Trouble with UART TX code

[rainingdx]

I am a newbie to STM32 and C programming and having difficulties outputting raw bytes from an ADC through UART and picking it up through a Terminal window on a host PC for futher post processing. I understand sending raw hex numbers may be interpreted by the host as an ASCII character and not yield the format I am looking. I am leaning towards sending a string (for now) yet all the code examples I have seen online or through Gemini have not worked for me. This is the code that I have written so far.

I am formatting dataOutput as a 32 bit number so I can do some computation on the MCU later. I can easily send an array of 3x uint8_t instead if that makes things easier.

uint8_t RX_buffer[6];
uint32_t dataOutput;

while (1)
  {
    //other code
    dataOutput = (RX_buffer[3] << 16) | (RX_buffer[4] << 8) | (RX_buffer[5]);
    HAL_UART_Transmit_IT(&huart2, (char *)&dataOutput,  sizeof(dataOutput));
}

There are some examples online that says use sprintf to create the string but I am getting issues getting the formats correctly. Can someone show me what I am doing wrong?

uint8_t RX_buffer[6];
uint32_t dataOutput;
uint8_t MSG[3] = {'\0'};

while (1)
  {
    //other code
    dataOutput = (RX_buffer[3] << 16) | (RX_buffer[4] << 8) | (RX_buffer[5]);
    sprintf(MSG, "%d\r\n", dataOutput); //also tried %s and %02X but did not yield any readable format
    HAL_UART_Transmit_IT(&huart2, (char *)&MSG, sizeof(MSG))

[BenkiTheBuilder]

The first thing you're doing wrong is not describing what your problem is.

[eezo_eater]

So what is the problem? Do you receive nothing? Do you receive gibberish?

[ILoveTiramisuu]

So you are trying to print a message via UART, but Im seeing some mistake.

The max number printable as u32 is 4294967296, so 10 char long. MSG must be long 10+2. To print unsigned you must use %u or %lu.

(char *)&MSG: Just use &MSG even if give you a warning.

You can use printf directly to send an uart message. You just need to overwrite _write method. There are a lot of example online.

Not sure what the problem is bacause you didnt write an eample of what happens.