Raw Data Parsing in STM32Cube IDE

[uranyumx]

Hello,

I need to parse a raw data that I receive UART3 interface. Then, I will send to a PC to show results in serial monitor. Before implementing in the microcontroller, I tested my approach in a C compiler. A sample raw data in the buffer array and here is C code to do this job:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main() {
    char buffer[] = "e\nM0000\nPda7F85F3Fu;ba48D503Dp,10,288\nPda7F9234Bu;ba4E2C324p,10,288\nPda806EC24u;baAE16C6Dp,10,288\nPda807B031u;baB360495p,10,288\n*\n\n";
    char *token;
    token = strtok(buffer, "\n");
    int package_nr = 0;

    while (token != NULL) {
        if (strcmp(token, "e") == 0) {
            printf("Response begin\n");
        } else if (token[0] == 'M') {
            printf("Measuring...\n");
            package_nr = 0;
        } else if (token[0] == 'P') {
            if (package_nr++ == 0) {
                printf("Receiving measurement responses:");
            }
            printf("\n%d. ", package_nr);
            char *P = strchr(token, 'P');
            char *packageLine = P + 1;
            char *running = packageLine;
            char *param;
            while ((param = strtok_r(running, ";,", &running)) != NULL) {
                if (strlen(param) == 0) {
                    continue;
                }
                char paramIdentifier[3];
                char paramValue[10];
                strncpy(paramIdentifier, param, 2);
                paramIdentifier[2] = '\0';
                strncpy(paramValue, param + 2, 9);
                paramValue[9] = '\0';
                printf("%s%s ", paramIdentifier, paramValue);
            }
        } else if (strcmp(token, "*") == 0) {
            printf("\nMeasurement completed.\n");
            printf("%d data point(s) received.\n", package_nr);
        } else {
            printf("%s", token);
        }
        token = strtok(NULL, "\n");
    }

    return 0;
}

Then I got this result:

Response begin
Measuring...
Receiving measurement responses:
1. da7F85F3Fu ba48D503Dp 10 288
2. da7F9234Bu ba4E2C324p 10 288
3. da806EC24u baAE16C6Dp 10 288
4. da807B031u baB360495p 10 288
Measurement completed.
4 data point(s) received.

To implement this code in the microcontroller, I simply removed the buffer array and replace it with Rx_Buffer which collects all raw data with HAL_UART_RxCpltCallback function. Then, here is the modified code:

 while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
 
      char *token;
          char msg[100];
          token = strtok(RX_Buffer, "\n");

          while (token != NULL) {
              if (strcmp(token, "e") == 0) {
                  sprintf(msg, "Response begin\n");
                  HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), HAL_MAX_DELAY);
              } else if (token[0] == 'M') {
                  sprintf(msg, "Measuring...\n");
                  HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), HAL_MAX_DELAY);
                  package_nr = 0;
              } else if (token[0] == 'P') {
                  if (package_nr++ == 0) {
                      sprintf(msg, "Receiving measurement responses:");
                      HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), HAL_MAX_DELAY);
                  }
                  sprintf(msg, "\n%d. ", package_nr);
                  HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), HAL_MAX_DELAY);
                  char *P = strchr(token, 'P');
                  char *packageLine = P + 1;
                  char *running = packageLine;
                  char *param;
                  while ((param = strtok_r(running, ";,", &running)) != NULL) {
                      if (strlen(param) == 0) {
                          continue;
                      }
                      char paramIdentifier[3];
                      char paramValue[10];
                      strncpy(paramIdentifier, param, 2);
                      paramIdentifier[2] = '\0';
                      strncpy(paramValue, param + 2, 9);
                      paramValue[9] = '\0';
                      sprintf(msg, "%s%s ", paramIdentifier, paramValue);
                      HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), HAL_MAX_DELAY);
                  }
              } else if (strcmp(token, "*") == 0) {
                  sprintf(msg, "\nMeasurement completed.\n");
                  HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), HAL_MAX_DELAY);
                  sprintf(msg, "%d data point(s) received.\n", package_nr);
                  HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), HAL_MAX_DELAY);
              } else {
                  sprintf(msg, "%s", token);
                  HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), HAL_MAX_DELAY);
              }
              token = strtok(NULL, "\n");
          }
          return 0;


    }

Then I got this result in the serial monitor:

Response begin
              e!0006Receiving measurement responses:
                                                    1.

here is the callback function to accumulate the raw data:

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{

  if (huart->Instance == USART3)  // check if it's USART3 interrupt
  {
    RX_Buffer[RX_Counter++] = RX_Data[0];  // Store received data in buffer
    HAL_UART_Receive_IT(huart, RX_Data, 1); // Ready to receive next byte
  }

}

So what can be source of the problem to not get correctly set parsed data?

 

[doraemon]

Hello!

In the ST case, you are using buffers received by the microcontroller, and forwarded
to you at interrupt time.
How do you send the buffers to the microcontroller?
I mean, if you send like this from a command line:
e
M0000
Pda7F85F3Fu;ba48D503Dp,10,288
Pda7F9234Bu;ba4E2C324p,10,288
etc...

Then the microcontroller might process the first line ("e"), and you get
the response without the rest of the data, in this case no data at all.

The problem is not in the parser but in the receiving part. If you want to fix
this, then you have to accumulate data in a buffer until you have 2 consecutive
\n\n, and process the whole string.

So please first explain how you send the data to the microcontroller and we'll think
about it from there.

Dora.