eDIY - 最简单又最便宜的Arduino

Thursday, 06 December 2012 16:33

最简单又最便宜的Arduino

这里我们打造一个US3.00的Arduino，只是使用一个ATTiny85(ATTiny45，ATTiny44都可以)，所以称它为Tiny Arduino。

Tiny Arduino只有八个接脚（Pin)，Pin4为接地(Gnd)，Pin8为5V(Vcc)，Pin1为复位(Reset)，Pin2和Pin3原本用来连接Crystal，为了要尽量用完全部IO，所以使用了内部振荡(RC Oscillator)，因此Tiny Arduino共有五个IO。以下是Tiny Arduino的功能。

五个IO，各个IO可以设成输入(Input)或者输出(Output)
其中两个IO可以设成PWM
其中三个IO可以设成Analog输入

如果功能不足够，可以通过I2C对外扩展

材料

1 x 5V电源power supply
1 x Breadboard (Project board)
1 x ATTiny85 （这就是我们的Tiny Arduino)
1 x Arduino duemilanove(用来上传Sketch至ATTiny85)
1 x 10 uF 电容器capacitors（防止Arduino duemilanove自动复位）
5 x 光二极管LED
5 x 电阻器Resistors
以及少许Wire

由于ATTiny85 本身没有串行(Serial)接口，所以我们必须借用外面的编译器来上载Sketch，这里我们使用Arduino duemilanove上载Sketch至ATTiny85。因此我们必须把Arduino duemilanove设成编译器（in-system programmer）简称为ISP。

将Arduino duemilanove连接至电脑
打开Arduino 软件，这里我使用arduino-0023
按File>Examples>ArduinoISP

按Tools>Board>Arduino Duemilanove or Nano w/ATmega328 或者Arduino UNO

单击Upload icon开始上载Sketch至Arduino duemilanove
现在你的Arduino duemilanove变成ISP编译器了

你必须添加plugin支持ATtiny85：

下载ATtiny85 Plugin
找出Arduino sketchbook文件夹，按File>Peferences，我的sketchbook是在D:\My Documents\Arduino如图下：

如果sketchbook文件夹里没有Hardware文件夹，就自己创建一个
把已经下载的ATtiny85 Plugin解压到Hardware文件夹里。如图下

完成这步骤后，你会在Tools>Board看到ATtiny85 (w/Arduino as ISP)

连接Arduino duemilanove至ATTiny85，接法如图下：

这里设计一个跑马灯电路图，五粒LED顺序地跑。

按File>New
复制以下跑马灯源码
按Tools>Board>ATtiny85 (w/Arduino as ISP)

单击Upload icon开始上载Sketch至ATtiny85

跑马灯源码，只占用了8KByte Flash Memory中的804Byte

// The sketch demonstrate a 5 channel running light using ATTiny45/85 micro controller

#define CH1 0 // ATTiny45/85 PIN5
#define CH2 1 // ATTiny45/85 PIN6
#define CH3 2 // ATTiny45/85 PIN7
#define CH4 3 // ATTiny45/85 PIN2
#define CH5 4 // ATTiny45/85 PIN3

long interval = 1000; // set the LED blink speed (1000ms= one second)

void setup()
{
pinMode(CH1, OUTPUT); // set CH1 as output
pinMode(CH2, OUTPUT); // set CH2 as output
pinMode(CH3, OUTPUT); // set CH3 as output
pinMode(CH4, OUTPUT); // set CH4 as output
pinMode(CH5, OUTPUT); // set CH5 as output
}

void loop() {
digitalWrite(CH1, HIGH); // set the LED on
delay(interval); // wait for a second
digitalWrite(CH1, LOW); // set

digitalWrite(CH2, HIGH); // set the LED on
delay(interval); // wait for a second
digitalWrite(CH2, LOW); // set the LED off

digitalWrite(CH3, HIGH); // set the LED on
delay(interval); // wait for a second
digitalWrite(CH3, LOW); // set the LED off

digitalWrite(CH4, HIGH); // set the LED on
delay(interval); // wait for a second
digitalWrite(CH4, LOW); // set the LED off

digitalWrite(CH5, HIGH); // set the LED on
delay(interval); // wait for a second
digitalWrite(CH5, LOW); // set the LED off
}

比较复杂的Sketch，占用了8KByte Flash Memory中的1508Byte

#define MAX_CHANNEL 5
#define CH1 0 // ATTiny45/85 PIN5
#define CH2 1 // ATTiny45/85 PIN6
#define CH3 2 // ATTiny45/85 PIN7
#define CH4 3 // ATTiny45/85 PIN2
#define CH5 4 // ATTiny45/85 PIN3

int Channel[MAX_CHANNEL] = {CH1, CH2, CH3, CH4, CH5};

long interval = 500; //speed = 0.5 second

void setup() {
//Serial.begin(9600);
for (byte i=0; i<MAX_CHANNEL; i++) {
pinMode(Channel[i], OUTPUT); // declare all channel as output
}

allChannelOn(); //turn on all LED for one second during startup
delay(1000);
}

void loop()
{
runDown();
runKnightRider();
for (byte i=0; i<10; i++) { // loop 10 times for random LED
runRandom();
}
}

///////////////////////// turn on all LED
void allChannelOn(void) {
for (byte i=0; i<MAX_CHANNEL; i++) {
digitalWrite(Channel[i], HIGH);
}
}

///////////////////////// turn off all LED
void allChannelOff(void) {
for (byte i=0; i<MAX_CHANNEL; i++) {
digitalWrite(Channel[i], LOW);
}
}

///////////////////////// run LED in sequence
void runDown(void) {
for (byte i=0; i<MAX_CHANNEL; i++) {
allChannelOff();
digitalWrite(Channel[i], HIGH);
delay(interval);
}
}

void runKnightRider (void) {
allChannelOff();
for (byte i=0; i<MAX_CHANNEL; i++) {
digitalWrite(Channel[i], HIGH);
delay(interval);
}
for (byte i=0; i<MAX_CHANNEL; i++) {
digitalWrite(Channel[i], LOW);
delay(interval);
}
}

///////////////////////// run LED randomly
void runRandom(void) {
int allChannelState, previousState, state;
allChannelState= 0;

for (byte i=0; i<MAX_CHANNEL; i++) {
state= random(2);
allChannelState= allChannelState + state;
digitalWrite(Channel[i], state);
}

if (allChannelState==0) { //if all LED turned off
// reserved
} else {
delay(interval);
}
}

Arduino Tiny支援以下指令