为什么我收到 Raspberry pi mcp3008 C++ 错误？

Question

我想在树莓派 4 上设置 mcp3008。我拿了这个代码

#include <wiringPi.h>
#include <stdio.h>
#include <unistd.h>


int readMCP3008(int &channel);


#define CHANNELS 4
#define SPI_CHANNEL 0
#define REFERENCE_VOLTAGE 5.0


int readMCP3008(int channel) {
    if (channel < 0 || channel >= CHANNELS) {
        fprintf(stderr, "Invalid channel.\n");
        return -1;
    }


    unsigned char buffer[3];
    buffer[0] = 0b11000000 | ((channel & 0x07) << 3);
    buffer[1] = 0;
    buffer[2] = 0;


    wiringPiSPIDataRW(SPI_CHANNEL, buffer, 3);


    int result = ((buffer[0] & 0x01) << 9) | (buffer[1] << 1) | ((buffer[2] & 0x80) >> 7);
    return result;
}

int main() {
    if (wiringPiSetup() == -1) {
        fprintf(stderr, "Error initializing WiringPi.\n");
        return 1;
    }


    int spiHandle = wiringPiSPISetup(SPI_CHANNEL, 1000000); // Default SPI speed
    if (spiHandle == -1) {
        fprintf(stderr, "Error initializing SPI.\n");
        return 1;
    }


    FILE *file = fopen("mcp3008_data.txt", "w");
    if (file == NULL) {
        fprintf(stderr, "Error opening file for writing.\n");
        return 1;
    }

   
    const int numSamples = 100; // Adjust as needed
    for (int sample = 0; sample < numSamples; sample++) {
        double value0 = (readMCP3008(0) * REFERENCE_VOLTAGE / 1023.0) - 1.5;
        double value1 = (readMCP3008(1) * REFERENCE_VOLTAGE / 1023.0) - 1.5;
        double value2 = (readMCP3008(2) * REFERENCE_VOLTAGE / 1023.0) - 1.5;
        double value3 = (readMCP3008(3) * REFERENCE_VOLTAGE / 1023.0) - 1.5;

        fprintf(file, "%.2f,%.2f,%.2f,%.2f", value0, value1, value2, value3);

        fprintf(file, "\n");

 
        usleep(100000); // 100,000 microseconds = 100 milliseconds (adjust as needed)
    }

   
    fclose(file);

    return 0;
}

但它给出了这个错误：

`g++ -Wall -o "mcp3008_read" "mcp3008_read.cpp" (/home/*/Desktop dizininde)
mcp3008_read.cpp: In function ‘int readMCP3008(int)’:
mcp3008_read.cpp:27:5: error: ‘wiringPiSPIDataRW’ was not declared in this scope
   27 |     wiringPiSPIDataRW(SPI_CHANNEL, buffer, 3);
      |     ^~~~~~~~~~~~~~~~~
mcp3008_read.cpp: In function ‘int main()’:
mcp3008_read.cpp:41:21: error: ‘wiringPiSPISetup’ was not declared in this scope; did you mean ‘wiringPiSetup’?
   41 |     int spiHandle = wiringPiSPISetup(SPI_CHANNEL, 1000000); // Default SPI speed
      |                     ^~~~~~~~~~~~~~~~
      |                     wiringPiSetup
`

我从论坛上看到了几个答案，它们将函数定义为我尝试过的全局函数，但可能我尝试错了，chatgpt 说我没有下载 WiringSPI 库，但我下载了。我检查了所有连接，mcp3008 在 python 上运行。我不知道如何修复这个错误。

Answer 1

检查标头：https://github.com/WiringPi/WiringPi/blob/master/wiringPi/wiringPiSPI.h

头文件

wiringPi.h

没有包含

wiringPiSPI.h

，需要你自己做。