【MCX-N947-BRK板卡试用】-2-CAN收发测试

SensorYoung · 发表于 2024-4-1 20:14:45

本帖最后由 SensorYoung 于 2024-4-2 09:04 编辑

上一篇：【MCX-N947-BRK板卡试用】-1-CAN回环模式测试

https://www.nxpic.org.cn/module/forum/forum.php?mod=viewthread&tid=803085&fromuid=349725

本次将配合TJA1050 CAN收发器，以及简易USB CAN来测试一下MCX-N947 BRK的CAN收发功能。
根据Reference Manual，P1_10与P1_11的ALT11功能为CAN收发：

pin_mux.c里面增加CAN0_TX CAN0_RX引脚功能的定义：

/*
* CAN TX : P1_10
*/
const port_pin_config_t port1_10_pinC3_config = {/* Internal pull-up/down resistor is disabled */
kPORT_PullDisable,
/* Low internal pull resistor value is selected. */
kPORT_LowPullResistor,
/* Fast slew rate is configured */
kPORT_FastSlewRate,
/* Passive input filter is disabled */
kPORT_PassiveFilterDisable,
/* Open drain output is disabled */
kPORT_OpenDrainEnable,
/* Low drive strength is configured */
kPORT_LowDriveStrength,
/* Pin is configured as CAN0_TXD */
kPORT_MuxAlt11,
/* Digital input enabled */
kPORT_InputBufferEnable,
/* Digital input is not inverted */
kPORT_InputNormal,
/* Pin Control Register fields [15:0] are not locked */
kPORT_UnlockRegister};
/* PORT1_10 (pin C3) is configured as CAN0_TXD */
PORT_SetPinConfig(PORT1, 10U, &port1_10_pinC3_config);
/*
* CAN RX : P1_11
*/
const port_pin_config_t port1_11_pinD3_config = {/* Internal pull-up/down resistor is disabled */
kPORT_PullDisable,
/* Low internal pull resistor value is selected. */
kPORT_LowPullResistor,
/* Fast slew rate is configured */
kPORT_FastSlewRate,
/* Passive input filter is disabled */
kPORT_PassiveFilterDisable,
/* Open drain output is disabled */
kPORT_OpenDrainEnable,
/* Low drive strength is configured */
kPORT_LowDriveStrength,
/* Pin is configured as CAN0_RXD */
kPORT_MuxAlt11,
/* Digital input enabled */
kPORT_InputBufferEnable,
/* Digital input is not inverted */
kPORT_InputNormal,
/* Pin Control Register fields [15:0] are not locked */
kPORT_UnlockRegister};
/* PORT1_11 (pin D3) is configured as CAN0_RXD */
PORT_SetPinConfig(PORT1, 11U, &port1_11_pinD3_config);

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相比于上一篇回环模式测试，这次需要在真实的CAN总线上收发报文，因此要注释掉下面这句：

//flexcanConfig.enableLoopBack = true;

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报文接收过滤器设置为接收CAN id 0x125的报文：

/* Setup Rx Message Buffer. */
mbConfig.format = kFLEXCAN_FrameFormatStandard;
mbConfig.type = kFLEXCAN_FrameTypeData;
mbConfig.id = FLEXCAN_ID_STD(0x125);
#if (defined(USE_CANFD) && USE_CANFD)
FLEXCAN_SetFDRxMbConfig(EXAMPLE_CAN, RX_MESSAGE_BUFFER_NUM, &mbConfig, true);
#else
FLEXCAN_SetRxMbConfig(EXAMPLE_CAN, RX_MESSAGE_BUFFER_NUM, &mbConfig, true);
#endif
/* Setup Tx Message Buffer. */
#if (defined(USE_CANFD) && USE_CANFD)
FLEXCAN_SetFDTxMbConfig(EXAMPLE_CAN, TX_MESSAGE_BUFFER_NUM, true);
#else
FLEXCAN_SetTxMbConfig(EXAMPLE_CAN, TX_MESSAGE_BUFFER_NUM, true);
#endif
/* Create FlexCAN handle structure and set call back function. */
FLEXCAN_TransferCreateHandle(EXAMPLE_CAN, &flexcanHandle, flexcan_callback, NULL);
/* Start receive data through Rx Message Buffer. */
rxXfer.mbIdx = (uint8_t)RX_MESSAGE_BUFFER_NUM;
#if (defined(USE_CANFD) && USE_CANFD)
rxXfer.framefd = &rxFrame;
(void)FLEXCAN_TransferFDReceiveNonBlocking(EXAMPLE_CAN, &flexcanHandle, &rxXfer);
#else
rxXfer.frame = &rxFrame;
(void)FLEXCAN_TransferReceiveNonBlocking(EXAMPLE_CAN, &flexcanHandle, &rxXfer);
#endif

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循环主体：

while (true)
{
/* Delay 1000 ms */
SysTick_DelayTicks(1000U);
GPIO_PortToggle(BOARD_LED_GPIO, 1u << BOARD_LED_GPIO_PIN);
if(mycnt%60 == 0){
SEGGER_RTT_printf(0,"\r\nmycnt= %d\r\n", mycnt);
txFrame.dataByte7 = mycnt/60;
(void)FLEXCAN_TransferSendNonBlocking(EXAMPLE_CAN, &flexcanHandle, &txXfer);
/* Waiting for Tx Message finish. */
while (!txComplete)
{
};
SEGGER_RTT_printf(0,"\r\n==FlexCAN Transfer Done -- Finish.==\r\n");
}
mycnt++;
if(rxComplete){
rxComplete = false;
SEGGER_RTT_printf(0,"\r\n CAN Rx Done\r\n");
SEGGER_RTT_printf(0,"\r\nReceived message from MB%d\r\n", RX_MESSAGE_BUFFER_NUM);
//SEGGER_RTT_printf(0,"EXAMPLE_CAN_CLK_FREQ = %u MHz, CAN BUS bitRate = %uk bps\r\n", EXAMPLE_CAN_CLK_FREQ/1000000, (flexcanConfig.bitRate)/1000);
SEGGER_RTT_printf(0,"rx frame CanID = 0x%x\r\n", (rxFrame.id)>>18);
SEGGER_RTT_printf(0,"rx word0 = 0x%x\r\n", rxFrame.dataWord0);
SEGGER_RTT_printf(0,"rx word1 = 0x%x\r\n", rxFrame.dataWord1);
SEGGER_RTT_printf(0,"\r\n==FlexCAN Receive Done -- Finish.==\r\n");
(void)FLEXCAN_TransferReceiveNonBlocking(EXAMPLE_CAN, &flexcanHandle, &rxXfer);
}
}