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Editor: 洪正聰(中華科技大學電子系)
Arduino 介紹
一、誰
據說 Massimo Banzi 之前是義大利 Ivrea 一家高科技設計學校的老師。他的學生們經常抱怨找
不到便宜好用的微控制器。
2005 年冬天, Massimo Banzi 跟 David Cuartielles 討論了這個問題。David Cuartielles 是一
個西班牙籍晶片工程師,當時在這所學校做訪問學者。兩人決定設計自己的電路板,並引入了
Banzi 的學生 David Mellis 為電路板設計編程語言。兩天以後,David Mellis 就寫出了程式碼。
又過了三天,電路板就完工了。這塊電路板被命名為 Arduino。
發源地是義大利的 Ivrea 鎮,所以發起人以此鎮的歷史人物 Arduin 命名。"Arduino"是個義大利
的男子名,意思是"strong friend"。
http://zh.forvo.com/word/arduino/
幾乎任何人,即使不懂電腦編程,也能用 Arduino 做出很酷的東西,比如對感測器作出回應,
閃爍燈光,還能控制馬達。隨後 Banzi,Cuartielles,和 Mellis 把設計圖放到了網上。保持設計
的開放源碼理念,因為版權法可以監管開源軟體,卻很難用在硬體上,他們決定採用共享創意許
可。共享創意是為保護開放版權行為而出現的類似 GPL 的一種許可(license)。在共享創意許
可下,任何人都被允許生產電路板的複製品,還能重新設計,甚至銷售原設計的複製品。你不需
要付版稅,甚至不用取得 Arduino 團隊的許可。
然而,如果你重新發佈了引用設計,你必須說明原始 Arduino 團隊的貢獻。如果你調整或改動
了電路板,你的最新設計必須使用相同或類似的共享創意許可,以保證新版本的 Arduino 電路板
也會一樣的自由和開放。唯一被保留的只有 Arduino 這個名字。它被註冊成了商標。如果有人想
用這個名字賣電路板,那他們可能必須付一點商標費用給 Arduino 的核心開發團隊成員。
二、版本
三、模組
Arduino shield
四、感測器
五、支援作業系統
Windows
Mac OS X
Linux: 32 bit, 64 bit
六、UNO
http://arduino.cc/en/Main/ArduinoBoardUno
Arduino Uno R3 Front:
Arduino Uno R3 Back:
ATmega328 : datasheet http://www.atmel.com/Images/doc8161.pdf
硬體規格:
微控制器 ATmega328
工作電壓 5V
輸入電壓(建議) 7-12V
輸入電壓(限制) 6-20V
數位 I/O Pins 14 支(其中有 6 支腳位可提供 PWM 輸出)
類入 Input Pins 6 支
I/O pin 直流電流 40mA
3.3V pin 直流電流 50mA
Flash 記憶體 32KB, 其中 0.5KB 拿去給 bootloader 使用
SRAM 2KB
EEPROM 1KB
時脈 16MHz
數位 I/O Pins:
14 支數位 I/O Pins 可以當作 input 使用,也可以當作 output 使用,使用方法是透過 pinMode(),
digitalWrite(), and digitalRead() 這幾個函式。這 14 支數位 I/O Pins,其中幾支腳有特殊的功能:
Serial 通訊 0(RX) 和 1 (TX) 這兩支腳。用來接收(RX)與傳輸(TX) TTL 訊號的序列資
料。這兩支腳也連接到 USB Converter 晶片中。
外部中斷 2 和 3 這兩支腳。這兩支腳可以利用外部事件觸發中斷。詳細內容請參考
attachInterrupt() 函式。
PWM 3, 5, 6, 9, 10 和 11 共六支腳。透過 analogWrite() 函式可以提供 8-bit
的 PWM 輸出。
SPI 10 (SS), 11 (MOSI), 12 (MISO) 和 13 (SCK) 這四支腳。這四支腳搭配 SPI
Library 可提供 SPI 序列通訊。
LED 13。內建一顆 LED,當 pin 腳為 HIGH 時,LED 打開,當 pin 腳為 LOW 時,
LED 關閉。
類比輸入 Pins:
Arduino Uno 有 6 支類比輸入腳,標記為 A0 到 A5,每支腳都可提供 10 位元的解析 (即 1024 種不同
的數值)。這些腳位所用的參考電壓預設為 0 到 5V,不過參考電壓也是可以更改的,方法是透過 AREF 腳
和 analogReference() 函式。
另外,有幾支腳也有特殊功能:
I2C 4 (SDA) 和 5 (SCL) 這兩支腳。透過 Wire library 可以提供 I2C 通訊。
其它:
AREF 類比輸入的參考電壓,搭配 analogReference() 函式一起使用。
Reset 當 Reset 腳為 LOW 時,微控制器會重置。
Power
The Arduino Uno can be powered via the USB connection or with an external power supply. The
power source is selected automatically.
External (non-USB) power can come either from an AC-to-DC adapter (wall-wart) or battery. The
adapter can be connected by plugging a 2.1mm center-positive plug into the board's power jack.
Leads from a battery can be inserted in the Gnd and Vin pin headers of the POWER connector.
The board can operate on an external supply of 6 to 20 volts. If supplied with less than 7V, however,
the 5V pin may supply less than five volts and the board may be unstable. If using more than 12V,
the voltage regulator may overheat and damage the board. The recommended range is 7 to 12 volts.
The power pins are as follows:
VIN. The input voltage to the Arduino board when it's using an external power source (as opposed
to 5 volts from the USB connection or other regulated power source). You can supply voltage
through this pin, or, if supplying voltage via the power jack, access it through this pin.
5V.This pin outputs a regulated 5V from the regulator on the board. The board can be supplied
with power either from the DC power jack (7 - 12V), the USB connector (5V), or the VIN pin of the
board (7-12V). Supplying voltage via the 5V or 3.3V pins bypasses the regulator, and can damage
your board. We don't advise it.
3V3. A 3.3 volt supply generated by the on-board regulator. Maximum current draw is 50 mA.
GND. Ground pins.
Memory
The ATmega328 has 32 KB (with 0.5 KB used for the bootloader). It also has 2 KB of SRAM and 1
KB of EEPROM (which can be read and written with the EEPROM library).
Input and Output
Each of the 14 digital pins on the Uno can be used as an input or output,
using pinMode(), digitalWrite(), and digitalRead()functions. They operate at 5 volts. Each pin can
provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by
default) of 20-50 kOhms. In addition, some pins have specialized functions:
Serial: 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data. These pins
are connected to the corresponding pins of the ATmega8U2 USB-to-TTL Serial chip.
External Interrupts: 2 and 3. These pins can be configured to trigger an interrupt on a low
value, a rising or falling edge, or a change in value. See the attachInterrupt() function for details.
PWM: 3, 5, 6, 9, 10, and 11. Provide 8-bit PWM output with the analogWrite() function.
SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI communication using
the SPI library.
LED: 13. There is a built-in LED connected to digital pin 13. When the pin is HIGH value, the LED
is on, when the pin is LOW, it's off.
The Uno has 6 analog inputs, labeled A0 through A5, each of which provide 10 bits of resolution
(i.e. 1024 different values). By default they measure from ground to 5 volts, though is it possible to
change the upper end of their range using the AREF pin and the analogReference() function.
Additionally, some pins have specialized functionality:
TWI: A4 or SDA pin and A5 or SCL pin. Support TWI communication using the Wire library.
There are a couple of other pins on the board:
AREF. Reference voltage for the analog inputs. Used with analogReference().
Reset. Bring this line LOW to reset the microcontroller. Typically used to add a reset button to
shields which block the one on the board.
See also the mapping between Arduino pins and ATmega328 ports. The mapping for the Atmega8,
168, and 328 is identical.
Communicat ion
The Arduino Uno has a number of facilities for communicating with a computer, another Arduino,
or other microcontrollers. The ATmega328 provides UART TTL (5V) serial communication, which
is available on digital pins 0 (RX) and 1 (TX). An ATmega16U2 on the board channels this serial
communication over USB and appears as a virtual com port to software on the computer. The
'16U2 firmware uses the standard USB COM drivers, and no external driver is needed.
However, on Windows, a .inf file is required. The Arduino software includes a serial monitor which
allows simple textual data to be sent to and from the Arduino board. The RX and TX LEDs on the
board will flash when data is being transmitted via the USB-to-serial chip and USB connection to
the computer (but not for serial communication on pins 0 and 1).
A SoftwareSerial library allows for serial communication on any of the Uno's digital pins.
The ATmega328 also supports I2C (TWI) and SPI communication. The Arduino software includes
a Wire library to simplify use of the I2C bus; see the documentation for details. For SPI
communication, use the SPI library.
Programming
The Arduino Uno can be programmed with the Arduino software (download). Select "Arduino Uno
from the Tools > Board menu (according to the microcontroller on your board). For details, see
the reference and tutorials.
The ATmega328 on the Arduino Uno comes preburned with a bootloader that allows you to upload
new code to it without the use of an external hardware programmer. It communicates using the
original STK500 protocol (reference, C header files).
You can also bypass the bootloader and program the microcontroller through the ICSP (In-Circuit
Serial Programming) header; see these instructions for details.
The ATmega16U2 (or 8U2 in the rev1 and rev2 boards) firmware source code is available .
The ATmega16U2/8U2 is loaded with a DFU bootloader, which can be activated by:
On Rev1 boards: connecting the solder jumper on the back of the board (near the map of Italy) and
then resetting the 8U2.
On Rev2 or later boards: there is a resistor that pulling the 8U2/16U2 HWB line to ground, making
it easier to put into DFU mode.
You can then use Atmel's FLIP software (Windows) or the DFU programmer (Mac OS X and Linux)
to load a new firmware. Or you can use the ISP header with an external programmer (overwriting
the DFU bootloader). See this user-contributed tutorial for more information.
Automat ic (Sof tware) Reset
Rather than requiring a physical press of the reset button before an upload, the Arduino Uno is
designed in a way that allows it to be reset by software running on a connected computer. One of
the hardware flow control lines (DTR) of theATmega8U2/16U2 is connected to the reset line of
the ATmega328 via a 100 nanofarad capacitor. When this line is asserted (taken low), the reset line
drops long enough to reset the chip. The Arduino software uses this capability to allow you to
upload code by simply pressing the upload button in the Arduino environment. This means that
the bootloader can have a shorter timeout, as the lowering of DTR can be well-coordinated with the
start of the upload.
This setup has other implications. When the Uno is connected to either a computer running Mac
OS X or Linux, it resets each time a connection is made to it from software (via USB). For the
following half-second or so, the bootloader is running on the Uno. While it is programmed to
ignore malformed data (i.e. anything besides an upload of new code), it will intercept the first few
bytes of data sent to the board after a connection is opened. If a sketch running on the board
receives one-time configuration or other data when it first starts, make sure that the software with
which it communicates waits a second after opening the connection and before sending this data.
The Uno contains a trace that can be cut to disable the auto-reset. The pads on either side of the
trace can be soldered together to re-enable it. It's labeled "RESET-EN". You may also be able to
disable the auto-reset by connecting a 110 ohm resistor from 5V to the reset line; see this forum
thread for details.
USB Overcurrent Protect ion
The Arduino Uno has a resettable polyfuse that protects your computer's USB ports from shorts
and overcurrent. Although most computers provide their own internal protection, the fuse
provides an extra layer of protection. If more than 500 mA is applied to the USB port, the fuse will
automatically break the connection until the short or overload is removed.
Phys ica l Character is t ics
The maximum length and width of the Uno PCB are 2.7 and 2.1 inches respectively, with the USB
connector and power jack extending beyond the former dimension. Four screw holes allow the
board to be attached to a surface or case. Note that the distance between digital pins 7 and 8 is 160
mil (0.16"), not an even multiple of the 100 mil spacing of the other pins.
1. open-source Arduino environment:
http://arduino.cc/en/Main/Software
Download Arduino 1.0.5 (release notes), hosted by Google Code:
Windows
Mac OS X
Linux: 32 bit, 64 bit
Wiring-based language (syntax and libraries), similar to C++ with some slight simplifications and
modifications, and a Processing-based integrated development environment.[
http://en.wikipedia.org/wiki/Arduino http://arduino.cc/en/Reference/HomePage
一 、 Standard Libraries
EEPROM - reading and writing to "permanent" storage
Ethernet - for connecting to the internet using the Arduino Ethernet Shield
Firmata - for communicating with applications on the computer using a standard
serial protocol.
LiquidCrystal - for controlling liquid crystal displays (LCDs)
SD - for reading and writing SD cards
Servo - for controlling servo motors
SPI - for communicating with devices using the Serial Peripheral Interface (SPI) Bus
SoftwareSerial - for serial communication on any digital pins
Stepper - for controlling stepper motors
Wire - Two Wire Interface (TWI/I2C) for sending and receiving data over a net of
devices or sensors.
二 、 Leonardo Only Libraries
Keyboard - Send keystrokes to an attached computer.
Mouse - Control cursor movement on a connected computer.
三 、 Contributed Libraries
Code
The example code is very simple, credits are to be found in the comments.
/* Blinking LED
* ‐‐‐‐‐‐‐‐‐‐‐‐
*
* turns on and off a light emitting diode(LED) connected to a digital
* pin, in intervals of 2 seconds. Ideally we use pin 13 on the Arduino
* board because it has a resistor attached to it, needing only an LED
*
* Created 1 June 2005
* copyleft 2005 DojoDave <http://www.0j0.org>
* http://arduino.berlios.de
*
* based on an orginal by H. Barragan for the Wiring i/o board
*/
int ledPin = 13; // LED connected to digital pin 13
void setup()
{
pinMode(ledPin, OUTPUT); // sets the digital pin as output
}
void loop()
{
digitalWrite(ledPin, HIGH); // sets the LED on
delay(1000); // waits for a second
digitalWrite(ledPin, LOW); // sets the LED off
delay(1000); // waits for a second
}
七、參考資料
參考資料:
八、參考實作
Button: http://www.seeedstudio.com/wiki/GROVE_-_Starter_Kit_V0.9b
http://www.arduino.cc/en/Tutorial/button
LED: http://www.seeedstudio.com/wiki/GROVE_-_Starter_Kit_V0.9b
程式
http://www.arduino.cc/en/Tutorial/BlinkingLED
Tilt switch:
http://www.seeedstudio.com/wiki/GROVE_-_Starter_Kit_V0.9b
http://www.arduino.cc/en/Tutorial/TiltSensor
Light Sensor:
http://www.seeedstudio.com/wiki/Grove_-_Light_Sensor
Rotary angle sensor
http://www.seeedstudio.com/wiki/GROVE_-_Starter_Kit_v1.1b#Grove_-_Rot
ary_Angle_Sensor
Sound Sensor: http://www.seeedstudio.com/wiki/Grove_-_Sound_Sensor
int ledPin = 13;
int time = 1000;
void setup() {
pinMode(ledPin, OUTPUT);
Serial.begin(9600);
Serial.println("\n[memCheck]");
Serial.println(freeRAM(), DEC);
}
void loop() {
digitalWrite(ledPin, HIGH);
delay(time);
digitalWrite(ledPin, LOW);
delay(time);
}
int freeRAM() {
extern int __heap_start, *__brkval;
int v;
return (int) &v - (__brkval == 0 ? (int) &__heap_start : (int)
__brkval);
}
int k=0;
void setup()
{
Serial.begin(9600);
}
void loop()
{
char c;
if(Serial.available()>0)
{
c=Serial.read();
Serial.print(c);
k=1;
}
else
{ if (k!=0)
{
Serial.println();
k=0;
}
}
delay(100);
}