Question

我有一个简单的程序：

void setup() {
  Serial.begin(9600);
}

void loop() {
  int x = 0;
  Serial.print(x++);
}

每当我试图查看串行日志时都没有显示，我做错了什么。我正在使用Arduino Leonardo并且草图编译和上传。

-----------------更新1 ---------------

我真正试图让控制台打印出来的是以下代码。然而，由于它失败了，我做了一个简短的程序：

// SparkFun Soil Moisture Sensor and Serial LCD example 1
// By Sarah Al-Mutlaq 2015
// Sketch reads sensor and desplays level and whether soil is wet or dry

// Use the softwareserial library to create a new "soft" serial port
// for the display. This prevents display corruption when uploading code.
#include <SoftwareSerial.h>

// Attach the serial display's RX line to digital pin 2
SoftwareSerial mySerial(3,2); // pin 2 = TX, pin 3 = RX (unused)


// Here we are setting up some water thersholds that we will 
// use later. Note that you will need to change these to match
// your soil type and environment. 

int thresholdUp = 400;
int thresholdDown = 250;

// We are setting up the pin A0 on the redboard to be our sensor
// pin input:

int sensorPin = A0;


void setup(){
  mySerial.begin(9600); // set up serial port for 9600 baud (speed)
  delay(500); // wait for display to boot up
}

void loop(){
  // Here we are declaring a string, which are lines of words,
  // and we want DisplayWords to be the words displayed on
  // the LCD screen, which will change based on whether the soil
  // wet or dry based on our threshold values above.
  String DisplayWords;

  // We need to set up a pin to get the value that the soil 
  // moisture sensor is outputting, so sensorValue will get the
  // analog value from the sensor pin A0 on the redboard that we 
  // set up earlier.

  int sensorValue;
  sensorValue = analogRead(sensorPin);

  // move cursor to beginning of first line on LCD:
  mySerial.write(254); 
  mySerial.write(128);

  // clear display:
  mySerial.write("                "); 
  mySerial.write("                ");

  // move cursor to beginning of first line of the LCD screen:
  mySerial.write(254); 
  mySerial.write(128);

  //Write what we want to desplay on the screen:
  mySerial.write("Water Level: ");
  mySerial.print(sensorValue); //Using .print instead of .write for values

  // Now we are going to check if the water level is below a 
  // out thresholdDown value we set earlier, and if it is have 
  // words "Dry, Water it!" display one column over on the first 
  // row:

  if (sensorValue <= thresholdDown){
    // move cursor to beginning of second line on LCD:
    mySerial.write(254); 
    mySerial.write(192);

    DisplayWords = "Dry, Water it!";
    mySerial.print(DisplayWords);

  // If the value is not below our thresholdDown value we want to 
  // check if it is above our thresholdUp value, and if it is 
  // change the display words to "Wet, Leave it!":



  } else if (sensorValue >= thresholdUp){
    // move cursor to beginning of second line on LCD:
    mySerial.write(254); 
    mySerial.write(192);

    DisplayWords = "Wet, Leave it!";
    mySerial.print(DisplayWords);

  // Otherwise if it is inbetween the two values we want it to 
  // the display it had, so if our soil was really wet and drying 
  // the words would only change to "Dry, Water it!" when it got to the lower threshold
  // (thresholdDown), but if it was dry and getting wetter the words
  // would only change to "Wet, Leave it!" when it got to the upper 
  // threshold (thresholdUp_):

  } else {
    // move cursor to beginning of second line on LCD:
    mySerial.write(254); 
    mySerial.write(192);

    mySerial.print(DisplayWords);
  }

  delay(500); //wait for half a second, so it is easier to read
}

Answer 1

我现在看到你正在控制一个显示器。使用这些并不像将字节发送到终端仿真器。他们必须得到控制。控制这些串行显示通常包括发送一些初始化命令，这些命令通常（但不总是）类似于不同的显示器，前提是它们具有相同的显示控制器。

我不知道你正在使用什么显示器部件，但我冒昧地说缺少一些初始化命令。 500ms延迟通常是其中的一部分，但在发送光标定位命令之前，请检查文档中是否需要发送的任何其他init命令。

通常你必须发送一个初始字节命令将显示器置于命令模式，发送一些配置命令，然后退出命令模式以实际使用显示器。如果它是基于Hitachi 44780的显示器，您可以查看44780 datasheet处的数据表。

无法使Serial.print工作

1 个答案: