Techduino ||How to Make Your Own Homemade Arduino Uno R3||




About: I have some interest in electronic. you can find me at

If you're like me, after I got my Arduino and performed a final programming on my first chip, I wanted to pull it off my Arduino Uno R3 and put it on my own circuit. This would also free up my Arduino for future projects. After reading through many web pages and forums, I was able to put together this Instructable. I wanted to have the information I learned all in one place, and easy to follow.Comments and suggestions are welcome and appreciated as I'm still trying to learn all this stuff.

Step 1: Parts Needed

To do this, you'll need:

Basic Parts for wiring up Arduino

  1. A breadboard 22 AWG wire
  2. 7805 Voltage regulator
  3. 2 LEDs 2 220 Ohm resistors
  4. 1 10k Ohm resistor
  5. 2 10 uF capacitors
  6. 16 MHz clock crystal
  7. 2 22 pF capacitors
  8. small momentary normally open ("off") button

Step 2: Adding Circuitry for a Power Supply

Here I am using 5V mobile charger instead of LM7805 (This version uses a 5V regulated power supply). It's simple and save some space on board. You can you LM7805 but after that you have to use a higher voltage supply that's why I'm using 5V constant charger.

Step 3: ATMEGA8/168/328 Basics

Before moving on, check out this image. It's a great resource for learning what each of the pins on your Atmega chip do in relation to the Arduino's functions. This will clarify a lot of confusion behind why you hook up certain pins the way you do. For even more detailed information, take a peek at the datasheet for the Atmega168 (short version) (long version). Here's the sheet for the Atmega328 (short version) (long version)

Step 4: Start the Project

Start by connecting a 10k ohm pullup resistor to +5V from the RESET pin in order to prevent the chip from resetting itself during normal operation. The RESET pin reboots the chip when pulled down to ground.

Pin 7 - Vcc - Digital Supply Voltage

Pin 8 - GND

Pin 22 - GND

Pin 21 - AREF - Analog reference pin for ADC

Pin 20 - AVcc - Suppply voltage for the ADC converter. Needs to be connected to power if ADC isn't being used and to power via a low-pass filter if it is (a low pass filter is a circuit that reduces noise from the power source. This example isn't using one)

Step 5: Adding Cristal

Add a 16 MHz external clock between pin 9 and 10, and add two 22 pF capacitors running to ground from each of those pins.

Step 6: Adding Reset Switch

Add the small tactile switch so that you can reset the Arduino whenever we'd like and prepare the chip for uploading a new program. A quick momentary press of this switch will reset the chip when needed. Add the switch just above the top of the Atmega chip crossing the gap in the breadboard. Then, add a wire from the bottom left leg of the switch to the RESET pin of the Atmega chip and a wire from the top left leg of the switch to ground.

Step 7: LED Leads on Arduino Pin 13

The chip used on this board is actually already programmed using the blink_led program that comes with the Arduino software. If you already have an Arduino printed circuit board running, it is a good idea to go ahead and check the breadboard version you are building with a chip you know works. Pull the chip from your working Arduino and try it on this board. The blink_led program blinks pin 13. Pin 13 on the Arduino is NOT the AVR ATMEGA8-16PU/ATMEGA168-16PU pin 13. It is actually pin 19 on the Atmega chip.

Finally, add the LED. The long leg or the anode connects to the red wire and the short leg or the cathode connects to the 220 ohm resistor going to ground.

Step 8: Arduino-Ready!

At this point if you had already programmed your chip somewhere else and didn't need this breadboard circuit to reprogram the chip, you could stop here. But part of the fun is in-circuit programming so keep going to really make a full USB-Arduino-circuit on a breadboard!

Step 9: Software to Be Used

To make this Techduino Board I used Circuit Wizard Trial Version Software. You can use It or I'm providing the required circuit diagram and PCB layout here.

Thanks For viewing my project.



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    14 Discussions


    2 years ago

    wow. its impotent. thanx


    2 years ago

    This amazing Thank you this great action


    2 years ago

    AREF should not be tied to +5V unless you feel like blowing up your ATMega when you do analogRead() without calling analogReference(EXTERNAL) first.

    Good practice would be to pull it down to ground via a 100k resistor.

    2 replies
    Tech WorksDavidV12

    Reply 2 years ago

    I'm using this board from a while and I think its working like a arduino. It is the best way to use arduino for long duration purpose. I'm using it in a project which is continuously working for 24*7 and I have no problem like anything. And according to arduino site it is the best way to connect it with 5V

    DavidV12Tech Works

    Reply 2 years ago

    Look at the schematics for both the duemilanove and the uno: neither one connects AREF to +5V. Also take a note of the warning on the analogReference page in the Arduino API documentation.

    The original version of the Arduino on a breadboard page had the connection in error (the current version does not) and for years people have been propagating it cargo-cult style.

    AREF is best left floating or pulled down to ground for safety.

    Also see pages 305 and 311 of the ATMega328 datasheet.


    2 years ago

    Prof. R. Jayaram.

    Very useful for beginners.

    Tech WorksTyler_Reyes

    Reply 2 years ago

    You just have to buy a FTDI FT232RL FT232 USB And Connect it with your home made home made arduino


    2 years ago

    Very nice. Looks like I'm going to be building myself a ton of microcontrollers.

    1 reply

    This is a great project. Building something from scratch is the best way to learn how it works.

    1 reply