1 int main(void)  2 {  3     tCANMsgObject sCANMessage;  4     unsigned char ucMsgData[4];  5   6     //  7     // Set the clocking to run directly from the external crystal/oscillator.  8     // TODO: The SYSCTL_XTAL_ value must be changed to match the value of the  9     // crystal on your board. 10     // 11     SysCtlClockSet(SYSCTL_SYSDIV_2_5 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | 12                    SYSCTL_XTAL_16MHZ); 13  14     // 15     // Set up the serial console to use for displaying messages.  This is 16     // just for this example program and is not needed for CAN operation. 17     // 18     InitConsole(); 19  20     // 21     // For this example CAN0 is used with RX and TX pins on port D0 and D1. 22     // The actual port and pins used may be different on your part, consult 23     // the data sheet for more information. 24     // GPIO port D needs to be enabled so these pins can be used. 25     // TODO: change this to whichever GPIO port you are using 26     // 27     SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE); 28  29     // 30     // Configure the GPIO pin muxing to select CAN0 functions for these pins. 31     // This step selects which alternate function is available for these pins. 32     // This is necessary if your part supports GPIO pin function muxing. 33     // Consult the data sheet to see which functions are allocated per pin. 34     // TODO: change this to select the port/pin you are using 35     // 36     GPIOPinConfigure(GPIO_PE4_CAN0RX); 37     GPIOPinConfigure(GPIO_PE5_CAN0TX); 38  39     // 40     // Enable the alternate function on the GPIO pins.  The above step selects 41     // which alternate function is available.  This step actually enables the 42     // alternate function instead of GPIO for these pins. 43     // TODO: change this to match the port/pin you are using 44     // 45     GPIOPinTypeCAN(GPIO_PORTE_BASE, GPIO_PIN_4 | GPIO_PIN_5); 46  47     // 48     // The GPIO port and pins have been set up for CAN.  The CAN peripheral 49     // must be enabled. 50     // 51     SysCtlPeripheralEnable(SYSCTL_PERIPH_CAN0); 52  53     // 54     // Initialize the CAN controller 55     // 56     CANInit(CAN0_BASE); 57  58     // 59     // Set up the bit rate for the CAN bus.  This function sets up the CAN 60     // bus timing for a nominal configuration.  You can achieve more control 61     // over the CAN bus timing by using the function CANBitTimingSet() instead 62     // of this one, if needed. 63     // In this example, the CAN bus is set to 500 kHz.  In the function below, 64     // the call to SysCtlClockGet() is used to determine the clock rate that 65     // is used for clocking the CAN peripheral.  This can be replaced with a 66     // fixed value if you know the value of the system clock, saving the extra 67     // function call.  For some parts, the CAN peripheral is clocked by a fixed 68     // 8 MHz regardless of the system clock in which case the call to 69     // SysCtlClockGet() should be replaced with 8000000.  Consult the data 70     // sheet for more information about CAN peripheral clocking. 71     // 72  73     sysclk = SysCtlClockGet(); 74     CANBitRateSet(CAN0_BASE, sysclk, 500000); 75  76     // 77     // Enable interrupts on the CAN peripheral.  This example uses static 78     // allocation of interrupt handlers which means the name of the handler 79     // is in the vector table of startup code.  If you want to use dynamic 80     // allocation of the vector table, then you must also call CANIntRegister() 81     // here. 82     // 83     // CANIntRegister(CAN0_BASE, CANIntHandler); // if using dynamic vectors 84     // 85     CANIntEnable(CAN0_BASE, CAN_INT_MASTER | CAN_INT_ERROR | CAN_INT_STATUS); 86  87     CANRetrySet(CAN0_BASE, false); 88     // 89     // Enable the CAN interrupt on the processor (NVIC). 90     // 91     IntEnable(INT_CAN0); 92  93     // 94     // Enable the CAN for operation. 95     // 96     CANEnable(CAN0_BASE); 97  98     // 99     // Initialize the message object that will be used for sending CAN100     // messages.  The message will be 4 bytes that will contain an incrementing101     // value.  Initially it will be set to 0.102     //103     *(unsigned long *)ucMsgData = 0;104     sCANMessage.ulMsgID = 0x220;                    // CAN message ID105     sCANMessage.ulMsgIDMask = 0;                    // no mask needed for TX106     sCANMessage.ulFlags = MSG_OBJ_TX_INT_ENABLE;    // enable interrupt on TX107     sCANMessage.ulMsgLen = sizeof(ucMsgData);       // size of message is 4108     sCANMessage.pucMsgData = ucMsgData;             // ptr to message content109 110     ucMsgData[0] = 0x12;111     ucMsgData[1] = 0x34;112     ucMsgData[2] = 0x56;113     ucMsgData[3] = 0x78;114     //115     // Enter loop to send messages.  A new message will be sent once per116     // second.  The 4 bytes of message content will be treated as an unsigned117     // long and incremented by one each time.118     //119     for(;;)120     {121         //122         // Print a message to the console showing the message count and the123         // contents of the message being sent.124         //125         UARTprintf("Sending msg: 0x%02X %02X %02X %02X",126                    ucMsgData[0], ucMsgData[1], ucMsgData[2], ucMsgData[3]);127 128         //129         // Send the CAN message using object number 1 (not the same thing as130         // CAN ID, which is also 1 in this example).  This function will cause131         // the message to be transmitted right away.132         //133         CANMessageSet(CAN0_BASE, 1, &sCANMessage, MSG_OBJ_TYPE_TX);134 135         //136         // Now wait 1 second before continuing137         //138         SimpleDelay();139 140         //141         // Check the error flag to see if errors occurred142         //143         if(g_bErrFlag)144         {145             UARTprintf(" error - cable connected?\n");146         }147         else148         {149             //150             // If no errors then print the count of message sent151             //152             UARTprintf(" total count = %u\n", g_ulMsgCount);153         }154 155         //156         // Increment the value in the message data.157         //158         //(*(unsigned long *)ucMsgData)++;159     }160 161     //162     // Return no errors163     //164     return(0);165 }

 1 import csv 2 import matplotlib 3 import matplotlib.pyplot as plt 4 import matplotlib.collections as collections 5 from matplotlib.ticker import MultipleLocator 6 import numpy as np 7 import pandas as pd 8  9 ax = plt.subplot()10 #將x主刻度標簽設置為125的倍數11 xmajorLocator = MultipleLocator(125) 12 ax.xaxis.set_major_locator(xmajorLocator)13 #y軸數據14 raw_canh = pd.read_csv("canh.csv")15 raw_canl = pd.read_csv("canl.csv")16 #x軸數據17 t = np.arange(130, 12000, 1)18 ax.plot(t, raw_canh[130:12000], raw_canl[130:12000])19 ax.xaxis.grid(True)20 21 plt.show()