Difference between revisions of "Lesson 3--Microduino "Button Controlled LED""

From Microduino Wiki
Jump to: navigation, search
 
(7 intermediate revisions by 3 users not shown)
Line 4: Line 4:
 
|
 
|
 
==Objective==
 
==Objective==
−
The first two experiments showed you how to use software to control the LED directly. If we add a button,
+
The first two lessons showed you how to use software to control the LED directly. If we add a button  
−
to control the LED light, then realize the combination of hardware and software.
+
to control the LED light, then we can combine the use of both hardware and software.
−
Actually that two experiment use Microduino I/O port as the output to control the LED, if want to use the button,
+
Previously, we used Microduino I/O port as the output to control the LED. So if we want to use a button,
−
how to monitor the input signal of the button?
+
how would we monitor when it is pressed?
−
Today we will take button as an example to show how to use the Microduino as the input.
+
In this lesson, we will use a button as an example to show how to use Microduino as an input.
−
 
 
  
 
==Equipment==
 
==Equipment==
Line 15: Line 14:
 
*'''[[Microduino-FT232R]]'''
 
*'''[[Microduino-FT232R]]'''
 
*Other hardware equipment
 
*Other hardware equipment
−
**Breadboard Jumper           one box 
+
**1x Box of breadboard jumper wires            
−
**Breadboard                one piece 
+
**1x Breadboard                 
−
**LED Light-emitting diodes    one
+
**1x LED (Light-Emitting Diode)
−
**220ohm resistor           one
+
**1x 220ohm resistor          
−
**Button                       one 
+
**1x Button                        
−
**USB Data cable               one
+
**1x USB Data cable            
  
 
==Button==
 
==Button==
 
*Button principle
 
*Button principle
−
[[File:第三课-按键原理.jpg|600px|center|thumb]]
+
[[File:button.jpg|600px|center|thumb]]
−
If use this wrap button making PCB, if bad wiring, it has two pairs of pins available always conduction as a conductor wiring.
 
  
 
*Button connection
 
*Button connection
−
[[File:第三课-按键接法.jpg|600px|center|thumb]]
+
[[File:button connection.jpg|600px|center|thumb]]
−
 
 
−
==Experimental schematic==
 
−
[[File:第三课-原理图.jpg|600px|center|thumb]]
 
−
Using external pulldown resistor, when didn't press, it is low "0", press for high.
 
  
 +
==Experiment Schematic==
 +
[[File:button schematic.jpg|600px|center|thumb]]
 +
Using the external pulldown method, when the button is unpressed, the input to D2 is "LOW". When pressed, it is "HIGH".
  
 
==Program==
 
==Program==
−
*LED display button value
+
*LED is on while button is pressed down
  
 
<source lang="cpp">
 
<source lang="cpp">
 
const int buttonPin = 2;    // Define button input pin
 
const int buttonPin = 2;    // Define button input pin
−
const int ledPin =  13;    //Define LED pin
+
const int ledPin =  11;    //Define LED pin
 
int buttonState = 0;        //Initialize the button value
 
int buttonState = 0;        //Initialize the button value
 
void setup() {
 
void setup() {
 
   pinMode(ledPin, OUTPUT);    //Set the LED pin as output     
 
   pinMode(ledPin, OUTPUT);    //Set the LED pin as output     
−
   pinMode(buttonPin, INPUT); //Set button pin as intpu    
+
   pinMode(buttonPin, INPUT); //Set button pin as input    
 
}
 
}
 
void loop(){
 
void loop(){
 
   buttonState = digitalRead(buttonPin);//Read the value from the buttonPin
 
   buttonState = digitalRead(buttonPin);//Read the value from the buttonPin
 
   if (buttonState == HIGH) {     
 
   if (buttonState == HIGH) {     
−
     digitalWrite(ledPin, HIGH); //If the button input signal is high, the LED will light (LED connect method is that anode connects control pin, cathode connects GND)
+
     digitalWrite(ledPin, HIGH); //If the button input signal is high, the LED will light up
 
   }  
 
   }  
 
   else {
 
   else {
Line 60: Line 57:
 
<source lang="cpp">
 
<source lang="cpp">
 
const int buttonPin = 2;    // Define button input pin
 
const int buttonPin = 2;    // Define button input pin
−
const int ledPin =  13;     
+
const int ledPin =  11;     
  
 
int buttonState = 0;  
 
int buttonState = 0;  
Line 67: Line 64:
 
   pinMode(ledPin, OUTPUT);       
 
   pinMode(ledPin, OUTPUT);       
 
   // pinMode(buttonPin, INPUT); //Set the button pin as input     
 
   // pinMode(buttonPin, INPUT); //Set the button pin as input     
−
   pinMode(buttonPin, INPUT_PULLUP);//Set button pin as interanl pull-up input     
+
   pinMode(buttonPin, INPUT);//Set button pin as input     
 
}
 
}
 
void loop(){
 
void loop(){
 
   buttonState = digitalRead(buttonPin);
 
   buttonState = digitalRead(buttonPin);
−
   if (buttonState ==HIGH) //Use the external pull-down, because the initial state is low, only the press is high, the press was flipped, or not it will blink.
+
   if (buttonState ==HIGH)
 
   {   
 
   {   
−
     delay(200);                     //Short time delay, stabilization
+
     delay(200);                   //Short time delay for stabilization
 
     // delay(1000);              //Long time press
 
     // delay(1000);              //Long time press
−
     // if (buttonState == LOW) //Check still is low
+
     // if (buttonState == LOW)   //Check still is low
−
     led=!led;                   //LED state flip
+
     led=!led;                     //LED state flip
 
   }  
 
   }  
 
   digitalWrite(ledPin, led);   
 
   digitalWrite(ledPin, led);   
 
}
 
}
 
</source>
 
</source>
−
This experiment should be noted the button anti-shake, you can adjust the delay time,
+
 
−
or at both ends of the input signal plus a 104 capacitor, then voltage signal does not mutant.
+
===digitalRead() usage===
−
The detailed button anti-shake information, please refer to：http://www.geek-workshop.com/thread-74-1-1.html
+
Read a pin's value and return HIGH or LOW.
−
===digitalRead（）usage===
 
−
Read a Pin's value and return HIGH or LOW.
 
  
 
==Result==
 
==Result==
−
*Program 1：LED display input button value. High value will light LED, or Put out the LED.
+
*Program 1: LED is on while button is pressed down.
−
*Program 2：Each time you press the button, led voltage flipping once, pay attention to button anti-shake.
+
*Program 2: Each time you press the button, the LED will turn on/off.
 
==Video==
 
==Video==
 
|}
 
|}

Latest revision as of 07:18, 12 September 2016

Language: English  • 中文

Objective

The first two lessons showed you how to use software to control the LED directly. If we add a button to control the LED light, then we can combine the use of both hardware and software. Previously, we used Microduino I/O port as the output to control the LED. So if we want to use a button, how would we monitor when it is pressed? In this lesson, we will use a button as an example to show how to use Microduino as an input.

Equipment

  • Microduino-Core
  • Microduino-FT232R
  • Other hardware equipment
    • 1x Box of breadboard jumper wires
    • 1x Breadboard
    • 1x LED (Light-Emitting Diode)
    • 1x 220ohm resistor
    • 1x Button
    • 1x USB Data cable

Button

  • Button principle
Button.jpg
  • Button connection
Button connection.jpg

Experiment Schematic

Button schematic.jpg

Using the external pulldown method, when the button is unpressed, the input to D2 is "LOW". When pressed, it is "HIGH".

Program

  • LED is on while button is pressed down
const int buttonPin = 2;     // Define button input pin
const int ledPin =  11;     //Define LED pin
int buttonState = 0;        //Initialize the button value
void setup() {
  pinMode(ledPin, OUTPUT);    //Set the LED pin as output    
  pinMode(buttonPin, INPUT);  //Set button pin as input    
}
void loop(){
  buttonState = digitalRead(buttonPin);//Read the value from the buttonPin
  if (buttonState == HIGH) {     
    digitalWrite(ledPin, HIGH); //If the button input signal is high, the LED will light up
  } 
  else {
    digitalWrite(ledPin, LOW); //LED goes out
  }
}
  • LED voltage flip
const int buttonPin = 2;     // Define button input pin
const int ledPin =  11;     

int buttonState = 0; 
boolean led;         //Define LED as boolean（true or false）
void setup() {
  pinMode(ledPin, OUTPUT);      
  // pinMode(buttonPin, INPUT); //Set the button pin as input     
  pinMode(buttonPin, INPUT);//Set button pin as input    
}
void loop(){
  buttonState = digitalRead(buttonPin);
  if (buttonState ==HIGH)
  {  
    delay(200);                   //Short time delay for stabilization
    // delay(1000);               //Long time press
    // if (buttonState == LOW)    //Check still is low
    led=!led;                     //LED state flip
  } 
  digitalWrite(ledPin, led);  
}

digitalRead() usage

Read a pin's value and return HIGH or LOW.

Result

  • Program 1: LED is on while button is pressed down.
  • Program 2: Each time you press the button, the LED will turn on/off.

Video

Retrieved from "https://wiki.microduinoinc.com/index.php?title=Lesson_3--Microduino_%22Button_Controlled_LED%22&oldid=1540"