Hello
I am beginner to MCU, I have set STM32F407 Discovery as a master on I2C communication with nucleo STM32F446RE as a slave. PC host connected to the STM32F407 via UART. The code for the master is
char RecBuff [20];
while (1)
{
HAL_UART_Receive(&huart2, command, 2, HAL_MAX_DELAY);
if(command[0] == 1)
{
HAL_UART_Receive(&huart2, (uint8_t*)RecBuff , command[1], HAL_MAX_DELAY);
}
uint8_t LL = strlen(RecBuff);
HAL_I2C_Master_Transmit(&hi2c3, Motor1,&LL, 1, HAL_MAX_DELAY);
HAL_I2C_Master_Transmit(&hi2c3, Motor1, (uint8_t*)RecBuff,LL, HAL_MAX_DELAY);
HAL_I2C_Master_Transmit(&hi2c3, Motor1, &d1, 1, HAL_MAX_DELAY);
}RecBuff holding a value of motor rotation comes from the host for example 5000. d1 is the direction
the code for the Nucleo is
char rotval_s[10];
uint32_t rotval_d;
while (1)
{
uint8_t MSG[50] = {'\0'};
HAL_I2C_Slave_Receive_IT(&hi2c3, &LL, 1);
HAL_I2C_Slave_Receive_IT(&hi2c3, (uint8_t*)rotval_s, LL);
HAL_I2C_Slave_Receive_IT(&hi2c3, &direction, 1);
rotval_d = atoi(rotval_s);
sprintf(MSG2, "%lu\n\r", echoval.motval);
if(direction == 0)
{
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_10, 1);
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_11, 0);
}
if(direction == 1)
{
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_10, 0);
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_11, 1);
}
if(direction == 2)
{
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_10, 0);
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_11, 0);
}
if(HAL_GPIO_ReadPin (GPIOA, GPIO_PIN_1))
{
val = ((TIM2->CNT)>>2);
if(val >= rotval_d)
{
direction = 2;
}
}else
{
val = ((TIM2->CNT)>>2);
if(val >= rotval_d)
{
direction = 2;
}
}
sprintf(MSG, "%lu\n\r", val);
HAL_UART_Transmit(&huart2, MSG, sizeof(MSG), HAL_MAX_DELAY);
}The non blocking code in Nucleo is used to enable MCU to send the current value of the motor encoder to COM port
the problem is when master send the first byte, which is the length of the next word, Nucleo acknowledge receive but then it does not acknowledge of the next coming byte as shown in Picture from logic analyzer
Hazim
