Author Topic: $20 LCR ESR Transistor checker project (Read 3452942 times)

bitseeker · « **Reply #2025 on:** May 06, 2016, 09:10:49 pm »

That's a nifty idea for frequently taking the mcu in/out.

JacquesBBB · « **Reply #2026 on:** May 07, 2016, 02:09:00 am »

I did that because at the begining i had to make modifs of the code for this model to have the proper display. The zif socket just fitted.

morbid80 · « **Reply #2027 on:** May 08, 2016, 02:21:29 am »

Quote from: SirKnowsALot on May 05, 2016, 08:34:03 pm

I tried reflashing with 1.12k_r453 prebuilt by Tomas (https://www.mikrocontroller.net/topic/248078?goto=4120737#4105488) which turned the backlight on but nothing more. I was able to flash the code I originally extracted back and at least it works again. When I get some more time I will look more closely at the makefile and build my own version. It is good to know that if you can get the original code out of the tester you can use it for disaster recovery.

i got a similar tester like yours.lcr-T3. if u manage to build a working firmware for this model, do share it with us. still waiting for my programmer from aliexpress

SirKnowsALot · « **Reply #2028 on:** May 08, 2016, 12:29:00 pm »

Will do. I rebuilt code from mega328_T3_T4_st7565 which resulted in the same issue, and I tried to build m-firmware (I'm not sure I did it correctly, but it compiled) and I still got the backlight-only result.

I thought I would next trace out the circuit to see if it deviates from the standard design somehow.

I extend the challenge and invitation to anyone with this same tester (http://www.ebay.com/itm/221961865013) to share any experience.

madires · « **Reply #2029 on:** May 08, 2016, 12:59:36 pm »

Is the display of your tester ST7565 compatible? Maybe it got some other controller.

Rescator · « **Reply #2030 on:** May 08, 2016, 02:15:04 pm »

Hello,

@SirKnowsAlot
I think I have the same tester.
I do not know which version of firmware. The splashscreen does not indicate the version number. (view the photo)
The operation is about right, except for the test with J-FET (tested: 2N3819 and MPF 102)

I think the only solution is to change the firmware, but I do not know which to choose.
I read in detail www.mikrocontroller.net about the transistortester, but it's not clear to me

I think I'll just change tester model !

SirKnowsALot · « **Reply #2031 on:** May 08, 2016, 09:58:11 pm »

Yes that is my exact tester.
I'm afraid that my interest in this tester has just disappeared--I was attempting to reflash and Windows' command line retrieval screwed me over. I think my efuse data was scrambled and now my tester will not respond to avrdude.
This was the tail-end of the command that was sent:

Code: [Select]

... -U lfuse:w:0x04:m -U hfuse:w:0xD9:m -U efuse:w:0x04:mD9:m -U efuse:w:0x04:m

avrdude responded with:

Code: [Select]

avrdude: reading input file "0x04:mD9"
avrdude: invalid byte value (0x04:mD9) specified for immediate mode
avrdude: write to file '0x04:mD9' failed
avrdude: safemode: Fuses OK

I think that the first efuse parameter must have ruined my AVR. I was using the command retrieval in order to eliminate entering the long command string and didn't notice the corrupted parameter.

I hoped that I could just go back and reprogram the fuses, but the device will not respond to avrdude at all. Even with -F option.

Macbeth · « **Reply #2032 on:** May 09, 2016, 01:05:18 am »

What on earth is "mD9" ? I suggest you double check your command line...

e.g.

... -U lfuse:w:0x04:m -U hfuse:w:0xD9:m ~~-U efuse:w:0x04:mD9:m~~ -U efuse:w:0x04:m

onlooker · « **Reply #2033 on:** May 09, 2016, 01:08:15 am »

Fuse messing up happened to me too. I just bought a new atmega328p (about $1) to replace it. To prepare for more mess ups, one can also buy an AVR high voltage parallel programmer that can reprogram/correct fuses for about $17.

kenabi · « **Reply #2034 on:** May 09, 2016, 03:48:10 am »

on my fish8840 (the one with the case) whats the pin that outputs the contrast signal? trying to track this down from the lcd in isn't working, as frankly nothing seems to do anything beyond shutting the thing off when i try to apply a pot between any pins and ground. if i can figure out which one is actually the contrast pin from the avr and trace outwards maybe i can get somewhere.

madires · « **Reply #2035 on:** May 09, 2016, 09:49:51 am »

The contrast of a graphic LCD is set by a command usually, and not via a dedicated pin like V0 for HD44780 compatible displays. k and m-firmware allow to change the contrast for graphic LCDs via the main menu.

SirKnowsALot · « **Reply #2036 on:** May 09, 2016, 11:44:43 am »

Quote from: Macbeth on May 09, 2016, 01:05:18 am

What on earth is "mD9" ? I suggest you double check your command line...

As I indicated in my post, I was using the command-line retrieval in the DOS box and it added the extra characters. Because I wasn't paying close attention to what I was doing, I sent the command without correcting it.

The moral here is to be very careful when programming your AVR.

richfiles · « **Reply #2037 on:** May 15, 2016, 03:29:55 am »

You know, a fun component to measure is a piezo disc (it'll show up as a capacitor). You get to listen in on the test!

Just got my tester yesterday. It's marked as an EZM328 V1.10. It has a really good looking graphic LCD, an encoder, SMT pads, and sockets for both tester and function gen. The best part is the through hole construction and socketed micro controller. Feels very hackable! Construction quality feels VERY good too! Only one little spot of flux was missed. the rest of the board is perfectly clean, and I see no bad solder joints.

at2marty · « **Reply #2038 on:** May 15, 2016, 03:51:59 pm »

I bought one of these and put it together yesterday. The firmware that shipped with it was shown as Version 1.12k. However, I wanted to customize the firmware so I downloaded the latest release of the software, changed a couple of options in the Makefile in the Software/trunk/mega328_st7565_kit directory, compiled and uploaded to a spare Mega 328p that I had. After spending some time playing with it, so far I'm impressed. For just under $20 it seems to be a handy little device.

The following is the system that I used to build the firmware.

Linux Operating System
avr-gcc 4.8.1
avrdude 6.1

I programmed it using an stk500 programmer, though there are less expensive options available.

morbid80 · « **Reply #2039 on:** May 19, 2016, 07:12:37 am »

great news for those who have the new version Chinese LCR-T3/T4 ( slightly different board with 2 extra contact holes on the front) like mine. i found a useful tips from a buyer (1FebSA) on banggood product review, suggesting to use mega328_st7565_kit firmware instead, and modify CFLAGS += -DLCD_ST7565_V_FLIP=0 (value 1 -> 0) in the makefile.
voila, my tester is now running on latest K firmware 1.12k.

attached is the transistortester HEX and EEP file. i suggest to set manually your contrast value after flashing. mine was set to 105.

Gyro · « **Reply #2040 on:** May 19, 2016, 09:38:05 am »

Those holes look as if they're for substituting a through-hole crystal.

morbid80 · « **Reply #2041 on:** May 19, 2016, 12:13:01 pm »

managed to flash a working M firmware 1.22m too, by using ST7565R, SPI LCD interface setting in the config.h file( need to uncomment #define LCD_FLIP_Y , and lcd _contrast set to 14 ).
however the display seems a little bit off, maybe the font size is big.
i keep getting 'battery? 3: 4mV' message during probing. can i know what is the cause?

madires · « **Reply #2042 on:** May 19, 2016, 01:02:53 pm »

The problem with the display offset can be fixed by en/dis-abling LCD_OFFSET_X. 'battery? 3: 4mV' means, that the tester measured 4mV at probe pin #3 without any voltage applied. Please run the self-adjustment (see the readme for the procedure) and if that doesn't help increase CAP_DISCHARGED from 2 to 4.

Rescator · « **Reply #2043 on:** May 19, 2016, 06:35:29 pm »

Hello,

@morbid80

Thank you so much for sharing the solution.
It works fine on my tester identical to yours.

I tried to change several settings of the Makefile, without success. Now it's OK

Thanks again

caius · « **Reply #2044 on:** May 19, 2016, 10:55:11 pm »

Hi all,
in your opinion which is the best DIY kit available at the moment?I thinking about this to replace my old M128 tester:

http://www.ebay.com/itm/321944016234

johnka · « **Reply #2045 on:** May 30, 2016, 11:37:51 am »

I got the GM328A v1.20 2015.05 from ebay. It came with 1.12k firmware. I removed the push button and install a rotary encoder like on this post from @firepower.
I tried to reflash it with a USBasp by editing the Makefile on mega328_GM328 folder. After powering it up there is something like scrolling text on the screen and it shuts down after 3 sec even with a component attached on probes. I even tried to flash with the default TransistorTester.hex there was in mega328_GM328 folder without any luck.
What should I do to fix it? Has anyone kept the original firmware of the GM328? What should I change in the Makefile?

madires · « **Reply #2046 on:** May 30, 2016, 12:05:19 pm »

Anything about a low battery voltage? In that case, and if the battery is ok, you might have to check the voltage divider for measuring the battery voltage. Some clones use non-standard values for the resistors, but that can be adjusted in the source code.

johnka · « **Reply #2047 on:** May 30, 2016, 12:58:40 pm »

Yes the voltage divider was wrong but it was not causing th problem. The resistors on the voltage divider on my board are 33K and 2.2K so I changed the voltage divider option to:
CFLAGS += -DBAT_NUMERATOR=352
CFLAGS += -DBAT_DENOMINATOR=22
edit: That was causing fasle battery reading at start (it was reading 34V so I changed them back to 133 and 33)

The problem is present even without the battery connected (when I have the USBasp connected in the ISP header pins.

edit: I had forget a -U parameter while flashing and the eeprom data were not loaded. After that it got fixed. The rotary encoder seems to work fine. Now I have to calibrate it.

hansibull · « **Reply #2048 on:** May 30, 2016, 09:23:55 pm »

Does anyone have any experience with the transistor tester with a color LCD? It's using the latest version (1.22), and got a built in IR receiver for protocol decoding. A picture from AliExpress indicates it can measure zener breakdown voltages above 4.7v as well!

I haven't found any pics of the circuit board, and not a single review either.. Here's the Ebay link: http://www.ebay.com/itm/121959157850

Why should/shouldn't I buy this tester? Are there any better ones on the market that comes in a case as well?

timofonic · « **Reply #2049 on:** May 30, 2016, 11:12:38 pm »

Quote from: hansibull on May 30, 2016, 09:23:55 pm

Does anyone have any experience with the transistor tester with a color LCD? It's using the latest version (1.22), and got a built in IR receiver for protocol decoding. A picture from AliExpress indicates it can measure zener breakdown voltages above 4.7v as well!

I haven't found any pics of the circuit board, and not a single review either.. Here's the Ebay link: http://www.ebay.com/itm/121959157850

Why should/shouldn't I buy this tester? Are there any better ones on the market that comes in a case as well?

Color? What?


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Author Topic: $20 LCR ESR Transistor checker project (Read 3452942 times)

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