The most useful thing to have when working with embedded electronics is to have in-circuit programmers. Please don't get into the habit of swapping parts betwee

The most useful thing to have when working with embedded electronics is to have in-circuit programmers. Please don't get into the habit of swapping parts between, e.g., the Arduino board and your own... It's getting very tedious, very fast. The simplest programmers (ISP: In System Programmer) are only a few dollars, and they allow you to burn your creations in blank off-the-factory chips without bootloader. I think there's even an Arduino project that turns your arduino into a (very limited) STK500 compatible programmer... [a quick web search turns up https://www.arduino.cc/en/Tutorial/ArduinoISP https://www.arduino.cc/en/Tutorial/ArduinoISP ]