Project Hub /IoT & Connected Devices/Environmental & Weather Monitoring/Programming ATtiny85 Microcontroller IC with Arduino Uno

Beginner

ARDUINO

₹500 – ₹1,500

3 – 6 Hours

Partial Kit

Programming ATtiny85 Microcontroller IC with Arduino Uno

Learn how to use an Arduino Uno as an ISP programmer to upload code to an ATtiny85 microcontroller using the Arduino IDE.

Originally published on CircuitDigest

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

Arduino UNO R3 Board (Compatible) – ATmega328P Microcontroller with USB Cable Rs. 999.00
10pcs 5mm RED Diffused Light Emitting Diodes - LEDs Set Rs. 39.00
10pcs - 220 ohm 1/4 W Resistor Set Rs. 39.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

This list includes a generic resistor set as a placeholder — it is not matched to the exact value or part number this circuit needs. The correct one is specified on the original source page linked above; check it before buying.

We don't carry yet: ATtiny

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How It Works

This project transforms an Arduino Uno into an In-System Programming (ISP) device, allowing it to act as a bridge between your computer and an ATtiny85 microcontroller. The Arduino Uno connects to your computer via USB to receive compiled firmware from the Arduino IDE. By running the ArduinoISP sketch on the Uno, the board uses its digital pins to supply power, clock signals, and data communication directly to the pins of the standalone ATtiny85 sitting on the breadboard. Jumper wires route the necessary SPI communication lines (MOSI, MISO, SCK) and the reset pin from the Uno to the target IC. Once the Uno is configured as a programmer, you can write code in the Arduino IDE and upload it directly to the ATtiny85 flash memory. To verify that the upload was successful and that your standalone microcontroller is functioning properly, you can connect an LED in series with a 220-ohm current-limiting resistor to one of the ATtiny85's programmable output pins. When the sketch runs, it drives the pin high, completing the circuit and illuminating the LED.

Why Build This

Transition permanent IoT and environmental monitoring projects from a bulky Arduino Uno to a tiny, power-efficient ATtiny85 IC.

Learn how to program bare microcontrollers using an existing development board as an ISP programmer without buying expensive standalone hardware.

Build ultra-compact DIY gadgets that consume minimal battery power for wearable or remote deployments.

Real-World Application

Shrinking down DIY electronics and IoT projects to compact, low-power form factors without needing a dedicated hardware programmer.

Skills You'll Learn

ISP programming

microcontroller bootstrapping

breadboard circuit prototyping

digital output control

firmware uploading

Safety Precautions

No specific precautions noted for this build — always follow general electronics safety practices.

Technology Tags

AVR

MICROCONTROLLER

ISP

ARDUINO IDE

EMBEDDED C

HARDWARE PROGRAMMING

Frequently Asked Questions

Can I leave the ATtiny85 permanently connected to the Arduino Uno after programming?

You can leave them wired together if you are testing, but the goal of this project is usually to remove the ATtiny85 and use it in a standalone circuit powered by its own battery.

Why do I need a 220-ohm resistor with the LED?

The resistor limits the amount of electrical current flowing through the LED, preventing it from burning out due to excessive current from the microcontroller pin.

Do I need to install any special software besides the Arduino IDE?

Yes, you will need to add the ATtiny board definitions to your Arduino IDE board manager so the software knows how to compile code specifically for the ATtiny85 architecture.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

Kitkraft Project Hub — curated from the maker community, credited at the source.

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