Tengo el siguiente circuito que conecta dos stm32F4
a través del SN65HVDA195-Q1
LIN-transciever.
En la biblioteca UART stm32F4, encontré la siguiente implementación de LIN:
===============================================================================
LIN mode functions
===============================================================================
This subsection provides a set of functions allowing to manage the USART LIN
Mode communication.
In LIN mode, 8-bit data format with 1 stop bit is required in accordance with
the LIN standard.
Only this LIN Feature is supported by the USART IP:
- LIN Master Synchronous Break send capability and LIN slave break detection
capability : 13-bit break generation and 10/11 bit break detection
USART LIN Master transmitter communication is possible through the following procedure:
1. Program the Baud rate, Word length = 8bits, Stop bits = 1bit, Parity,
Mode transmitter or Mode receiver and hardware flow control values using
the USART_Init() function.
2. Enable the USART using the USART_Cmd() function.
3. Enable the LIN mode using the USART_LINCmd() function.
4. Send the break character using USART_SendBreak() function.
USART LIN Master receiver communication is possible through the following procedure:
1. Program the Baud rate, Word length = 8bits, Stop bits = 1bit, Parity,
Mode transmitter or Mode receiver and hardware flow control values using
the USART_Init() function.
2. Enable the USART using the USART_Cmd() function.
3. Configures the break detection length using the USART_LINBreakDetectLengthConfig()
function.
4. Enable the LIN mode using the USART_LINCmd() function.
@note In LIN mode, the following bits must be kept cleared:
- CLKEN in the USART_CR2 register,
- STOP[1:0], SCEN, HDSEL and IREN in the USART_CR3 register.
@endverbatim
* @{
*/
/**
* @brief Sets the USART LIN Break detection length.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param USART_LINBreakDetectLength: specifies the LIN break detection length.
* This parameter can be one of the following values:
* @arg USART_LINBreakDetectLength_10b: 10-bit break detection
* @arg USART_LINBreakDetectLength_11b: 11-bit break detection
* @retval None
*/
void USART_LINBreakDetectLengthConfig(USART_TypeDef* USARTx, uint16_t USART_LINBreakDetectLength)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_USART_LIN_BREAK_DETECT_LENGTH(USART_LINBreakDetectLength));
USARTx->CR2 &= (uint16_t)~((uint16_t)USART_CR2_LBDL);
USARTx->CR2 |= USART_LINBreakDetectLength;
}
/**
* @brief Enables or disables the USART's LIN mode.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @param NewState: new state of the USART LIN mode.
* This parameter can be: ENABLE or DISABLE.
* @retval None
*/
void USART_LINCmd(USART_TypeDef* USARTx, FunctionalState NewState)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_FUNCTIONAL_STATE(NewState));
if (NewState != DISABLE)
{
/* Enable the LIN mode by setting the LINEN bit in the CR2 register */
USARTx->CR2 |= USART_CR2_LINEN;
}
else
{
/* Disable the LIN mode by clearing the LINEN bit in the CR2 register */
USARTx->CR2 &= (uint16_t)~((uint16_t)USART_CR2_LINEN);
}
}
/**
* @brief Transmits break characters.
* @param USARTx: where x can be 1, 2, 3, 4, 5 or 6 to select the USART or
* UART peripheral.
* @retval None
*/
void USART_SendBreak(USART_TypeDef* USARTx)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
/* Send break characters */
USARTx->CR1 |= USART_CR1_SBK;
}
/**
* @}
*/
/** @defgroup USART_Group5 Halfduplex mode function
* @brief Half-duplex mode function
*
@verbatim
Hasta ahora no he encontrado un pequeño ejemplo como "Hola mundo" sobre cómo usar esta implementación LIN. Al final, me gustaría transferir los valores de los sensores, pero un ejemplo de transmisión de algunos nubers codificados debería ayudarme.
Editar: Para hacerlo más concreto, una inicialización de los amos y esclavos, así como el envío del número int "1337" resolvería mi problema.