$20 LCR ESR Transistor checker project

[Radio Tech]

Is torch, the originator of this thread, still around?

It seems this well-developed (i.e., long ) thread would benefit from the addition of a summary section in the very first post to collect all the requisite and related info (or links thereto) in one place and then updated as new versions of hardware/software come out.

Would be nice to have all the information in one place and something to show what software goes with what hardware.
I still have this non-working unit that I think only needs reprogramming.



I am not very good when it comes to programming and need a noob tutorial. 

When power is applied and button is pressed you only get a bar across the screen.
I have tried to go through this thread to collect information but get pulled in other directions lol.

[madires]

When power is applied and button is pressed you only get a bar across the screen.

That's the case when the display isn't initialized. There are several posts in this thread about flashing the ATmega. An Arduino works as programmer too

[hapless]

When power is applied and button is pressed you only get a bar across the screen.

Does the microcontroller (or anything else) get warm while the screen is on?

[Radio Tech]

That's the case when the display isn't initialized. There are several posts in this thread about flashing the ATmega. An Arduino works as programmer too

I will search back through the threads and see what I can find. If I can ever learn this I will post a YT video showing how.

Does the microcontroller (or anything else) get warm while the screen is on?

From the beginning.  I picked the unit up to test a transistor one day. I noticed it did nothing. Screen did not come on and I did not feel any heat in the controller.  The day before I had checked some HV caps. Was thinking that perhaps one was not discharged. I ordered a second unit.

Many months later I took the bad unit out and tried to read the controller. Then I tried writing the programs to it. But not knowing what I was doing may have corrupted the controller. Again I am a total noob at trying to do this. But after my failure I noticed that when I press the button I get a bar across the screen now. So it does show some sort of life. Perhaps it is toast. I am not sure.

I continued to play with it and this came up :
"BAT 4.8V empty"
I tried to program again and only get the “bar” now. I put it aside till I could learn more about it.

[eas]

Assuming you are using a fresh battery, it sounds like either there is a problem with the voltage divider used to read the battery voltage, or the new firmware you installed isn't configured with the right divider ratio for calculating battery voltage (see BAT_NUMERATOR in the makefile).

[tom666]

From the beginning.  I picked the unit up to test a transistor one day. I noticed it did nothing. Screen did not come on and I did not feel any heat in the controller.  The day before I had checked some HV caps. Was thinking that perhaps one was not discharged. I ordered a second unit.

According to the above information, I guess that is damaged MCU (it must be replaced). For flashing just use any ISP programmer (for example the USBasp).

On this type of tester is appropriate to make the following changes:
- the addition of the blocking capacitor between AVCC and GND (resolve the problem with error message "Cell")
- replacement the zener diode D1 with the source of the precision voltage 2.5V
This adjustment is described in the official manual. In the attached pdf file is the extracted relevant section of the manual.

Procedure for flashing a firmware into MCU (ATmega328P) with the USBasp programmer:

Required hardware:
- USBasp (price around US $1.87)

Required Software (download links below):
- USBasp Driver
- AVRDUDE
- Firmware

1. Unzip the downloaded files into a separate directory and then perform the installation USBasp driver.
2. Then connect (through the ISP cable) the USBasp programmer with the ISP connector on the tester.
3. Navigate to the folder with the unpacked software and perform this following command from command line:
avrdude -c usbasp -p m328p --B 4.0 -e -U flash:w:"TransistorTester.hex":i -U eeprom:w:"TransistorTester.eep":i -U lfuse:w:0xF7:m -U hfuse:w:0xD9:m -U efuse:w:0x04:m
This command (also includes a section for writing fuses) can be copied and saved as e.g. "flash.bat" and stored in a prepared folder. In the future you can simplify this flashing of the firmware by the usage of "flash.bat".

Links:
USBasp - Driver:
http://www.fischl.de/usbasp/usbasp-windriver.2011-05-28.zip
or
http://www.protostack.com/download/USBasp-win-driver-x86-x64-v3.0.7.zip

AVRDUDE:
http://download.savannah.gnu.org/releases/avrdude/avrdude-6.1-mingw32.zip

Firmware:
http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328_2X16_menu/?view=tar

USBasp - How to install driver on Windows 8:
http://letsmakerobots.com/node/36841

USBasp - How to install driver on Windows 8.1:
http://openchrysalis.wordpress.com/2014/09/26/installing-usbasp-driver-software-in-windows-8-1/

USBasp - User Guide:
http://www.protostack.com/download/Users%20Guide%20(AC-PG-USBASP-UG-V2.0).pdf

[Radio Tech]

From the beginning.  I picked the unit up to test a transistor one day. I noticed it did nothing. Screen did not come on and I did not feel any heat in the controller.  The day before I had checked some HV caps. Was thinking that perhaps one was not discharged. I ordered a second unit.

According to the above information, I guess that is damaged MCU (it must be replaced). For flashing just use any ISP programmer (for example the USBasp).

Now that was an excellent post!

I too think the MCU could be bad. Perhaps it is just corrupt.
I have that same programmer here on my desk already.

Below is a pic on what this one does when you press the button.
Also my programmer.

[casinada]

I Have a tester just like that with a similar problem. I had to replace the Microcontroller.

[Radio Tech]

I Have a tester just like that with a similar problem. I had to replace the Microcontroller.

Think I will order a few of those controllers and give it a go also.

I just bought one of the new tester kit from banggood. Really like the way it works. I just uploaded a video on it.

I uploaded my video and put a thread here not to tie this one up:
https://www.eevblog.com/forum/other-blog-specific/diy-m12864-graphics-version-transistor-tester-kit-lcr-esr-pwm/new/#new

[Radio Tech]

Graham
Thanks for the reply on this. Great to know someone is close that knows a bit about these. I am headed out the door atm but reply back on this. Seems I can really use your help and perhaps you can teach this old dog a new trick. From previous test I think you are correct on it being a ATMega168. Would be nice to have it upgraded.
Really appreciate the information. Will get back with you.
Thanks   

[9a4wy]

Could someone compile hex+eep files from 1.19m for me??
I have no tool for this now 
tnx

[madires]

Could someone compile hex+eep files from 1.19m for me??
I have no tool for this now 

Please see http://www.avrtester.tode.cz/index.php?p=firmware (scroll down a little bit) for the classic edition.

[9a4wy]

uhhh...
tnx very much....I feel dumb now

[Radio Tech]

uhhh...
tnx very much....I feel dumb now

Dont feel dumb. This stuff can be difficult.
I cant even get the driver installed that tom666 posted 

[Radio Tech]

Spent the last 2 hours on the laptop I am trying to set this up on for programming.
Giving up on it. will try on a windows 7 machine this week end. Instructions for drivers says you have to disable driver signature enforcement for win 8.1.  When I get to that page pc freezes up and cannot do anything.  Other than that pc runs fine.

[AlxDroidDev]

This is one great thread.

I am reading through everything (from page 1) and deciding if I order one ($23 on DX, but will end up costing $55 due to taxes) or build my own. I haven't read everything yet, but has anyone here had success with a homemade tester?

[tom666]

I haven't read everything yet, but has anyone here had success with a homemade tester?

Some time ago I made the following variants of this tester (see attached pictures). The simpler (SCT v1.7) does not contain auxiliary power circuit. Switching on and off is complemented through a separate switch.

Many references can be found on this discussion forum (these are links after text "Podklady k vyrobe (DIY):"):
http://svetelektro.com/Forum/avr-component-tester-rlc-esr-semiconductors-tester-t30285.html

[madires]

I am reading through everything (from page 1) and deciding if I order one ($23 on DX, but will end up costing $55 due to taxes) or build my own. I haven't read everything yet, but has anyone here had success with a homemade tester?

Yup, please see http://www.mikrocontroller.net/svnbrowser/transistortester/Hardware/Markus/ for some inspiration

[lmester]

I just finished one of these kits. I noticed a few problems with it.

First the n (Nano) character is corrupted. See pictures. I'm guessing that the character data in the ATmega is corrupted.

After performing a few tests I also noticed that the ATMega is pulling the 2.5v voltage reference to ground. (Pin 27) It will briefly rise to the normal 2.5v level when taking a measurement. Also, if you boot it up directly into the menu the reference will stay at 2.5v until you've completed a measurement. Has anyone else seen this behavior?

I usually work with Microchip PIC's and don't have a programmer for the ATmega. I've ordered a cheap USBasp programmer from Ebay. I'm going to see if a reflash fixes any of the problems.

[papabol_24]

@tom666

hello tom, can u pls compile me a flipped fw of fish8840? thank you very much

[tom666]

I just finished one of these kits. I noticed a few problems with it.

First the n (Nano) character is corrupted. See pictures. I'm guessing that the character data in the ATmega is corrupted.

This cosmetic mistake I also registered.
The problem was solved by flashing a new firmware. On "banggood" I published instructions for updating firmware for this tester.
You can find it as 17 post at this link:
http://forum.banggood.com/forum-topic-92191.html?page=2

After performing a few tests I also noticed that the ATMega is pulling the 2.5v voltage reference to ground. (Pin 27) It will briefly rise to the normal 2.5v level when taking a measurement. Also, if you boot it up directly into the menu the reference will stay at 2.5v until you've completed a measurement. Has anyone else seen this behavior?

It's all right.

[tom666]

can u pls compile me a flipped fw of fish8840?

This is an original LCD or exchanged?
From which folder (SVN repositories) did you use the firmware?

[papabol_24]

Hello tom, this is a new unit from the seller that sent me the broken lcd  ive used the fw that u gave me on page 84, its the Fish8840_v1.12k_r554.zip

thank you

[papabol_24]

Hello Tom, the text is still flipped 

[tom666]

So try this