Introduction: DIY Arduino Uno

About: I love the whole world of science. I'm doing all these since i was a kid..! ;)

Hi guys! This instructables is for all who wish to make an arduino uno on their own. This is useful for those who are the beginners in arduino and also who want to make it particularly for a project. Some projects may require permanent fixing of arduino, and of course it'll be just too costly to buy a new arduino for every new project. The main component here which is the heart and brain of the whole circuit is the Atmel's ATmega328 chip. Its all about this chip which allows you to do all the open source programming and then control the hardwares and sensors. So, get ready with your soldering iron and all mini tools.. ;)

Step 1: Components Required

1. ATmega328P-PU (make sure that the chip has the last alphabet i.e, 'P'. It means it already has bootloader.)
2. USB to UART serial converter (It has 6 data communicating pins on the other side.)
3. 7805 Voltage regulator IC.
4. Some sets of 40*1 pcs of male and female pin headers.
5. DC Power Supply Socket(Also known as 'Barrel Jack') Optional, if you're not new to electronics.
6. 16MHz. Crystal Oscillator.
7. 2 pcs of 22pF ceramic capacitors.
8. 2 pcs of 100nF ceramic capacitors.
9. 10k 1/4watt resistor.
10. 2 pcs of 470ohms 1/4watt resistors.
11. 1 red LED and 1 yellow LED(Red one for power indicator and yellow for troubleshooting.)
12. 2 pcs of 10uF electrolytic capacitors.
13. 28 pin IC socket/base.
14. A small dotted PCB.
15. Single strand wires for jumping terminals and points.

Step 2: Initializing the Components on PCB

Before starting any fixing and soldering work, i would advise u to decide several times about where and how you're going to place all the components and output female headers. Make efficient use of the PCB space and try to be neat at your work, which not only looks good but also makes easy to spot any mistake done by chance. Use a black marker to mark the places where you're going to put the components. According to circuit diagram, plan your project.!

Step 3: Putting All the Components

Watch the circuit nicely and solder the components on the board. By the way, this schematic is not my own, i've just edited this and corrected its errors. Try to minimize the use of jumpers. There's nothing much difficult in this step. Firstly, put the respective LEDs, crystal, then the voltage regulator and filter capacitors. You can use the capacitors more than the given value for better filtration such as 47uF, etc.. One more thing to note here: Please do not confuse between the ATmega and Arduino Pin numbers in the circuit diagram. Actually, the arduino's digital pin13(D13) is the ATmega chip's pin no. 19 and so on.. Dude, don't take this lightly or you're going to ruin your board!!
Lastly, check all the pins and solder points with continuity tester for any shorts or faults before succeding to next step!!

Step 4: Connect USB to UART Converter

It is the the device used as a communication medium between two brains i.e, Arduino and PC. There are many other types of converter modules available online. I used the CP2102 model from Silicon labs which has an integrated crystal too. Previous and newly arduinos used an RS232 type converter which uses a MAX232 chip and is very complicated and this is still used now by hobbyists. I would advice you to use USB types as its pretty easy and simple.

Connect 1st pin of module i.e, DTR pin to ATmega's 1st pin or Arduino's RESET pin through a 100nF capacitor.
Connect 2nd pin of module i.e, RXD pin to ATmega's 3rd pin(TXD) or Arduino's digital pin1(D1).
Connect 3rd pin of module i.e, TXD pin to ATmega's 2nd pin(RXD) or Arduino's digital pin0(D0).
Connect 4th pin of module i.e, VBUS to ATmega's 7th pin or Arduino's VCC pin viz the +5volt from USB port.
Connect 5th pin of module i.e, GND to ATmega's 8th pin or Arduino's GND pin.
Connect 6th pin of module to a +3.3volt power supply on Arduino viz not used so commonly.

The 3.3volt power is used very rare. Projects which use LCD, TFT screens, etc.. Are powered by this pin!

Step 5: Install the Softwares and Drivers and Get Started

Firstly, download the arduino IDE and then the driver for the converter. Without the driver your converter won't be detected by PC. Download and install the the softwares respective of your PC Operating System. For Arduino's software and more information, visit then start by testing simple LED programs to check if the arduino's working. If gotta problem and need troubleshooting, feel free to ask me.! :)