Introduction: Component Tester - Test Almost Anything !!

Picture of Component Tester - Test Almost Anything !!

Being an Electronics student or hobbyist, you may have thought of getting a tester that could test almost anything "THE ELECTRONICS COMPONENTS, OBVIOUSLY!!"

Now what if I tell you that you can have one and that too made by yourself under INR 600 only (USD 10).

Coming upon COMPONENT TESTER so it can test almost everything, obviously not the power components because they require more current and power which our AVR Microcontroller couldn't handle !! Oh yeah, I forgot to tell you guys that we would be using an ATMEGA328 for our build !!

Yes, the same microcontroller which an arduino uno uses...!!

So, here's what our Component Tester can test -

1. Resistors

2. Capacitors along with their Equivalent Circuit Resistance Value (ESR)

3. Inductors

4. BJTs

5. FETs

  • JFETs

6. Thyristors

  • SCRs
  • DIACs
  • TRIACs

7. IGBTs

8. Diodes

no the list doesn't end here.... it can test Voltage upto 50V, it has a FREQUENCY COUNTER and a FREQUENCY GENERATOR TOO :D

you can also detect the IR Codes by simply putting a TSOP Sensor on its test pins.... isn't that great :D

and yeah one thing i forgot to tell you guys it doesn't only detect the components it displays their respective values and properties too !!

No, don't thank me for such wonderful thing thank MARKUS F. the maker and developer of Component Tester and Karl-Heinz who developed the firmware for it.

Let's Start the build and you'll explore much more on the way to build your own..!!

Step 1: Order Stuff for Build !!

Picture of Order Stuff for Build !!

with some basic components and tools you will be ready to build...!!

Electronic Components

  • 1x 1nF (102) Ceramic Capacitor
  • 1x 10nF (103) Ceramic Capacitor
  • 4x 100nF (104) Ceramic Capacitor
  • 2x 22pF (22) Ceramic Capacitor
  • 2x 2.2uF, 50V Electrolytic Capacitor
  • 2x 1N5819 or any other Schottky Diode with current rating of 1A
  • 1x 7805 - 5V Voltage Regulator
  • 1x LM336 - 2.5V Voltage Reference Diode
  • 1x 10uH Inductor
  • 1x BC547 Transistor
  • 1x BC328-40 Transistor
  • 3x 680 ohm Resistor with 0.1% Tolerance (1% Tolerance would also do)
  • 3x 470k ohm Resistor with 0.1% Tolerance (1% Tolerance would also do)

NOTE: For 1% Tolerance and 5% Tolerance(not recommended but works with less accuracy) 680 ohm and 470k ohm resistors you need to make some changes in code and try to have all resistors indicating same value on multimeter.

UPDATE: For those who are having problems in finding 0.1% or 1% tolerances. You can use 5% tolerances. Just buy 5-7 resistors of 5% tolerances and find out 3 resistors having same value on the multimeter. I made another one for you guys with 5% tolerance resistors and changes the value of resistors in code and that worked too :)

  • 2x 3k3 ohm resistor
  • 2x 27k ohm resistor
  • 1x 100k ohm resistor
  • 1x 33k ohm resistor
  • 6x 10k ohm resistor
  • 1x 470 ohm resistor
  • 1x 15k ohm resistor
  • 1x 2k2 ohm resistor
  • 1x 200k ohm resistor
  • 2x 1k ohm resistor
  • 2x 10k ohm preset (Variable Resistance)
  • 1x 8MHz Crystal Oscillator
  • 1x ATMEGA 328/328p with Socket
  • 1x Rotary Encoder w/ Button Module and KNOB
  • 1x Red LED (you can use any colour I chose Red as it it used to denote POWER)

Hardware Parts

  • 1x 16 Pin Polarized Header Cable - Relimate Connectors
  • 3x 3 Pin Polarized Header Cable - Relimate Connectors
  • 2x 4 Pin Polarized Header Cable - Relimate Connectors
  • 1x 9V Battery Connector
  • 6x Banana Jack Connectors (Female)
  • 3x Banana Jack Connector Cable (with Male Heads)
  • 1x Enclosure Case (I used a plastic Switch Board Enclosure Case/ Plastic Project Box)

Tools Required

  • Soldering Iron
  • Some Solder
  • A Single Layer PCB (because I home etched mine for this as it reduces unwanted signals and noises in the circuit and being it a testing circuit etching your own PCB is advised for getting accurate results)
  • Solder Mask (optional)
  • Some strong cutters (to make cutouts on you enclosure)
  • Screwdrivers and Pliers
  • and some ISO-PROPYL Alcohol or Acetone would work fine to clean the flux residue on PCB (It its necessary that you clean the flux or it may cause some unwanted errors in your Component Tester).

Let's Start the build !!

Step 2: Schematics and PCB Build !!

Picture of Schematics and PCB Build !!

This is a self designed and home etched PCB...!!

I used eagle software freeware version for designing PCB. I have attached the PCB (un-mirrored) files below so you can download and etch them at home. For etching you can refer to other instructables on how to go about etching process using Ferric Chloride(FeCl3).

You can Follow GreatScott's series on how to etch PCB's using Ferric Chloride-



UPDATE : I've uploaded Eagle Files :)

Step 3: Applying the Solder-Mask Onto PCB (OPTIONAL)

Picture of Applying the Solder-Mask Onto PCB (OPTIONAL)

If you wish to apply solder mask u can follow the below video on how to go about applying solder mask.

I have attached the pad mask so to resist application of solder mask on component pads.

Step 4: Drilling Holes on PCB

Picture of Drilling Holes on PCB

For drilling holes on PCB you can either use a hand drill or a electric drill / drill press.

Step 5: Soldering Components on PCB

Picture of Soldering Components on PCB

Be careful while soldering the 680 ohms and 470 kilo-ohms resistor which are test resistors !!

  • Do not apply more solder on these resistors as that can induce some unwanted capacitance or resistance in the circuit.
  • Do not leave flux on the PCB after soldering components !! This may result in some unwanted values u see on display. You can use Isopropyl Alcohol and some Cotton Buds to clean the flux on PCB.

Step 6: Preparing the Enclosure...!!

Picture of Preparing the Enclosure...!!

I used a plastic project box as enclosure for my COMPONENT TESTER...!!

I drilled holes for binding posts and DC jack socket then used a hot knife to make cutout for 16x2 LCD.

NOTE : desolder the grounded leg of push-button on rotary encoder module and connect that to positive side of LED along with wires coming from the PCB


  • PIN1 - LED Negative
  • PIN2 - LED Positive
  • PIN4 - +5V

Connect 2nd Pin of switch to LED Positive

Step 7: Uploading the Code to AVR

Picture of Uploading the Code to AVR

The code files are attached below as .zip file format so that you can compile an build code after making the necessary changes in configuration files.

Now open up config.h and make the following changes -

  • navigate to measurement settings and offsets
    • now in this section scroll to R_LOW and set the value of 680 ohm resistance you are getting on you multimeter try and choose 3 680 ohm resistance with same values showing on multimeter
    • now change the value of R_HIGH i.e. the value of the 470k ohm resistances you are getting on your multimeter be as precise as possible and try and choose 470k ohm resistances with closest values or same values showing up on multimeter.
    • change RH_OFFSET if you want or leave it as it is. RH Offset is Offset for systematic error of resistor measurement with Rh (470k)
    • change R_ZERO - Resistance of probe leads (in 0.01 Ohms).
      • Resistance of two probe leads in series. (Assuming all probe leads got same/similar resistance)
    • change CAP_WIRES - Capacitance of the wires between PCB and terminals (in pF).
      • 2pF for wires 10cm long
    • change CAP_PROBELEADS - Capacitance of the probe leads connected to the tester (in pF).
      • 3pF for about 10cm long probe leads
      • 9pF for about 30cm long probe leads
      • 15pF for about 50cm long probe leads
    • you can go through rest of values and play-around if you are familiar with AVR and coding. If not please do not alter anything else.

If you are facing problems opening .zip files I am sharing the Dropbox link to code -


UPDATE: If you are using usbasp programmer then you need not edit the Makefile else you need to goto line 54 and change

programmer = usbasp to programmer = <your programmer's name>

  • open command window in that folder where you have your code by holding shift and right click you will see an option of Open Command Window Here click that
  • type in make all
  • connect the Programmer with the ISP Header of Atmega328
  • type in make upload
  • then type make fuses
  • following to this type make clean

NOTE : I assume that you have avrdude pre-installed in your systems. if not youhave to download avrdude and install it before doing above steps.

Step 8: Assembling Everything As One Device

Picture of Assembling Everything As One Device

Before assembling just run everything and test one or two components so as to confirm everything is working fine.



So you made one component tester for yourself.... you can keep that handy on you workbench and use it to test your components more often...

UPDATE : You can see the menu for the tester which includes PWN Generation, Square Wave Generation, Frequency Counter, IR Code Detector, Calibration and Adjustment Menu by turning the rotary encoder left after turning the tester on.


PaulC175 (author)2017-09-10

Hi, Excellent project

I am using atmega328p-pu 20mhz, 8mhz crystal, programmed micro via your arduino trick, i have built this twice to get same problem.

lcd is showing 2 full rows of full char 255(FF). i have tried 6 different lcd's to get same problem, any help would be appreciated.


PirateKittyK (author)PaulC1752017-10-08

Did you try the pot for the LCD contrast? Too much contrast does that too.

PaulC175 (author)PirateKittyK2017-10-08

works out it was eeprom not programmed, so showing FF hex.

when i figured eeprom not programmed it cured problem

mosfet06 (author)2017-09-04

I made the project on this site, but I could not work it,

I guess I did not succeed in installing the software,

I use the AVRUDE program, please help me,

at least the proteus simulation can be run

Please allow me to send the code and files of the rest of the success myself, proteus atmega328 and lcd work.

please help me to run it,

Thank you ,

PirateKittyK (author)mosfet062017-10-08

Don't bother asking for help. This guy won't help you. He just wants praises.

PaulC175 (author)2017-09-12



Please i need help to connect the encoder, i have tried in different ways and I have not been able to.

have you got 2 x 10k resistor pullups to 5v

jolealca (author)2017-09-11

Please i need help to connect the encoder, i have tried in different ways and I
have not been able to

GustavoR93 made it! (author)2017-02-14

I made it works great!, except for inductance measurement, always show the same value.

I am using internal 8Mhz i don't have 8Mhz crystal.

baweja_akshay (author)GustavoR932017-08-27

looks great !!

GustavoR93 (author)2017-02-26

Hi Baweja, are you tried to measure an inductor? i dont see any in the pictures.

baweja_akshay (author)GustavoR932017-08-27

yeah I did measure inductor. It is there in pics check again. let me know if any problem occurs.

aeroslubis (author)2017-03-17

Hi, Can disable the auto turn-off function on the code?

baweja_akshay (author)aeroslubis2017-08-27

yes you can disable that in config file

vcrahul (author)2017-03-17

I made one and it works like a charm. So firstly I should say thanks for sharing such a nice project.

Iam getting exact values for resistance measurement. But for capacitor104 it shows value as 4560pf. So how can I calibrate the cap values. Kindly reply. Thanks

baweja_akshay (author)vcrahul2017-08-27

while testing capacitances sometimes probes can create a problem. correct your probe capacitance in config file. It'll work perfectly.

ramchandrar1 (author)2017-03-20

i am new to "AVRDUDE" do i need additional hardware to upload the program and which file do i need to upload

follow the instruction on how to use makefile in above instructable.

HikariH1 (author)2017-06-02

There many file code. I'm confused that what should be use to programme my IC. Please help me. I'm have a problem with programming code

baweja_akshay (author)HikariH12017-08-27

you have to use make file for programming you uC.

marsekal (author)2017-06-04

mr. good job link file hex 328 mr thanks...

baweja_akshay (author)marsekal2017-08-27


All files are at the dropbox link. Please check

Happy Making !!

AshokK56 (author)2017-06-06

Dear sir kindly tell me how to Program step by step guide Plesae please sir,

kindly tell me what is the error in the following

AVR Memory Usage

Device: atmega328

Program: 22842 bytes (69.7% Full)

(.text + .data + .bootloader)

Data: 175 bytes (8.5% Full)

(.data + .bss + .noinit)

EEPROM: 784 bytes (76.6% Full)


avrdude -c usbasp -B 5.0 -p m328p
-P usb \ -U flash:w:./ashok.hex:a -U

avrdude: set SCK frequency to
187500 Hz

avrdude: warning: cannot set sck
period. please check for usbasp firmware update

avrdude: error: programm enable:
target doesn't answer. 1

avrdude: initialization failed,

Double check connections and try
again, or use -F to override this check.

avrdude done. Thank you.

make: *** [upload] Error 1

baweja_akshay (author)AshokK562017-08-27

Your clock frequency isn't set properly. Set it accordingly and try again it'll work.

mashroti (author)2017-07-07

pls send me hex and epp file and fuse bit for mega 328p

baweja_akshay (author)mashroti2017-08-27


All files are at the dropbox link. Please check

Happy Making !!

drlvenkatesh (author)2017-07-21

Hello Akshay. Its a nice project. Can you guide me the same project with readymade arduino uno/nano and lcd + other components needed.

This is not arduino compatible but yeah you can always contribute by coding it for arduino. :)

Happy Making !!

MojtabaJ5 (author)2017-08-01

i need hex of this device

baweja_akshay (author)MojtabaJ52017-08-27


All files are at the dropbox link. Please check

محمدط6 (author)2017-05-17

hello, thanks for your effort.

what are the alternatives to 2.5v-lm336 or lt1004? what is it's purpose?
like some zener or "variable zener" with transistor..etc.

because I could not find it in local stores.

محمدط6 (author)محمدط62017-05-18

and by the way how much is the accuracy of this device?!

tolerance of 1%

lm336-2.5 موجود في باب اللوق

عند الجمال و mtm

CESARG38 (author)2016-12-15

Please you can send me the schematic and the pcb to, thanks

baweja_akshay (author)CESARG382017-01-18


schematic and other details are already attached in the instructable you can download from there.

star3151 (author)baweja_akshay2017-08-21

hi 1year ago i want this tester hex file and you tell me ok isend you

but dont send i can not make hex file please help me

baweja_akshay (author)star31512017-08-27

@star3151 - Hey!! All files are in dropbox link.. Please check I notified this before also. :)

Happy Making !!

R4MP4G3RXD (author)2017-05-16

Hello! Awesome project, I've made mine but it isn't working. When I try to make fuse bits i get an error, I'm using an atmega 328p(did the same with a 328), WinAVR and my usbasp is connected to the programing header. What could be the problem?


avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x0000
0xfc != 0x04
avrdude: verification error; content mismatch

avrdude: safemode: efuse changed! Was fc, and is now 4
Would you like this fuse to be changed back? [y/n] n //If I put in 'y', than it just freezes in that position until I disconnect the programmer.
avrdude: safemode: Fuses OK


AshokK56 (author)R4MP4G3RXD2017-08-12

iam also having the same problem did you solve it kindly tell me please? thank you

MauroP4 (author)2017-02-20

all ok but inductance as the same behavior as GustavoR93

thanks Baweja

GustavoR93 (author)MauroP42017-02-26

Hi, are you using 8Mhz crystal?, i am using internal 8Mhz oscillator because i dont have an 8Mhz crystal.

PriscellaO (author)2017-02-10

hello, please how do i upload all the files in the zip file onto the micro controller?

i saw it up there that use avrdude .....but am new to programming so if someone can actually take me step by step on how to upload all the files.

domdomgin (author)PriscellaO2017-02-11

what programmer do you have.

you need to unzip the files.

make a folder put all the files in that folder.

install avr dude.

connect the usbtiny programmer to your board.

make sure you change the programmer name in the makefile

right click in the folder and open command window.

type the commands which is mentioned in this tutorial.

it will work.

PriscellaO (author)domdomgin2017-02-16


domdomgin (author)2017-01-03

Please can someone tell me the fuse bits..

GustavoR93 (author)domdomgin2017-02-15

You can see the fusebits in the file makefile for different oscillators:

# ATmega328 / ATmega328P

ifeq (${MCU},atmega328)

HFUSE = -U hfuse:w:0xd9:m

EFUSE = -U efuse:w:0xfc:m

ifeq (${FREQ},1)

# internal RC oscillator (8MHz) and /1 clock divider

LFUSE_RC = -U lfuse:w:0x62:m

# external 8MHz full swing crystal and /8 clock divider

LFUSE_CRYSTAL = -U lfuse:w:0x77:m

# external 8MHz low power crystal and /8 clock divider

LFUSE_LOWPOWER = -U lfuse:w:0x7f:m


ifeq (${FREQ},8)

# internal RC oscillator (8MHz) and /1 clock divider

LFUSE_RC = -U lfuse:w:0xe2:m

# external 8MHz full swing crystal and /1 clock divider

LFUSE_CRYSTAL = -U lfuse:w:0xf7:m

# external 8MHz low power crystal and /1 clock divider

LFUSE_LOWPOWER = -U lfuse:w:0xff:m


ifeq (${FREQ},16)

# internal RC oscillator (8MHz) not possible


# external 16MHz full swing crystal and /1 clock divider

LFUSE_CRYSTAL = -U lfuse:w:0xf7:m

# external 16MHz low power crystal and /1 clock divider

LFUSE_LOWPOWER = -U lfuse:w:0xff:m





brianlutruntuhuluy (author)2017-02-11

hello, please i want to know overall block diagram of this component tester ?

domdomgin (author)2017-02-09

how do you switch on the unit.also the start button goes to gnd not +5 am i right.

About This Instructable




Bio: your best teacher is your last mistake !! - Dr. APJ Abdul Kalam
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