An how-to build an inexpensive Arduino Board for 5 USD.

1. Build your Arduino from
scratch
João Alves (jpralves@gmail.com)
Version 1.0 - Mar 2014

2. Agenda
Introduction
Problem
Solution
Requirements
Schematics
Bill of Materials
The Parts
Assembling the board
Running a Test Sketch
Demo

3. Introduction
Soldered my first Arduino Clone - a Diavolino (http://wiki.
evilmadscientist.com/Diavolino) - in 2012 in a workshop
presented by Mitch Altman at Codebits.

4. Introduction (cont…)
After some other workshops in Altlab (http://altlab.org)
where I assembled a Freeduino and made some small
stripboards with leds, buzzers and buttons I wanted to
do more and start learning not only the how but also
the why in electronics. This is one of my works, based
on several other similar projects found on the Internet.
You are free to use it, change it and improve it.

5. Problem
Arduino is very nice for prototyping but after creating a
project with the board it is an overkill to use it in the final
product. Although not very expensive, an Arduino clone
board costs at least € 20 (25 USD), an official one costs a
little bit more.

6. Solution
Create an inexpensive Arduino-like board that
can be used with the project keeping the
Arduino Board for future projects.
It can replace completely the Arduino board if
you don’t require the use of shields (it is not pin
head compatible).

7. Requirements
● Cheap
● Small
● Easy

8. Cheap
With a very small budget of up to € 3.5 (5 USD)
in parts it was possible to build this board with
the required components.

9. Small
To be small some optimizations were made to
the stripboard to accomplish its reduced size.
The board is 4.5cm x 5.5cm.
The circuit is adaptable to different
requirements and it was made modular enough
to be able remove the parts not needed and
reduce its size even further.

10. Easy
To be simple and easy to build I’ve used only THT -
Through-hole technology. Avoiding SMD - Surface Mount
Devices - components - as they are harder to solder and
prone to errors.
I’ve used the most common microcontroller used in Arduino
Boards with THT - the ATMega328P (in PDIP format). The
components where soldered to a stripboard to reduce extra
wiring.

11. Schematics

12. Bill of Materials
● 1x Stripboard with at least 19 Rows and 16
Columns (€ 0,73)
● 1x ATmega328P-PU microcontroller with
Arduino bootloader (U1) (€ 1,59)
● 1x 28 pin DIP IC Socket (U1)
● 1x 16 MHz crystal oscillator (XTAL1) (€ 0,44)
● 2x 22 pF, 50 V ceramic capacitors (C3, C4)
(€ 0,06)
● 1x 40-pin male single header (J1, J2, J3, J4,
J5, J6, J7) (€ 0,12)
● 1x 7805 linear voltage regulator (U2) (€ 0,22)
● 2x 100 μF, 25 V electrolytic capacitors
(C1, C2) (€ 0,04)
● 1x 1N4001 rectifier diode (D1) (€ 0,02)
● 1x SPST momentary normally-open type
switch (S1) € 0,08)
● 1x 10 kΩ resistor (R2) (€ 0,01)
● 1x 100 nF, 50 V ceramic capacitor (C5) (€
0,06)
● 1x 1 kΩ resistor (R1) (€ 0,01)
● 1x LED (3mm) (LED1) (€ 0,02)
● 1x Jumper (€ 0,01)

13. The Parts
● Voltage Regulator
● USB/FTDI Programming Header
● Hello World LED
● Microcontroller

14. The Voltage Regulator
Components:
● 1x 7805 linear voltage
regulator (U2)
● 2x 100 μF 25 V electrolytic
capacitors (C1, C2)
● 1x 1N4001 rectifier diode
(D1)
● 1x 5-pin male single
header (J5 + J6)

15. USB/FTDI Prog. Header
Components:
● 1x SPST normally-open
type switch (S1)
● 1x 10 kΩ resistor (R2)
● 1x 100 nF, 50 V ceramic
capacitor (C5)
● 1x 6-pin male single
header (J4)

16. Hello World LED
Components:
● 1x 1 kΩ resistor (R1)
● 1x LED (3mm) (LED1)
● 1x Jumper
● 1x 2-pin male single
header (J7)

17. Microcontroller
Components:
● 1x ATmega328P-PU microcontroller
(U1)
● 1x 28 pin DIP IC Socket (U1)
● 1x 16 MHz crystal oscillator (XTAL)
● 2x 22 pF, 50 V ceramic capacitors
(C3, C4)
● 1x 14-pin male single header (J1)
● 1x 7-pin male single header (J2)
● 1x 4-pin male single header (J3)

18. The ATmega328P Pin Layout

19. Assembling the board
● Tools required for assembling
● Preparing for the Assembly
● Cut holes in the stripboard
● Cut 40-Pin Header into smaller parts
● Soldering components

20. Tools required for assembling
● Soldering Iron
● Track Cutter
● Wire Snips
● X-Acto Knife
● Solder

21. Preparing for the Assembly
Common stripboards have one side with the “stripes” and
another clean side. The components will be mounted on
the clean side and soldered on the strip side.

22. Cut holes in the stripboard

23. Prepare 40-Pin Male Header
Cut the 40-Pin Male to this sizes:
● 1x 14-pin male single header (J1)
● 1x 8-pin male single header (J2)
● 1x 4-pin male single header (J3)
● 1x 6-pin male single header (J4)
● 1x 5-pin male single header (J5 + J6)
● 1x 2-pin male single header (J7)

24. Soldering components
Solder the components in the
following order:
● Wires
● IC Socket (U1)
● Resistors (R1, R2)
● 1N4001 (D1)
● Ceramic Capacitors (C3, C4, C5)
● Crystal (XTAL)
● SPST switch (S1)
● Male Head Pins (J1, J2, J3, J4,
J5, J6, J7)
● LED (LED1)
● Electrolytic Capacitors (C1, C2)
● 7805 (U2)
● ATmega328P (U1)

25. Components location
● IC Socket and ATmega328P-PU (U1)
● 16 MHz Crystal (XTAL1)
● 22 pF, 50 V (C3, C4)
● 7805 (U2)
● 100 μF, 25 V (C1, C2)
● 1N4001 (D1)
● SPST switch (S1)
● 10 kΩ resistor (R2)
● 100 nF, 50 V (C5)
● 1 kΩ resistor (R1)
● LED (3mm) (LED1)
C5
C3
C1 C2
C4
XTAL1
S1 U1
U2 D1
LED1
R1
R2
FTDI
POWER

26. Soldering components location
After each component there are coordinates LyCx where y is the line and x is
the column to put the wire.
The lines and columns are numbered on the strip side so the x is backwards.
x
y

27. Wires
Cut wires with the following lengths:
● Black:
○ 2 x 3 cm (L4C3-L12C3, L4C8-L13C8)
○ 1 x 1 cm (L2C9-L4C9)
● Red:
○ 2 x 3 cm (L5C2-L14C2, L5C6-L12C6)
○ 2 x 1 cm (L3C12-L5C12, L5C14-L6C15)
● Green:
○ 1 x 3,5 cm (L3C5-L15C5)
● Yellow:
○ 1 x 3 cm (L6C13-L11C16)
Solder the wires into the stripboard according to the image.

28. IC Socket (U1)
Place the IC Socket with pin 1 on the top.
Its not very easy to solder because the two wires below get in
the way. Try to center the wires under the socket.
Solder carefully according to the image.
Components:
● U1 - 28 pin DIP IC Socket (L6C7 - L19C4)

29. Resistors (R1, R2)
The Resistors don’t have polarity but R1 is different from R2.
Solder carefully according to the image.
Components:
● R1 - 1 kΩ resistor (L3C3 - L2C5)
● R2 - 10 kΩ resistor (L6C9 - L12C9)

30. 1N4001 (D1)
Solder the component in the board with the stripe (-) on the
left.
Components:
● D1 - 1N4001 rectifier diode (L1C2 - L1C5)

31. Ceramic Capacitors (C3, C4, C5)
The Ceramic Capacitors don’t have polarity but C5 is different
from C3 and C4. Solder carefully according to the image.
Components:
● C3 - 22 pF, 50 V ceramic capacitor (L13C11 - L15C11)
● C4 - 22 pF, 50 V ceramic capacitor (L13C9 - L14C9)
● C5 - 100 nF, 50 V ceramic capacitor (L9C15 - L11C15)

32. Crystal (XTAL)
The Crystal doesn’t have polarity. Solder carefully according
to the image.
Components:
● XTAL - 16 MHz crystal oscillator (L14C8 - L15C8)

33. SPST switch (S1)
To solder this component you should straighten the pins so it
fits in a 3 x 3 space. Solder carefully according to the image.
Components:
● S1 - SPST normally-open type switch (L11C14 -
L13C12)

34. Male Head Pins (J1, J2, J3, J4, J5, J6, J7)
These should be soldered carefully. Solder only one pin at
the beginning so its easier to straighten the head, then solder
the rest.
Solder carefully according to the image.
● J1 - 14-pin male header (L6C1-L19C1)
● J2 - 8-pin male header (L6C10-L13C10)
● J3 - 4-pin male header (L16C10-L19C10)
● J4 - 6-pin male header (L4C16-L9C16)
● J5+J6 - 5-pin male header* (L1C1-L5C1)
● J7 - 2-pin male header (L2C6-L3C6)
* - Remove 2 of the pins

35. LED (LED1)
The LED has a longer leg (+) which should be placed on the
upper side, the smaller leg (-) should be on the bottom side.
Solder according to the image.
Components:
● LED - LED (3mm) (L3C2+ - L4C2-)

36. Electrolytic Capacitors (C1, C2)
The C1 should have the (-) side up and the (+) side down.
The minus is normally identified by a white strip and shorter
leg.
The C2 should have the (-) side down and the (+) side up.
Solder according to the image.
Components:
● C1 - 100 μF 25 V electrolytic capacitor (L2C13- -
L2C13+)
● C2 - 100 μF 25 V electrolytic capacitor (L1C8+ - L2C8-)

37. 7805 (U2)
The metal side should be facing right and letters on the chip
should be facing left. Solder according to the image.
Components:
● U2 - 7805 linear voltage regulator (L1C10-L3C10)

38. ATmega328P (U1)
Then, after finishing you can put the ATmega328P on the
socket according to the image.
Components:
● U1 - ATmega328P-PU microcontroller

39. Fully assembled board

40. Testing and using it
Make sure you don’t have shorts between
tracks
Use a USB/FTDI Breakout board
Disconnect the external power to the board when using the
USB/FTDI programming breakout card.

41. Running a Test Sketch
Setup Arduino IDE:
● Choose Arduino Duemilanove w/ ATmega328
● Load Examples -> 01. Basics -> Blink

42. Demo
● Traffic Signals
● MegaDemo
● Ultrasonic Sensors

43. Q & A ?
Questions ?
http://jpralves.net
https://plus.google.com/u/0/+JoãoAlvesPlus