Introduction: Attiny85 Mini-Arduino

This is an Arduino like board that uses an Attiny85 microcontroller. It can be programmed using the Arduino IDE.

You will need:

Adafruit Perma-Proto Quarter-sized Breadboard PCB

2.1mm barrel jack

2 10mf electrolytic capacitors

7805 Voltage regulator

330-560 Ohm 1/4 Watt resistor. (purchased locally)

Red 5mm LED (purchased locally)

22 gauge hookup wire (I used Red, Black, and Green, purchased locally)

9 Volt battery clip

9 Volt battery. (purchased locally)

Attiny85 micro controller

8 pin IC socket

2 IDC breadboard helper

6mm Pushbutton Switch

Tiny AVR Programmer

6-pin Socket/Socket IDC cable

Male Headers

Female Headers

Step 1: The Power Supply

Solder the barrel jack into holes A-1 and A-3 on the board. Solder the lead on the side into Ground Rail-2.

Solder a black wire from E-1 to F-2.

Solder a red wire from E-3 to F-3.

Solder one of the 10mf capacitors in holes D-1 and D-3. The short lead goes in D-1.

Solder a red wire from J-1 to Positive Rail-1.
Solder a black wire from J-2 to Ground Rail-2.

Solder the other 10mf capacitor between I-1 and I-2. The short lead goes in I-2.

Solder the 7805 regulator into holes G-1, G-2, and G-3. The side with the most metal showing points to the Barrel jack.

Solder a red wire from Positive Rail-4 to Positive Rail-4 on the other side.

Solder a black wire from Ground Rail-3 to Ground Rail-3 on the other side.

Solder the 330-560 Ohm resistor between D-5 and F-5, polarity doesn't matter.

Solder the short lead on the red LED into hole J-5 and the long lead into the fifth hole on the positive rail.

Solder a black wire from hole A-5 to the fifth hole in the ground rail on the side with the barrel jack.

This completes the power supply. To test it plug in the battery. The LED should light and the voltage regulator should not get hot.


Edited 4/17/16 - Added Fritzing diagram. The image on the right shows the position of the voltage regulator and the capacitor, If they were in the same picture it would get a little busy.

Step 2: Microcontroller Socket and ICSP Header

Solder the In Circuit Serial Programmer (ICSP) header into Holes E-6 through E-8 and F-6 Through F-8. Wrap a small rubber band around it to hold it in place while soldering the first pin.

Solder a red wire from J-6 to Positive Rail-6.

Solder a black wire from J-8 to Ground Rail-8.

Solder the IC socket into holes E-12 through E-15 and F-12 Through F-15. The alignment notch points away from the power supply. Hold it in place with the rubber band.

Solder a black wire from D-8 to G-15. (Reset)

Solder a black wire from J-12 to Ground Rail-12. (Ground)

Solder a red wire from A-15 to Positive Rail-15. (VCC)

Solder a green wire from G-7 to D-12. (MOSI)

Solder a green wire from C-7 to C-14. (SCK)

Solder a green wire from B-6 to B-13.(MISO)

Step 3: The Reset Button

Clip the leads off one side of the 6mm pushbutton switch.

Solder the remaining pins on the switch into J-9 and J-11.

Solder a black wire from H-9 to H-15.

Solder a black wire from I-8 to I-11.

Step 4: Headers

Cut two pieces of the male headers with two pins.

Solder the male headers from the top with the long side down. They go in Ground Rail-14 and 15, and Positive Rain-14 and 15. These pins are used to attach the board to a breadboard, and to activate the power rails on the breadboard.

Cut two pieces of the female headers. One piece with two pins and one with three. Leave enough extra so you can sand the cut edges smooth.

Solder the three pin header into A-12 through A-14.

Solder the two pin header into J-13 and J-14.

Attiny85 Pinouts:
            Reset    1   \/   8  VCC 5 Volts
   Analog In 3, PB3  2        7  PB2, Analog In 1, I2C SCL, SPI SCK
   Analog In 2, PB4  3        6  PB1, PWM, SPI MISO
             Ground  4        5  PB0, PWM, I2C SDA, SPI MOSI<br>

Edited 4/17/16 - Improved picture and added a fritzing diagram.

Step 5: Programmer

Plug the Attiny85 chip into the socket, make sure you have the small alignment dot on the chip at the same end as the notch in the socket.

Solder the 2x3 pin male header from the second IDC breadboard helper into the empty 2x3 space on the Tiny AVR Programmer. The pins point up on the same side as the socket.

If you look closely at the first photo you will notice a small vertical line just to the left of the top left pin. This is the pin number one marker on the Tiny AVR Programmer.

On the board Pin number one is closest to the power supply.

Connect the ICSP cable like in the second photo.

Follow this link for instructions on how to add the Attiny85 definitions to the Arduino IDE:

Step 6: Testing

Attiny85 Pinouts:
Reset 1 \/ 8 VCC 5 Volts Analog In 3, PB3 2 7 PB2, Analog In 1, I2C SCL, SPI SCK Analog In 2, PB4 3 6 PB1, PWM, SPI MISO Ground 4 5 PB0, PWM, I2C SDA, SPI MOSI

For this test you will need 5 LEDs, 5 resistors 330-560 Ohm 1/4 Watt, and some jumper wires.

Hook up 5 LEDs to pins PB0 - PB4 with a resistor on each LED.

Copy/paste the following code into the Adruino IDE and upload it to your new board:

int LED[] {0,1,2,3,4};
void setup() { for(int i=0;i<5;i++) pinMode(LED[i], OUTPUT); } void alloff() { for(int i=0;i<5;i++) digitalWrite(LED[i], LOW); } void loop() { for(int i=0;i<5;i++) { alloff(); digitalWrite(LED[i], HIGH); delay(500); } }

The five LEDs should blink in sequence.


JRV31 made it! (author)2016-04-17

Since writing this instructable my photography skills have improved and I learned about Fritzing. I edited it today to add better photos and a Fritzing diagram.

zonkerharris (author)JRV312017-01-16

Thank you for posting this instructable. I'm glad to see the corrected image (with the positive jumper between the two power rails). The text was correct, but the wrong image is still displayed on the page. As an author, I think you can remove the old image, and add the new one on step 1. (I just posted my first instructable, annd was happy to see how easy it is to do. )

seamster (author)2014-12-05

Cool, thanks for sharing this!

About This Instructable




Bio: Most of my instructables will be tutorials for Atmel microcontrollers, Arduino, or Raspberrypi. I try to show concepts that you can use in your own ... More »
More by JRV31:Non-slip SoxMoonLight7400 Quad Nand Gate Simulation
Add instructable to: