ATtiny 412

An ATtiny412 is a microcontroller that could be programmed by an Arduino. It uses very low power, but could produce a sizeable output. Even though it has much less functionality than an Arduino, it is enough for most electronics projects and applications.

Before Fab Academy started, I programmed an ATtiny412. A crucial thing to note is that the pins on the chip are confusing to read, but I will try my best to explain them down below.

Pin outs

When an Arduino programs an ATtiny412, the Arduino itself is a programmer.

Pin Description:

The first thing to note is there is a difference between the software and hardware pins.

On the Arduino Uno, the software pin is connected to pin 4 on the ATtiny 412, thi is not to be confused with the hardware pin on the Arduino. So, to program it in the Arduino software, you must put pin 2.

UPDI:

The UPDI supports ATtiny412 programming. It allows the Arduino to directly program the chip.

The UPDI pin is connected to pin 6 on the chip, but even though the software pin on the Arduino is 5, you have to connect it to pin 6 in order for it to work.

Blinking LED

Basic Workflow

Here is the basic workflow for creating a simple blinking LED (aka Hello World) program using the ATtiny 412.

1. Open 2018 version Arduino INC.
2. Go to file, examples, jtag2updi, make sure that the selected board is Arduino Uno R3.
3. Open jtag2updi code, and upload to Arduino Uno, this makes the arduino a programmer.
4. Go to file, examples, basic, blink.Open blink code.
5. Select board as ATtiny412 through tools, board, megaTinyCore.
6. Select programmer as jtag2updi.
7. Select chip as Attiny412, and Port as COM17.
8. Make sure to connect pin6 on the Arduino to UPDI pin on the ATtiny412.

Code for Blinking LED

/*
    Blink

Turns an LED on for one second, then off for one second, repeatedly.

 Most Arduinos have an on-board LED you can control. On the UNO, MEGA and ZERO are attached to digital pin 13, on MKR1000 on pin 6. 
 LED_BUILTIN is set to the correct LED pin independent of which board is used.

 By Scott Fizgerald, 8 May 2014.
 modified 2 Sep 2016 by Arturo Guadalupi
 modified 8 Sep 2016 by Colby Newman

 */

 // the setup function runs once when you press reset or power the board

 void setup(){
    // initialize digital pin LED_BUILTIN as an output.
    pinMode(2, OUTPUT);
 }

 // the loop function runs over and over again forever

 void loop(){
    digitalWrite(2, HIGH);
    delay (1000);
    digitalWrite(2, LOW);
    delay (1000);
 }

Wiring

This is the wiring for the program:

More information

To read more about milling out boards, click here.

To read more about setting up an ATtiny412 board, click here, the website is made by Teddy Warner.

---

Last update: May 14, 2023