Hello everyone,
I'm coming back to you regarding a synchronization problem between master and slave in I2C.
I'm making an I2C/UART debug interface, what I want to do is display a menu in a terminal-> When we receive an address from the master (sent in I2C) to the slave we authorize the user to enter his choice in the terminal-> after reading the choice we display it in the terminal and transmit it to the master (slave->master) -> then at the master level according to RxData = which normally should contain the choice sent by the slave except that this is not the case -> according to RxData if = 'b' lights green led, if = 'l' yellow led, else lights orange led.
To debug since it doesn't work as expected, when I receive all the address sent by the master, I send it to a process_data function and to force the issue, I send the 'b' character directly to the choice location, except that I receive nothing from the master and I get stuck in this loop:
while (__HAL_I2C_GET_FLAG(hi2c, I2C_FLAG_TXIS) == RESET)
{
/* Check if an error is detected */
if (I2C_IsErrorOccurred(hi2c, Timeout, Tickstart) != HAL_OK)
{
return HAL_ERROR;
}
/* Check for the Timeout */
if (Timeout != HAL_MAX_DELAY)
{
if (((HAL_GetTick() - Tickstart) > Timeout) || (Timeout == 0U))
{
if ((__HAL_I2C_GET_FLAG(hi2c, I2C_FLAG_TXIS) == RESET))
{
hi2c->ErrorCode |= HAL_I2C_ERROR_TIMEOUT;
hi2c->State = HAL_I2C_STATE_READY;
hi2c->Mode = HAL_I2C_MODE_NONE;
/* Process Unlocked */
__HAL_UNLOCK(hi2c);
return HAL_ERROR;
}
}
}
}
return HAL_OK;
}
except that by commenting on the two lines in process_data():
// HAL_I2C_DisableListen_IT(&hi2c1);
// __HAL_UART_CLEAR_OREFLAG(&hi2c1);
I manage to get out of the loop with a RxData = '\0'; and the orange led lights up despite the fact that I've transmitted the letter 'b' knowing that at slave level the return value of HAL_I2C_Slave_Transmit is HAL_BUSY
So I thought of setting breakpoints, and when I set them, I realized that the red LED was ON on the master, which corresponds to error_handler, which makes more sense because the return value of HAL_I2C_Slave_Transmit is HAL_BUSY.
I really need your help to move forward with my project.
PS: you'll find the code attached: i2c.c for the master and i2c_slave for the slave for me master it's an MCU: STM32L562VET6Q and for the slave it's a nucleo-L476RG board.
Thanks in advance for your answers.
Have a nice day!
