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PatTheTrickster
PatTheTrickster
Associate II
September 14, 2023
Question

Receiving more than one byte for HAL_UART_Receive

  • September 14, 2023
  • 2 replies
  • 2310 views

I'm a bit confused on how to receive data with multiple bytes and store it to some buffer on the stm32 microcontroller?

Currently I have a python script that will send the data over uart serial "serial.Serial.write(b'4215'))"

Then I have a UART interrupt in my main loop that will capture only the first number but I have not been able to see the 215 when in debugging mode.

Just going to write the relevant code below since everything seems to be working right it's just I can't get more than one byte.

Any feedback is much appreciated! Let me know if I need to provide more information!

 

uint8_t Rx_buffer[100];
uint8_t msg_r_data[7];
uint8_t rx_indx = 0;
uint8_t msg_r_buffer[100];

....

while (1)
{
HAL_UART_Receive_IT(&hlpuart1, Rx_buffer, 4);
...
...

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
if (huart -> Instance == LPUART1) {
 msg_r_data[rx_indx++] = Rx_buffer[0];
}

}

 

This topic has been closed for replies.

2 replies

Issamos
Issamos
Super User
September 14, 2023

Hello @PatTheTrickster .

To make your request clearer, I suggest you to add your MCU reference and your full code if it's possible.

Best regards.

II

Tesla DeLorean
Tesla DeLorean
Guru
September 14, 2023

You don't start the process in a loop, you initiate it, and then restart in the callback

uint8_t Rx_buffer[1]; // You can do more than 1, but you could be left hanging, and need to process all in the callback
volatile uint8_t msg_r_data[7];
volatile uint8_t rx_indx = 0;

....

HAL_UART_Receive_IT(&hlpuart1, Rx_buffer, 1); // Initiate

while (1)
{
...
...

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
if (huart -> Instance == LPUART1) {
 msg_r_data[rx_indx++] = Rx_buffer[0]; // watch the index stays in scope
 HAL_UART_Receive_IT(&hlpuart1, Rx_buffer, 1); // Arm again
}

}

 

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