Question

我正在尝试使用I2C将来自NVIDIA Jetson TX1的数据信号发送到Arduino Uno，然后让Arduino发回数据。最终将从传感器收集回发的Arduino数据。 Arduino通过multiplexer连接到Jetson。

当我从Jetson发送一个字符串时，Arduino接收并正确显示它在串行输出上，但是Jetson收到的信号似乎是两个随机字符，其后32个字节的其余部分是255.还有空格似乎不起作用，但这不是一个问题，更多的只是观察。

这是我在Jetson上使用的代码

#include <iostream>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#include <string>
#include <stdio.h>

using namespace std;

int addr1 = 0x40;
int addr2 = 0x04;
int file_i2c;
int file_i2c2;
const int numBytes = 32;
char *filename = (char*)"/dev/i2c-1";
unsigned char buffer[numBytes] = {0};

bool writeStream(int file_i2c, string output) {
  if(write(file_i2c, output.c_str(), output.length()) != output.length()) {
    printf("\tFailed to write to the i2c bus.\n");
  }
  return true;
}

int main() {
  //Open i2c bus
  if((file_i2c = open(filename, O_RDWR)) < 0) {
    printf("\tFailed to open the i2c bus\n");
    //exit(1);
  }
  if(ioctl(file_i2c, I2C_SLAVE, addr2) < 0) {
    printf("\tFailed to acquire bus access and/or talk to slave.\n");
    //exit(1);
  }
  string input;
  cin >> input;
  writeStream(file_i2c, input);
  cin >> input; //Using this as a breakpoint
  if(ioctl(file_i2c, I2C_SLAVE, addr1) < 0) {
    printf("\tFailed to acquire bus access and/or talk to slave.\n");
    //exit(1);
  }
  if(read(file_i2c, buffer,numBytes) != numBytes) {
    printf("\tFailed to read from the i2c bus.");
  }
  cout << "Data read:\n";
  for (int i = 0; i < numBytes; i++) {
    cout << buffer[i] << "\t" << (int)buffer[i] << endl;
  }
  cout << "End!\n";
  return 0;
}

这是我的Arduino代码：

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_TSL2591.h>

#define TCAADDR 0x70

int clockSpeed = 100000;
char myOutput[32] = {0};
char sent[32] = {0};

void setup() {
  digitalWrite(6, HIGH);
  Wire.begin(0x04);
  Wire.setClock(clockSpeed);
  Wire.onReceive(receiveEvent);
  Serial.begin(9600);
  tcaselect(1);
}

void loop() {
  delay(100);
  if(strcmp(myOutput, sent)) {
    send(myOutput);
    strncpy(sent, myOutput, 32);
  }
}

void tcaselect(uint8_t i) {
  if (i > 7) return;
  Wire.beginTransmission(TCAADDR);
  Wire.write(1 << i);
  Wire.endTransmission();
}

void receiveEvent() {
  char c[32] = {0};
  int count = 0;
  while (0 < Wire.available()) {
    c[count] = Wire.read();
    Serial.print(c[count]);
    count++;
  }
  Serial.println();
  strncpy(myOutput, c, 32);
}

void send(char c[]) {
  Wire.beginTransmission(0x40);
  Serial.print("Sending signal:\t");
  Wire.write(c);
  Serial.print(c);
  Serial.println();
  Wire.endTransmission();
}

Arduino和NVIDIA Jetson之间的I2C通信问题

0 个答案: