Question

我正在开发一个涉及Arduino Uno和Raspberry Pi之间I2C通信的项目。我试图从Pi向Arduino发送字符串数据，反之亦然。

这是我的Arduino代码

#include <Wire.h>
#include <Arduino.h>
#define SLAVE_ADDRESS 0x12

int flag_int_to_send_to_PI = 0;

int flag_int_received_from_PI = 0;

char data_to_send_PI[] = "hello PI"; 

String data_recieved_from_pi = "";

void setup() {

   Wire.begin(SLAVE_ADDRESS);

   Wire.onReceive(receiveData);

   Wire.onRequest(sendData);

   Serial.begin(9600);

   flag_int_to_send_to_PI = 1;


}

void loop() {
}



void receiveData(int byteCount) {

    while(Wire.available()) 
    {
        flag_int_received_from_PI = Wire.read();

        if(flag_int_received_from_PI == 1)
        {
           Serial.println("PI Wants data[].");

           flag_int_to_send_to_PI= 3;


        }  

        if(flag_int_received_from_PI == 3)
        {
            Serial.println("PI Wants To say its ok.");

            //reading a string from pi: Here (How ?)
              while( Wire.available())
              {
                data_recieved_from_pi += (char)Wire.read();

              }

              Serial.print("Data Received From PI:");

              Serial.println(data_recieved_from_pi);

              data_recieved_from_pi = "";
        }


    }
}

void sendData() {

    if(flag_int_to_send_to_PI == 1)
    {
        Serial.println("Conversation begin : sending 1 to PI");

        Wire.write(flag_int_to_send_to_PI);
    }

    if(flag_int_to_send_to_PI == 3) { 

        Wire.write(data_to_send_PI);
    }

    flag_int_to_send_to_PI = 0;

}

以下是Raspberry Pi代码：

from smbus import SMBus
import time
bus = SMBus(1)
slaveAddress = 0x12
data_received_from_Arduino = ""
data_to_send_to_Arduino = "Hello Uno"

def StringToBytes(val):
    retVal = []
    for c in val:
            retVal.append(ord(c))
    return retVal


while(1):
    try:
        x = bus.read_byte(slaveAddress)

      if (x == 1):
           print(x)
           bus.write_byte(slaveAddress,1)
           time.sleep(0.2)
           data_received_from_Arduino = bus.read_i2c_block_data(slaveAddress, 0,12)
           print(data_received_from_Arduino)
           bus.write_byte(slaveAddress,3)
           print(StringToBytes(data_to_send_to_Arduino))
           bus.write_i2c_block_data(slaveAddress, 0x00,StringToBytes(data_to_send_to_Arduino))

这是串口和控制台输出。

Arduino串行输出：

Conversation begin : sending 1 to PI
PI Wants data[].
PI Wants To say its ok.
Data Received From PI:

Raspberry Pi控制台：

1
[0, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255]
[72, 101, 108, 108, 111, 32, 85, 110, 111]

它是如何工作的？

Arduino向Pi发送1以启动两次通信 Pi发回1确认它 Arduino将数据串发送给Pi Pi接收数据并向Arduino发回3号说它没问题。（但没有好的）然后Pi将数据字符串发送到Arduino，我不知道如何在Arduino端阅读，尽管我尝试过。

我的问题：

为什么Raspberry Pi在缓冲区的任何地方都接收255？ Arduino如何获得从Pi发送的字节数组？

使用I2c接口在{Arduino和Raspberry PI之间发送和接收字符串数据

0 个答案: