$20 LCR ESR Transistor checker project

[mauroh]

Thanks bitseeker, that's exactly what I was looking for.

I'm still considering making my own though. I will share my design if I manage to do it.

The current hardware design is available assembled and as DIY Kit for less than 10$...
If you really want to design your own, consider at least to use a bigger microcontroller.

The current firmwares M and K are using almost all the resources of the Atmega328p and with all the option enabled you will run out of flash and/or GPIOs.

The current firmwares supports already the Atmega644 and I think madires is working on a Atmega1284 hardware (looking forward for that!!).

Since I like all the options that require additional hardware like IR decoder, Zener Tester, tachometer, SuperCAP Tester.... I was thinking to use an ArduinoMega2560 board and build a custom shield with a color LCD and all the hardware to support all the firmware option.

Or alternatively design a ESP32-WROOM-32 based board.
It has a lot of horse power, bluetooth, WiFi and enough GPIO to connect all possible hardware options   

Mauro

[madcat]

sorry for not being clear. 

yes, Mauro got my question right.
i mean put the blank atmega328p chip on arduino uno, and program it using usbasp.
if i remember correctly, arduino uno board also has 16mhz crystal onboard, though i don't really know if it has relevancy in programming process or not.

thank you all. 

[linux-works]

I'm hoping that this project can get ported over to the 'blue pill' ARM board.  those are now like $5 each or less and they have 128k of flash, plus 10 12-bit a/d ports!

[madires]

The problem with another MCU family is Vcc. We need 5V! For a MCU running at 3.3V or so we would have to add external switching, i.e. for each test resistor and probe pin. That would also imply an external ADC, unless the internal one supports voltages above Vcc.

[bitseeker]

Since I like all the options that require additional hardware like IR decoder, Zener Tester, tachometer, SuperCAP Tester.... I was thinking to use an ArduinoMega2560 board and build a custom shield with a color LCD and all the hardware to support all the firmware option.

Yes! I was thinking the same thing, a shield for the Arduino Mega 2560. I have one ready to become a host to such a shield. And a 3.5" color LCD shield to go on top.

Or alternatively design a ESP32-WROOM-32 based board.
It has a lot of horse power, bluetooth, WiFi and enough GPIO to connect all possible hardware options   

Isn't that only 3.3V?

[mauroh]

Yes, 3.3V only but I love it.
Didn't know that was an issue, I'll read the documentation...
Mauro

[ebclr]

In fact 3.3V can be nice, because will force to use a driver, and a high voltage driver with 10 / 20 vcc range will permit a new range of components to be tested, or even better a variable voltage driver

[qu1ck]

I believe I made the perfect tester for me.
The banggood m328 kit for $18 that comes with the case is pretty good, it even comes with 0.1% measurement resistors unlike some other kits. I just wasn't happy with their included front panel. Why waste a perfectly functional zif panel?
Also I wanted to get rid of the 9v power and use li-ion battery pack instead.
Here is the result:
http://imgur.com/a/39QZE
I forgot one modification on the picture. The resistor between 9012 base and power led anode, 3.3k one should be replaced with 1k. This is needed to keep the 9012 base current at 2-3ma. Without it I had significant voltage drop across emitter-collector.
Also put some capacitance on the step-up module input as seen on the pictures, I used 100uF. It is not needed if you use high frequency converter IC, but mine seems to be 2.5khz and without that cap voltage on the collector of 9012 was sagging slightly every time the mosfet of the boost converter was on.

The 2mm banana jacks are also a nice addon.

The precompiled firmware 1.13k with lower battery cut-off (3.1v) can be found here along with avrdude command and modified makefile http://s000.tinyupload.com/?file_id=01021722150636328454

[steffenmauch]

Can someone tell me what the limiting factor regarding measuring lower inductance is?
Thus, measuring 1uH e.g.

Thanks.

[madires]

In fact 3.3V can be nice, because will force to use a driver, and a high voltage driver with 10 / 20 vcc range will permit a new range of components to be tested, or even better a variable voltage driver

Higher and variable voltages and currents would be great to check more components and to measure more parameters. The downside is that the circuit would grow significantly and the firmware too. The current simple circuit hits the sweet spot of cost, simplicity and functionality. I don't have any idea if there will be some kind of Tester+ in the future. For the moment we concentrate on the classic ATmega 328 and the 644/1284s.

BTW (m-firmware), I've reworked the velocity sensing for the rotary encoder and added a way to finetune it. Right now I'm adding support for up/down push buttons as alternative to a rotary encoder, possibly with a speed-up function similar to the encoder's turning velocity.

[madires]

Can someone tell me what the limiting factor regarding measuring lower inductance is?
Thus, measuring 1uH e.g.

The limiting factors for the inductance measurement are time resolution and current, which allow measurements down to about 10µH. The sampling ADC method (LC tank) can measure down to 100nH or so.

[ebclr]

while people have time and resources to do this




People,  Time and resource to do a tester + will appear, I am very interested in port the tester to ESP32, but need some help from other  people who share the same goal

[rrinker]

hi,
i just bought some blank atmega328p chips to try 16mhz crystal upgrade on the AY-AT model.
does the chip programming can be done on arduino uno board with usbasp programmer?

Do you mean using the Arduino as the programmer (using ArduinoISP sketch) and a breadboard or using a USBasp programmer on an arduino with a blank chip? The former is definitely possible, but you'll need a crystal oscillator set up at the same frequency on the breadboard or wherever you program it. The latter I think should also work, provided the crystal is the same frequency but I've never tried it.

 Yes, this works quite well actually. I was doing some stuff with ATTiny85's so I built a shield witht he circuit on it and a socket for the 8 pin MCUs, but I also used it to load new firmware on the ATMega 328P for my tester, just ran some wires over to a breadboard, and plugged in a 16MHz crystal with a pair of 22pF caps. The Arduino as ISP sketch to load on the Uno is included in the IDE. You can then use the Arduino IDE to load code into the downstream micro, or if you have object files you can just push them with Avrdude. I cheated and used AvrdudeSS to use the GUO to control it. For a programmer you actually pick AVRISP and by default it operated at 19200 bps. The sketch even has allowances to set up some indicator LEDs, which I did with my shield, there's a heartbeat LED, a programming LED to show data flow, and an error LED to indicate a problem.

[macinblack]

Hi guys, I want to buy one cheap LCR until 20€, it this LCR (LCR-T1) the best: https://goo.gl/w7WKWQ ? Thanks 

[madires]

That was answered one page back

[ebclr]

Same but cheaper free shipping

https://pt.aliexpress.com/item/2017-LCR-TC1-Transistor-Tester-TFT-Diode-Triode-Capacitance-Meter-LCR-ESR-NPN-PNP-MOSFET/32783823366.html?spm=2114.02010208.3.2.q2CArZ&ws_ab_test=searchweb0_0,searchweb201602_2_10152_10065_10151_10068_10136_10137_10060_10138_10062_10153_10141_10056_10055_10054_10059_124_10099_10103_10102_10096_10148_10147_10052_10053_10142_10107_10050_10143_10051_10084_10083_10080_10082_10081_10110_10111_10112_10113_10114_10037_10032_10078_10079_10077_10073_10070_10123_10124,searchweb201603_6,afswitch_1,ppcSwitch_5&btsid=a8e89a6c-7ba4-4ef5-a037-7814472ec88a&algo_expid=150ba60d-b0b9-40e4-91ea-7d4eb476716d-0&algo_pvid=150ba60d-b0b9-40e4-91ea-7d4eb476716d

[mauroh]

It is awesome!!
I tested the servo function on the m-firmware by madires...
It is possible to increase the pulse width by 0.01ms for each step of the rotary encoder 

Just for fun I speed up an old HDD at 10200RPM with an ESC connected to the Transistor Tester and measured the speed with a laser-oscilloscope tachometer 

Thank you Markus for the great job (hope you don't mind I mentioned in the video description, If you prefer I can change it).

Mauro

[madires]

I've just released 1.28m. Highlights:
- Russian
- rotary encoder's velocity sensing reworked
- support of fixed cap for self-adjustment
- increase/decrease push buttons as alternative for rotary encoder (including speed-up functionality)

[pepe10000]

I've just released 1.28m. Highlights:
- Russian
- rotary encoder's velocity sensing reworked
- support of fixed cap for self-adjustment
- increase/decrease push buttons as alternative for rotary encoder (including speed-up functionality)

Tested on an LCR-T4-H and all O.K.

A greeting.

[macinblack]

That was answered one page back

Thanks, I ordered one. Where can I find the last firmware?

[hapless]

I've just released 1.28m. Highlights:
- Russian

Windows-1251 with no conversion table for 1602, cemented inside a font?   

BTW, what tool was used to create the fonts originally?

[casinada]

I got the AY-AT version of the tester. It came with the 1.12K firmware version.
I was able to program the 1.13K version using the HEX and EEP files downloaded from the software repository.
Next I wanted to try the 1.27m version but I couldn't compile anything on my windows 10 computer using WinAvr. I tried FlyWheelz instructions but they didn't work. I gave up and used a Windows 7 32 bit computer where I had all the software but hadn't used for a long time. I was able to modify the K code and compile it successfully but it was creating very big code that wouldn't fit on the Atmega 328P.
After more reading and searches on the internet I downloaded Cygwin (64 bit in my case), installed on the windows 10 machine and modified the computer path to include the cygwin64\bin folder. I was able to compile without any problems and most of the code generated fits on the microcontroller. Finally I was able to compile the 1.27m firmware and today the 1.28m for the AY-AT board.
I found some discrepancies with the different firmware versions:
I like how the K versions show more information when testing components such as transistors. Is it possible to modify the m version to include that information?
The m version code is more organized and easier to follow.
When testing a PN4117A the only firmware that shows correct information is on the m versions. At least from version 1.25m and up ( I haven't tested older versions)
The 1.12K version thinks that is a double diode. The 1.13K version thinks that is a transistor. The 1.28m version thinks that is an N-channel JFET with Idss=75ua. I know that Marcus code can detect JFETs with very low Idss.
 I also have a Peak DCA75 and it detect the part as a double diode. I haven't contacted them to see if they can modify the code to recognize the JFETs with low Idss.
Thank you to Markus and Karl for continuing the work of Markus Frejek and for being so available to help the comunity.

[Willem52]

The repository of the software is here:
https://www.mikrocontroller.net/svnbrowser/transistortester/Software/

[madires]

And there's a mirror on github: https://github.com/svn2github/transistortester

[madires]

Windows-1251 with no conversion table for 1602, cemented inside a font?   

BTW, what tool was used to create the fonts originally?

Be my guest Neither do I speak Russian nor do I have a HD44780 compatible LCD with a Russian font. If someone sends me a font_HD44780_cyrillic.h I'll happily add it to the source. I don't know which tool was used to create the 8x16 Cyrillic font. Maybe indman got an idea.

PS: I can provide a tool (linux) to convert bitmap fonts between different alignments and bit orders.