Sample project to measure time for a migration to a mobile solution with smaller arduino compatible board

Arduino_Sketch_to_Adafruit_Trinket.md

Any Arduino Sketch - How to upload to Adafruit Pro Trinket

Implementation - some (police) blue lights effect

• arduino uno test for .ino file and 2 leds https://github.com/jforge/arduino_blaulicht
• repeat with nano
• miniaturize with adafruit trinket:
  • connect with arduino IDE https://learn.adafruit.com/introducing-trinket/setting-up-with-arduino-ide
  • solder pins and repeat test with blaulicht.ino
  • solder lipo connector (Adafruiti Trinket LiIon/LiPoly Backpack) https://www.adafruit.com/product/2124
• test with trinket and LiPoly akku
• final hull/structure with shrink-on tube

Application

• mount on a cake, stick on wall, hat, bike...

Advanced

• wifi support, mqtt subscription for on/off, frequency

Hardware used here

Adafruit Pro Trinket 3V / 12 Mhz

USB-connection needs a programmer for the bootloader to upload an Arduino sketch.
Be aware, that there won't be any serial console using USB.

If this is not working for some reason, use a FTDI cable instead (which provides full serial/debug support)
with the respective FTDI pins on the Trinket.

For USB the following worked with Arduino 2.0.0-beta.11 (Host OS: MacOS BigSur 11.6):

(1) Prepare IDE:
After adding the

• Additional Board Manager URL (https://adafruit.github.io/arduino-board-index/package_adafruit_index.json) in Preferences.
• Adafruit AVR Boards in Tools → Boards Manager.

Select this particular microcontroller as a Board from the Boards list.
Then select the Tools → Programmer → USBtinyISP.

(2) Prepare hardware:
Plug in the Trinket, make sure you see the green LED lit (power good) and the red LED pulsing.
Press the reset button (if the red LED is not pulsing) to get into bootloader mode.

(3) Upload sketch:
Do NOT click the Upload button, BUT select from the Menu Sketch → Upload Using Programmer.