Question
STM32F404VG USART 9 bit communication
I am working on a system where I send HEX commands through the USART3 of the STM32F407VG to the COM machine with its corresponding PC.
The particularity of this communication is that in each sending of frames, the first byte of the frame must be sent with the wake up bit activated. (9 bits - 9n1), the rest of the bytes must be sent with the wake up deactivated (8 bits - 8N1)
I have used this code in the CUBE ID but it doesn't work
void EnviarComando(uint8_t cmdEnTx[], int lenEnTx)
{
int InterByte = 5; // Tiempo Interbyte
int i = 1;
/*Envío del primer byte (address) en 9 bits */
huart3.Init.WordLength = UART_WORDLENGTH_9B;
HAL_UART_Transmit(&huart3, cmdEnTx, 1, InterByte);
/*Envío del resto de bytes en 8 bits */
huart3.Init.WordLength = UART_WORDLENGTH_8B;
while (i< lenEnTx)
{
HAL_UART_Transmit(&huart3, &cmdEnTx[i], 1, InterByte);
i++;
}
}The initial configuration of the USART 3 is this:
static void MX_USART3_UART_Init(void)
{
huart3.Instance = USART3;
huart3.Init.BaudRate = 19200;
huart3.Init.WordLength = UART_WORDLENGTH_8B;
huart3.Init.StopBits = UART_STOPBITS_1;
huart3.Init.Parity = UART_PARITY_NONE;
huart3.Init.Mode = UART_MODE_TX_RX;
huart3.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart3.Init.OverSampling = UART_OVERSAMPLING_16;
if (HAL_UART_Init(&huart3) != HAL_OK)
{
Error_Handler();
}
} The same I did with Arduino Mega and it works perfectly acting on the bits of the UART register.
This is the code I used for the Mega 2560
void sendCommand(byte temp[], int len) //Envío de trama a EGM
{
UCSR1B = 0b10011101; //9 bits on
serEgm.write(temp[0]); //envía primer byte( address máquina )
delay(5); //Default 1
UCSR1B = 0b10011100; //9 bits off
for (int i=1; i<len;i++)
{
serEgm.write(temp[i]); //envía el resto de bytes de la trama
delay(5);//Default 1
}
} I am blocked with this matter, so I appreciate in advance any ideas or contributions that allow me to solve this problem
Regards
