Making it Miniature: Integrating the ATtiny85

The ATtiny85 dip is a powerhouse of an IC. It has almost all the functionality an Arduino Uno has, only offering fewer I/O pins. For projects where six or less I/O pins are needed, the ATtiny85 is the best choice from the Atmel family of microchips.

Step One: Pinout

The ATtiny85 has six I/O pins, marked PB0 - PB5, and VCC and GND connections. All of the I/O pins feature digitalWrite() and digitalRead() capabilities, and four of the I/O pins have analogRead() capabilities, marked A0 - A3. Finally, the chip has PWM on two pins, PB0 and PB1. It also lacks a built-in UART, meaning it cannot perform serial communication via hardware. However, there are work arounds such as the SoftwareSerial library, turning serial communication from hardware to software: they are virtually the same.

Step Two: Programming

To start with hardware connections as it's easier than the software section of the ATtiny85 programming, make the connections you see above. Note that an Arduino Uno is needed to program the chip or an external USB programmer module (the Arduino method is much better). After making the connections, open the example sketches in the Arduino IDE and open the sketch "ArduinoISP."

You need to delete the "//" in line 81. After the deletion, upload this code to the Arduino Uno. Now, open the Arduino settings and go to "Additional Boards Manager URLs" and paste these two links: (one on separate lines; order doesn't matter) 1: "http://drazzy.com/package_drazzy.com_index.json" 2: "https://raw.githubusercontent.com/damellis/attiny/ide-1.6.x-boards-manager/package_damellis_attiny_index.json". Now, select the proper comm port; under tools, select the proper board, ATtiny85, and processor, ATtiny85, and under the programmer, still under tools, select Arduino as ISP. Then write your code (To start, I would recommend blinking an LED as seen in the image above). When your code is ready, make sure everything is set under the tools bar correctly as mentioned previously. Now select the sketch tab, and click "Upload using programmer."

Step Three: Power

The ATtiny85's operating voltage range is between 2.7-5.5V. So it's fine to power it using 5V from Arduino, but coin cell batteries are also very useful.

Step Four: Making

I've made a few projects so far with the ATtiny85, and it does not disappoint. If you would like to see other projects I've made with the ATtiny85 like this stealthy human movement detection device, check out my personal website here.