.SR1 & 0x80));
I2C2.CR1 |= 0x100;
while(!(I2C2.SR1 & 0x01));
I2C2.DR = (addr << 1) | 1;
while (!(I2C2.SR1 & 0x02));
I2C2.SR2;
I2C2.CR1 |= 0x400; // Set ACK.
while(len) {
if(len == 3) {
while (!(I2C2.SR1 & 0x04)); // Wait for BTF
I2C2.CR1 &= ~0x400; // Clear ACK.
*buf++ = I2C2.DR;
len--;
I2C2.CR1 |= 0x200; // Set STOP.
*buf++ = I2C2.DR;
len--;
} else {
while (!(I2C2.SR1 & 0x40)); // Wait for RXNE
*buf++ = I2C2.DR;
len--;
}
}
}
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