canbus.c

/* STM32F4-CANBUS canbus.c
 * http://www.eraycanli.com */

#include "commons.h"

#include "canbus.h"
#include "lwipopts.h"
#include "lwip.h"
#include "leds.h"

#include "stm32f4xx_hal_gpio.h"
#include "stm32f4xx_hal_can.h"


uint8_t CAN1dataReceivedFlag;


CAN_HandleTypeDef HCAN1;
CanTxMsgTypeDef TxMessage; /* Tx message struct */
CanRxMsgTypeDef RxMessage; /* Rx message struct */


void InitializeCANBUS1()
{
    GPIO_InitTypeDef GPIO_InitStruct;
    CAN_FilterConfTypeDef CAN_FilterStruct;


    __HAL_RCC_CAN1_CLK_ENABLE(); /* Enable CANBUS-1 clock */

    __GPIOD_CLK_ENABLE(); /* Enable GPIOD clock */


    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP; /* Alternate Function Push-Pull mode */
    GPIO_InitStruct.Pull = GPIO_NOPULL; /* No resistor */
    GPIO_InitStruct.Speed = GPIO_SPEED_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF9_CAN1; /* Alternate pin function: AF9 / CAN1 */
    GPIO_InitStruct.Pin = GPIO_PIN_1 | GPIO_PIN_0; /* PD1(CAN1_TX) & PD0(CAN1_RX) */
    HAL_GPIO_Init(GPIOD, &GPIO_InitStruct); /* Initialize registers */


    HCAN1.Instance = CAN1;
    HCAN1.pTxMsg = &TxMessage; /* Pointer to CAN Tx message */
    HCAN1.pRxMsg = &RxMessage; /* Pointer to CAN Rx message */
    HCAN1.Init.Prescaler = 19; /* Time quanta prescaler (tq = (Prescaler+1)/42MHz) */
    HCAN1.Init.Mode = CAN_MODE_NORMAL; /* Normal communication mode */
    HCAN1.Init.SJW = CAN_SJW_4TQ; /* 4 time-quanta re-sync jump width */
    HCAN1.Init.BS1 = CAN_BS1_9TQ; /* 9 tq before sampling point */
    HCAN1.Init.BS2 = CAN_BS2_8TQ; /* 8 tq after sampling point (before end) */
    HCAN1.Init.TTCM = DISABLE; /* Time-triggered communication */
    HCAN1.Init.ABOM = DISABLE; /* Automatic bus-off management */
    HCAN1.Init.AWUM = DISABLE; /* Automatic wake-up mode */
    HCAN1.Init.NART = DISABLE; /* Non-automatic retransmission mode */
    HCAN1.Init.RFLM = DISABLE; /* Receive FIFO locked mode */
    HCAN1.Init.TXFP = DISABLE; /* Transmit FIFO priority */
    HAL_CAN_Init(&HCAN1); /* Init CAN1 registers */


    CAN_FilterStruct.FilterIdHigh = 0x0000; /* Upper 16bit filter ID */
    CAN_FilterStruct.FilterIdLow = 0x0000; /* Filter lower 16bit ID */
    CAN_FilterStruct.FilterMaskIdHigh = 0x0000; /* Upper 16bit filter mask */
    CAN_FilterStruct.FilterMaskIdLow = 0x0000; /* Lower 16bit filter mask */
    CAN_FilterStruct.FilterFIFOAssignment = CAN_FILTER_FIFO0; /* Which FIFO will be assigned to filter */
    CAN_FilterStruct.FilterNumber = 0;
    CAN_FilterStruct.FilterMode = CAN_FILTERMODE_IDMASK; /* Identifier mask mode */
    CAN_FilterStruct.FilterScale = CAN_FILTERSCALE_32BIT; /* 32bit ID filter */
    CAN_FilterStruct.FilterActivation = ENABLE; /* Enable this filter */
    CAN_FilterStruct.BankNumber = 14; /* Start slave bank filter (?) */
    HAL_CAN_ConfigFilter(&HCAN1, &CAN_FilterStruct); /* Initialize filter */


    HAL_NVIC_SetPriority(CAN1_RX0_IRQn, 1, 1); /* Set CAN1 Rx interrupt priority to 1-1 */
    HAL_NVIC_EnableIRQ(CAN1_RX0_IRQn); /* Enable CAN1 Rx Interrupt */

    __HAL_CAN_ENABLE_IT(&HCAN1, CAN_IT_FMP0); /* Enable 'message pending in FIFO0' interrupt */

    HCAN1.pTxMsg->StdId = 0x14; /* Standard ID of this device */
    HCAN1.pTxMsg->ExtId = 0x01; /* Extended ID */
    HCAN1.pTxMsg->RTR = CAN_RTR_DATA; /* Remote transmission request:data 0x00000000 */
    HCAN1.pTxMsg->IDE = CAN_ID_STD; /* Identifier type: standard 0x00000000 */

    return;
}


void CAN1SendMessage(uint8_t length, uint8_t *data)
{
    HCAN1.pTxMsg->DLC = length; /* Specify the data length */

    uint8_t d;

    for(d = 0; d < length; ++d)
    {
        HCAN1.pTxMsg->Data[d] = *(data + d); /* Write every byte to Data[] variable */
    }

    HAL_CAN_Transmit(&HCAN1, 3000); /* Transmit the packet */

    return;
}


/* CAN1 Rx FIFO0 interrupt service routine */
void CAN1_RX0_IRQHandler()
{
    if(HAL_CAN_Receive(&HCAN1, 0, 5000) == HAL_OK) /* Packet received from CANBUS successfully */
    {
        if(RxMessage.Data[0] == 0xAA && RxMessage.Data[2] == 0x55) /* Sync bytes are correct */
        {
            LedState(LED_BLUE, 1); /* Blue LED ON */

            CAN1dataReceivedFlag = 1; /* Set data received flag */
        }
    }

    return;
}


/* canbus.c */