Arduino makefile无法编译

Question

我正在尝试用Makefile编译我的Arduino文件/项目。但我对全局变量有问题。上面说没有申报。我下载的makefile来自github：https://github.com/sudar/Arduino-Makefile。

因为我对阿迪诺没有经验，所以我看不出有什么问题。

我的错误代码：

    -------------------------
    Arduino.mk Configuration:
    - [AUTODETECTED] CURRENT_OS = LINUX
    - [COMPUTED] ARDMK_DIR = /usr/share/arduino (relative to Common.mk)
    - [USER] ARDUINO_DIR = /usr/share/arduino
    - [AUTODETECTED] ARDUINO_VERSION = 105
    - [DEFAULT] ARDUINO_SKETCHBOOK = /sketchbook
    - [BUNDLED] AVR_TOOLS_DIR = /usr/share/arduino/hardware/tools/avr (in Arduino distribution)
    - [COMPUTED] ARDUINO_LIB_PATH = /usr/share/arduino/libraries (from ARDUINO_DIR)
    - [DEFAULT] ARDUINO_CORE_PATH = /usr/share/arduino/hardware/arduino/cores/arduino
    - [COMPUTED] ARDUINO_VAR_PATH = /usr/share/arduino/hardware/arduino/variants (from ARDUINO_DIR)
    - [COMPUTED] BOARDS_TXT = /usr/share/arduino/hardware/arduino/boards.txt (from ARDUINO_DIR)
    - [DEFAULT] USER_LIB_PATH = /sketchbook/libraries (in user sketchbook)
    - [USER] BOARD_TAG = uno
    - [COMPUTED] OBJDIR = build-uno (from BOARD_TAG)
    - [ASSUMED] MONITOR_BAUDRATE = 9600
    - [DEFAULT] OPTIMIZATION_LEVEL = s
    - [DEFAULT] MCU_FLAG_NAME = mmcu
    - [DEFAULT] CFLAGS_STD = -std=gnu99
    - [AUTODETECTED] Size utility: AVR-aware for enhanced output
    -
    - ARDUINO_LIBS =
    - [SYSTEM] Wire
    - [SYSTEM] EEPROM
    - [SYSTEM] Esplora
    - [SYSTEM] Ethernet
    - [SYSTEM] Firmata
    - [SYSTEM] GSM
    - [SYSTEM] LiquidCrystal
    - [SYSTEM] Robot_Control
    - [SYSTEM] Robot_Motor
    - [SYSTEM] SD
    - [SYSTEM] Servo
    - [SYSTEM] SoftwareSerial
    - [SYSTEM] SPI
    - [SYSTEM] Stepper
    - [SYSTEM] TFT
    - [SYSTEM] WiFi
    - [SYSTEM] Wire
    - [SYSTEM] Wire/utility
    - [SYSTEM] Ethernet/utility
    - [SYSTEM] Robot_Control/utility
    - [SYSTEM] SD/utility
    - [SYSTEM] TFT/utility
    - [SYSTEM] WiFi/utility
    - [SYSTEM] Wire/utility
    - [COMPUTED] BOOTLOADER_PARENT = /usr/share/arduino/hardware/arduino/bootloaders (from ARDUINO_DIR)
    -------------------------
    /usr/share/arduino/hardware/tools/avr/bin/avr-g++ -MMD -c -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=105 -I. -I/usr/share/arduino/hardware/arduino/cores/arduino -I/usr/share/arduino/hardware/arduino/variants/standard -I/usr/share/arduino/libraries/Wire -I/usr/share/arduino/libraries/EEPROM -I/usr/share/arduino/libraries/Esplora -I/usr/share/arduino/libraries/Ethernet -I/usr/share/arduino/libraries/Firmata -I/usr/share/arduino/libraries/GSM -I/usr/share/arduino/libraries/LiquidCrystal -I/usr/share/arduino/libraries/Robot_Control -I/usr/share/arduino/libraries/Robot_Motor -I/usr/share/arduino/libraries/SD -I/usr/share/arduino/libraries/Servo -I/usr/share/arduino/libraries/SoftwareSerial -I/usr/share/arduino/libraries/SPI -I/usr/share/arduino/libraries/Stepper -I/usr/share/arduino/libraries/TFT -I/usr/share/arduino/libraries/WiFi -I/usr/share/arduino/libraries/Wire -I/usr/share/arduino/libraries/Wire/utility -I/usr/share/arduino/libraries/Ethernet/utility -I/usr/share/arduino/libraries/Robot_Control/utility -I/usr/share/arduino/libraries/SD/utility -I/usr/share/arduino/libraries/TFT/utility -I/usr/share/arduino/libraries/WiFi/utility -I/usr/share/arduino/libraries/Wire/utility -Wall -ffunction-sections -fdata-sections -Os -fno-exceptions main.cpp -o build-uno/main.o
    main.cpp: In function 'void setup()':
    main.cpp:17:16: error: 'OUTPUT' was not declared in this scope
    pinMode(led, OUTPUT);
    ^
    main.cpp:17:22: error: 'pinMode' was not declared in this scope
    pinMode(led, OUTPUT);
    ^
    main.cpp: In function 'void loop()':
    main.cpp:23:30: error: 'analogWrite' was not declared in this scope
    analogWrite(led, brightness);
    ^
    main.cpp:33:11: error: 'delay' was not declared in this scope
    delay(30);
    ^
    make: *** [build-uno/main.o] Error 1

Answer 1

Arduino IDE做了一些Arduino-Makefile不做的“草图预处理”(参见https://github.com/arduino/arduino-preprocessor#about-the-arduino-sketch-ino-preprocessing)。换句话说，Arduino IDE在尝试编译它之前修改您的sketch.ino以将其转换为C++，而Arduino-Makefile则尝试编译它而不做任何更改。

因此，Arduino-Makefile无法编译一些使用Arduino IDE编译得很好的草图。手工执行这些操作通常有三个步骤：

1. 有很多源文件吗？如果是，将它们合并到一个文件中。
2. #include <Arduino.h>是否位于单个源文件的顶部？如果没有，就加进去。
3. 所有函数在使用前都声明好了吗？如果没有，则添加前向声明。

在您的示例中，似乎需要步骤2(缺少的变量OUTPUT和编译错误消息中的缺失函数是在Arduino.h中声明的，参见https://github.com/arduino/Arduino/blob/master/hardware/arduino/avr/cores/arduino/Arduino.h)。

如果您打算继续使用Arduino-Makefile，我建议您习惯这些类型的错误，因为您将在网络上找到的大多数草图都只使用Arduino IDE进行测试。好的一面是，将它们转换为C++通常是微不足道的，而且很少花费时间，因为Arduino草图很少“大”。