Arduino

General

Startup & Programming

On reset or powerup, ehe Optiboot or other bootloader code is run. If an external reset was the cause, listening mode is entered, and the LED is flashed. Programming commands in STK500 protocol are listened for, of the serial line at 115200 speed. If none are received in a small timeout window (~ 1s), the normal code is executed.

The DTR line if used to trigger a reset pulse in software IDE (see here).

millis()

• Useful for timing without using a blocking delay()
• Returns ms in an unsigned long
• Test for 1s (subtraction correctly handles truncation/rollover):
  • millis() - lastCounter > 1000
• https://arduino.stackexchange.com/questions/12587/how-can-i-handle-the-millis-rollover/12588#12588

Documentation

• Arduino Language Reference

Useful Libraries

• Standard Libraries

• FastLED for WS2812B programmable LED strips
  • Code Examples
  • Colour Reference
• FreeRTOS
• LibPrintf
• LiquidCrystal_PCF8574 derived from Liquid Crystal
• OneButton
• Pin Change Interrupt
• TinyGPS

Hardware

• Arduino Duemilanove
  • ATmega328 (16 MHz)
  • PlatformIO
• Arduino Uno R3
  • ATmega328P (16 MHz)
  • PlatformIO
• SparkFun Pro Micro
  • ATMEGA32U4 (16 MHz)
  • PlatformIO
  • Direct USB -> can appear as mouse/keyboard
• Arduino Nano
  • ATmega328PB (Micro USB) (16 MHz)
    • PlatformIO
  • ATmega328PB (USBC) (16 MHz)
    • PlatformIO

See: 328PB additions.

Development Environment

• Visual Studio Code, install Platform.io IDE extension
  • See [https://docs.platformio.org/en/latest/integration/ide/vscode.html#quick-start Quck Start)
• Extension icon -> New Project
  • include - header files
  • lib - libraries
  • src - C++ source files
  • platformio.ini
  • See small icons at bottom for Home, Build, Upload, Serial Monitor

• SHIFT-ALT-F to format document

Platformio.ini

Common additions:

lib_deps = fastled/FastLED@^3.10.3
monitor_speed = 115200
upload_port = COM3