STM32F030 UART problem

[Francisco SinapseEnergia]

Posted on September 28, 2017 at 17:58

Hi all,

I'm trying to send an HTTP message through Ethernet interface using a WIFI external device. For this, I use HAL_UART functions as shown:

HAL_UART_Transmit(huart, messageTX,lengthOfmessage, timeoutTX);

UART has the following configuration:

static void MX_USART1_UART_Init(void)

{

huart1.Instance = USART1;

huart1.Init.BaudRate = 115200;

huart1.Init.WordLength = UART_WORDLENGTH_8B;

huart1.Init.StopBits = UART_STOPBITS_1;

huart1.Init.Parity = UART_PARITY_NONE;

huart1.Init.Mode = UART_MODE_TX_RX;

huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;

huart1.Init.OverSampling = UART_OVERSAMPLING_16;

huart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;

huart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;

if (HAL_UART_Init(&huart1) != HAL_OK)

{

_Error_Handler(__FILE__, __LINE__);

}

}

My tests results was (monitoring with Wireshark software):

1) Set the parameters as follows:

- messageTX = 'GET /registro/index.php/?solicitud=Hello HTTP/1.1\ \r\n Host:192.168.1.116\r\n\r\n'

- lengthOfmessage = 75

- timeoutTX = 100

Results are OK, messageTX is successfully sent

2) Set the parameters as follows:

- messageTX = GET /registro/index.php/?solicitud=<horfeus><firma><IP>192.168.1.160</IP><TipoCliente>4</TipoCliente><tiempo>23/01/2017-04:57:04</tiempo><edificio>53</edificio><TipoAula>6</TipoAula><aula>MA21FPLA1</aula><serie>00352738</serie></firma></horfeus> <horfeus><firma><IP>192.168.1.160</IP><TipoCliente>4</TipoCliente><tiempo>23/01/2017-04:57:04</tiempo><edificio>53</edificio><TipoAula>6</TipoAula><aula>MA21FPLA1</aula><serie>00352738</serie></firma></horfeus> HTTP/1.1\ \r\n Host:192.168.1.116\r\n\r\n'

- lengthOfmessage = 275

- timeoutTX = 100

Here, results are NOK, messageTX is not successfully sent. In Wireshark SW I receive a message with size 19 bytes. I think this size 19 indicates the size that exceeds my messageTX, i.e.:

messageTX(275 bytes) - messageReceived(19 bytes) = 256 bytes

So, it's possible that STM32f030 UART interface limits my messageTX size in 256 bytes?

Please, help me.

Thanks in advance.

[Vangelis Fortounas · Accepted solution]

Posted on September 28, 2017 at 18:22

Hello!

through Ethernet interface using a WIFI external device.

UART is capable to send more than 256 Bytes by calling HAL_UART_Transmit(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size, uint32_t Timeout). (Also IT Versions)

Is WiFi external device capable to handle more than  256 Bytes?

Check also the definition of 'message_length' in your code if it has 8bit width.

Regards

vf

[Tesla DeLorean]

Posted on September 28, 2017 at 18:22

>>So, it's possible that STM32f030 UART interface limits my message TX size in 256 bytes?

It is improbable, the USART one has a single byte holding register. Transmission would be limited by the data you provide, and the realistic transmission time for that data vs timeout.

Does your device require flow control?

[Francisco SinapseEnergia]

Posted on October 02, 2017 at 19:16

Yes! Problem was in lengthOfmessage definition (uint8_t in my case).

Thanks for your suppor! =)