rewrite read 16bits

This commit is contained in:
2025-08-16 04:06:46 +08:00
parent 6cc7b2dae2
commit 77a6525168

318
Src/i2c.c
View File

@@ -156,7 +156,6 @@ i2c_result_t i2c_bus_reset(void) {
return I2C_RECOVERY_OK;
}
#ifdef DEBUG_VERBOSE
/**
* @brief 扫描I2C总线查找连接的设备
*
@@ -263,7 +262,6 @@ void i2c_scan(void) {
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TC) == RESET) {}
}
}
#endif
i2c_result_t i2c_write_16bits(uint8_t slave_addr, uint8_t reg_addr, uint8_t data[2]) {
uint8_t state = I2C_STATE_START;
@@ -429,198 +427,212 @@ i2c_result_t i2c_write_16bits(uint8_t slave_addr, uint8_t reg_addr, uint8_t data
}
i2c_result_t i2c_read_16bits(uint8_t slave_addr, uint8_t reg_addr, uint8_t *data) {
i2c_state_t state = I2C_STATE_START;
uint16_t timeout = 0;
uint8_t retry_count = 0;
bool write_phase = true;
uint8_t data_index = 0;
// 参数检查:防止空指针和非法地址
if (data == NULL || slave_addr > 0x7F) {
return I2C_RESULT_INVALID_PARAM;
}
i2c_state_t state = I2C_STATE_START;
bool read_cycle = false;
bool i2c_timeout_flag = false;
uint16_t timeout = 0;
uint8_t number_of_byte = 2;
/* enable acknowledge */
i2c_ack_config(I2C0, I2C_ACK_ENABLE);
while (!(i2c_timeout_flag)) {
while (retry_count < (uint8_t)I2C_MAX_RETRY) {
switch (state) {
case I2C_STATE_START:
if (RESET == read_cycle) {
/* i2c master sends start signal only when the bus is idle */
while (i2c_flag_get(I2C0, I2C_FLAG_I2CBSY) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout < I2C_TIME_OUT) {
/* whether to send ACK or not for the next byte */
i2c_ackpos_config(I2C0, I2C_ACKPOS_NEXT);
} else {
// i2c_bus_reset();
timeout = 0;
state = I2C_STATE_START;
#ifdef DEBUG_VERBOES
printf("i2c bus is busy in READ!\n");
#endif
}
}
/* send the start signal */
i2c_start_on_bus(I2C0);
timeout = 0;
// wait for bus to be idle
while (i2c_flag_get(I2C0, I2C_FLAG_I2CBSY) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
// send start condition
i2c_start_on_bus(I2C0);
state = I2C_STATE_SEND_ADDRESS;
timeout = 0;
break;
case I2C_STATE_SEND_ADDRESS:
/* i2c master sends START signal successfully */
/* wait for start condition to be sent */
while ((!i2c_flag_get(I2C0, I2C_FLAG_SBSEND)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout < I2C_TIME_OUT) {
if (RESET == read_cycle) {
i2c_master_addressing(I2C0, slave_addr << 1, I2C_TRANSMITTER);
state = I2C_STATE_CLEAR_ADDRESS;
} else {
i2c_master_addressing(I2C0, slave_addr << 1, I2C_RECEIVER);
i2c_ack_config(I2C0, I2C_ACK_DISABLE);
state = I2C_STATE_CLEAR_ADDRESS;
}
timeout = 0;
} else {
timeout = 0;
state = I2C_STATE_START;
read_cycle = RESET;
#ifdef DEBUG_VERBOES
printf("i2c master sends start signal timeout in READ!\n");
#endif
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
// send slave address
if (write_phase) {
/* write phase: send address with write bit */
i2c_master_addressing(I2C0, (slave_addr << 1), I2C_TRANSMITTER);
} else {
/* read phase: send address with read bit */
i2c_master_addressing(I2C0, (slave_addr << 1) | 0x01, I2C_RECEIVER);
}
state = I2C_STATE_CLEAR_ADDRESS;
timeout = 0;
break;
case I2C_STATE_CLEAR_ADDRESS:
/* address flag set means i2c slave sends ACK */
/* wait for address to be acknowledged */
while ((!i2c_flag_get(I2C0, I2C_FLAG_ADDSEND)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout < I2C_TIME_OUT) {
/* Check for NACK before clearing address flag */
if (i2c_flag_get(I2C0, I2C_FLAG_AERR)) {
/* NACK received - slave did not acknowledge address */
i2c_flag_clear(I2C0, I2C_FLAG_AERR);
i2c_stop_on_bus(I2C0);
#ifdef DEBUG_VERBOES
printf("i2c NACK received for address 0x%02X in read!\n", slave_addr);
#endif
return I2C_RESULT_NACK;
}
i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
if ((SET == read_cycle) && (1 == number_of_byte)) {
/* send a stop condition to I2C bus */
i2c_stop_on_bus(I2C0);
}
timeout = 0;
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* clear address flag, address flag set means i2c slave sends ACK */
i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
if (write_phase) {
state = I2C_STATE_TRANSMIT_DATA;
} else {
timeout = 0;
state = I2C_STATE_START;
read_cycle = RESET;
#ifdef DEBUG_VERBOES
printf("i2c master clears address flag timeout in READ!\n");
#endif
/* 读阶段配置ACK位置和禁用ACK针对2字节读取 */
i2c_ackpos_config(I2C0, I2C_ACKPOS_NEXT);
i2c_ack_config(I2C0, I2C_ACK_DISABLE);
state = I2C_STATE_RECEIVE_DATA;
data_index = 0;
}
timeout = 0;
break;
case I2C_STATE_TRANSMIT_DATA:
if (RESET == read_cycle) {
/* wait until the transmit data buffer is empty */
while ((!i2c_flag_get(I2C0, I2C_FLAG_TBE)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout < I2C_TIME_OUT) {
/* send the EEPROM's internal address to write to : only one byte address */
i2c_data_transmit(I2C0, reg_addr);
timeout = 0;
} else {
timeout = 0;
state = I2C_STATE_START;
read_cycle = RESET;
#ifdef DEBUG_VERBOES
printf("i2c master wait data buffer is empty timeout in READ!\n");
#endif
}
/* wait until BTC bit is set */
while ((!i2c_flag_get(I2C0, I2C_FLAG_BTC)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout < I2C_TIME_OUT) {
timeout = 0;
state = I2C_STATE_START;
read_cycle = SET;
} else {
timeout = 0;
state = I2C_STATE_START;
read_cycle = RESET;
#ifdef DEBUG_VERBOES
printf("i2c master sends register address timeout in READ!\n");
#endif
}
} else {
while (number_of_byte) {
timeout++;
if (2 == number_of_byte) {
/* wait until BTC bit is set */
while (!i2c_flag_get(I2C0, I2C_FLAG_BTC));
/* send a stop condition to I2C bus */
i2c_stop_on_bus(I2C0);
}
/* wait until RBNE bit is set */
if (i2c_flag_get(I2C0, I2C_FLAG_RBNE)) {
/* read a byte from the EEPROM */
*data = i2c_data_receive(I2C0);
/* point to the next location where the byte read will be saved */
data++;
/* decrement the read bytes counter */
number_of_byte--;
timeout = 0;
}
if (timeout > I2C_TIME_OUT) {
timeout = 0;
state = I2C_STATE_START;
read_cycle = 0;
#ifdef DEBUG_VERBOES
printf("i2c master sends data timeout in READ!\n");
#endif
}
}
timeout = 0;
state = I2C_STATE_STOP;
/* wait for transmit buffer to be empty */
while ((!i2c_flag_get(I2C0, I2C_FLAG_TBE)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send register address */
i2c_data_transmit(I2C0, reg_addr);
state = I2C_STATE_RESTART;
timeout = 0;
break;
case I2C_STATE_RESTART:
/* wait for byte transfer complete BTC: Bit Transfer Complete */
while ((!i2c_flag_get(I2C0, I2C_FLAG_BTC)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* generate repeated start condition */
i2c_start_on_bus(I2C0);
/* wait for repeated start condition to be sent */
timeout = 0;
while ((!i2c_flag_get(I2C0, I2C_FLAG_SBSEND)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send slave address with read bit */
i2c_master_addressing(I2C0, (slave_addr << 1) | 0x01, I2C_RECEIVER);
/* switch to read phase */
write_phase = false;
state = I2C_STATE_CLEAR_ADDRESS;
timeout = 0;
break;
case I2C_STATE_RECEIVE_DATA:
/* 等待BTC标志表示第一个字节接收完成 */
while ((!i2c_flag_get(I2C0, I2C_FLAG_BTC)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* 发送STOP条件 */
i2c_stop_on_bus(I2C0);
/* 读取第一个字节 */
data[0] = i2c_data_receive(I2C0);
/* 等待第二个字节接收完成 */
timeout = 0;
while ((!i2c_flag_get(I2C0, I2C_FLAG_RBNE)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* 读取第二个字节 */
data[1] = i2c_data_receive(I2C0);
state = I2C_STATE_STOP;
break;
case I2C_STATE_STOP:
/* i2c master sends STOP signal successfully */
/* wait for stop condition to complete */
while ((I2C_CTL0(I2C0) & I2C_CTL0_STOP) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout < I2C_TIME_OUT) {
timeout = 0;
state = I2C_STATE_END;
i2c_timeout_flag = I2C_OK;
} else {
timeout = 0;
state = I2C_STATE_START;
read_cycle = 0;
#ifdef DEBUG_VERBOES
printf("i2c master sends stop signal timeout in READ!\n");
#endif
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* i2c master sends STOP signal successfully */
/* success */
return I2C_RESULT_SUCCESS;
case I2C_STATE_ERROR:
/* send stop condition to release bus */
i2c_stop_on_bus(I2C0);
retry_count++;
if (retry_count >= I2C_MAX_RETRY) {
#ifdef DEBUG_VERBOES
printf("IIC read failed after %d retries\n", I2C_RETRY_MAX);
#endif
return I2C_RESULT_ERROR;
}
/* reset state machine for retry */
state = I2C_STATE_START;
write_phase = true;
data_index = 0;
timeout = 0;
/* small delay before retry */
delay_10us(10);
break;
default:
state = I2C_STATE_START;
read_cycle = 0;
i2c_timeout_flag = I2C_OK;
timeout = 0;
#ifdef DEBUG_VERBOES
printf("i2c master sends start signal in READ.\n");
#endif
break;
}
}
return I2C_RESULT_SUCCESS;
return I2C_RESULT_TIMEOUT;
}
#ifdef DEBUG_VERBOSE