Building a DIY Arduino Clone (1): Introduction

Table of contents

1. Building a DIY Arduino Clone (1): Introduction
2. Building a DIY Arduino Clone (2): Choosing Parts
3. Building a DIY Arduino Clone (3): Burning the Bootloader
4. Building a DIY Arduino Clone (4): Assembly to Completion

This series covers how to build your own Arduino-compatible board from scratch.
Not "build things with Arduino" — build the Arduino itself.

If you're just prototyping and will disassemble the circuit afterwards, a standard Arduino UNO is fine.
But if you want to leave circuits assembled for the long term, rolling your own is significantly cheaper.
Each board costs a few hundred yen, and you can omit unnecessary components to make it much smaller.

"Arduino-compatible" typically means one of the following:

• Software compatibility — works with the Arduino IDE


• Hardware compatibility — pin layout matches the Arduino UNO so existing shields can be used

This build targets software compatibility only.

Hardware compatibility is just about pin layout, so with careful wiring and soldering it should be achievable too. (Probably.)

The large chip sitting in the middle of an Arduino UNO is the ATmega328P microcontroller — that's what we're building around.

The ATmega328P has a built-in 8 MHz oscillator, and running on that internal clock reduces the part count.

You can also run it on an external 16 MHz crystal for higher speed.
If you need accurate timing, an external clock is necessary.

For example, IR remote controls use a 38 kHz carrier frequency.
Sending IR signals works fine with the internal clock, but receiving can be error-prone —
for reliable one-shot reception, an external clock is recommended.
(Multiple attempts averaged together can work with the internal clock though.)

That's enough preamble — more in the next part, where we'll choose the components.