$20 LCR ESR Transistor checker project

[Calambres]

Anyone know of a source to buy a legit Atmel tester in the form of a T1, T2, T7... I like the convenience of the package but have never found one that's not fake, and I've opened quite a few!

[xfint34]

What about the GM328A DIP version with the acrylic case?

[Calambres]

Well, my request was:

Anyone know of a source to buy a legit Atmel tester in the form of a T1, T2, T7... I like the convenience of the package...

The GM328A DIP version with the acrylic case is not what i'm looking for...

[luciano]

Hello, what are the problems if I have a tester with a fake (or not Atmega) CPU ? Do they work not good ? Or there is no bad effect ?

[madires]

You can't program an OSHW firmware and some measurements are subpar.

Edit: Some also lack the self-adjustment.

[Fuzzy Star]

Hello, what are the problems if I have a tester with a fake (or not Atmega) CPU ? Do they work not good ? Or there is no bad effect ?

https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4741682/#msg4741682

https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4762751/#msg4762751

[Aldo22]

Hello, what are the problems if I have a tester with a fake (or not Atmega) CPU ? Do they work not good ? Or there is no bad effect ?

I have a TC1 with the APT32F172K8T6 and it works quite OK for most components.
Here I had made some tests.
You can find it 2 posts below this link target (Reply #8323):

For some reason the actual link target is not working.

[Aldo22]

Aldo22 Because you misspelled the post number in your link. It should look like this 
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4765046/#msg4765046

I intentionally took another target because the direct link (yours too) just doesn't work (at least not for me).

[indman]

Yes, that's right, there was some kind of glitch in the messaging system. I've noticed this before.

[mentholflash]

Hi all
I have one of the original clones ver 2.2 2012/11/26 atmega128 the same as pic 1 but i have the 2 caps between the lcd headers and a 8m crystal like a mashup of the 2 pics
I am looking to upgrade as much as possible
I have installed an atmega328(duino lilypad) and bought a rotary encoder
I also want to check in circuit esr
Can anyone point me in the direction of upgrade steps with adding encoder and the best firmware to use and steps to be taken
Thanks look forward to your replies

[indman]

mentholflash, I have attached the firmware for your clone below. You will find the encoder connection and programming flash method in the complete manual from Karl-Heinz.

[mentholflash]

Thank you for your speedy responce
I did read the encoder part but pd1 and pd3 are not connected at my lcd is it best to just solder to the ic or is there a better way to solder connections.
Thanks again
ps also looking to get a different screen would you know which is best for this device and would it benefit me to put a 1200 crystal just cause i have 1
cheers

[indman]

I did read the encoder part but pd1 and pd3 are not connected at my lcd is it best to just solder to the ic or is there a better way to solder connections.

Solder to the ic.

ps also looking to get a different screen would you know which is best for this device and would it benefit me to put a 1200 crystal just cause i have 1.

You can connect to the device any display with a controller that is supported by the firmware authors, but you will also have to update the firmware for the new display. You can only put quartz from the 8,16,20 MHz range into a clone.
Other frequencies are not suitable! All this is explained in detail in the manual.

[mentholflash]

Thank you

[u666sa]

If anyone looking for clone on real atmel 324

https://aliexpress.ru/item/1005002448100326.html

 

[uboot]

Anyone know of a source to buy a legit Atmel tester in the form of a T1, T2, T7... I like the convenience of the package but have never found one that's not fake, and I've opened quite a few!

It seems that the Joy-IT LCR T7 (https://joy-it.net/de/products/JT-LCR-T7) always has a legit Atmega. It can be bought - in Germany at least - from different shops like Reichelt, ELV, Pollin, and Conrad. Some of them ship to other countries.

I just bought one and it has an Atmega324PA and usual ingredients like STC15L104W, TL431, LM7805, Boost Converter, IR Detector, but a slightly different PCB layout than what I have found elsewhere about the Joy-IT LCR T7, e.g. https://arnowelzel.de/m-tester




But I could not get OSHW firmware to work with it yet 

Following the instructions in the Clones document of v1.50m, I have updated the STC15 uC with https://github.com/atar-axis/tc1-u4 and set up the Makefile, config.h, and config_644.h but after flashing the device does not boot. (Lipo battery was disconnected of course during all ISP operations)

Now, when I press the test button, the LCD will power up with backlight and blank black screen and as soon as I release the button it switches back off. Nothing else will happen.

If you look at the pictures, C3 right above the Atmega is missing, but it was like that from the beginning and the device did work before with stock firmware, but I didn't like it - it even did not calculate ESR...


Any ideas for a noob like me on where to start with trouble shooting?

[indman]

Any ideas for a noob like me on where to start with trouble shooting?

Yes, there are ideas. You have a clone model from FNIRSI, and these guys could have changed the connection between the display and the controller. You also need to trace which controller ports the U8 pins are connected to?
Therefore, first you need to draw this schematic and compare it with the classic one for this clone. Your further actions will depend on this. Good luck.

[Obelix2007]

... @uboot, your board is very similar to the TC1 and T7, but J7 is missing.

In the appendix is the circuit of TC1/T7. This way you can better determine the port occupancy.

Good luck

Greetings Horst

[vklimk]

Didn't read the forum for a long time and have found different GCC comparision in accordance to fw size.
I have downloaded some gcc versions, including official one from microchip and have created a small script. Here is result for my particular case. So, sometimes the oldest one is the best one...

Code: [Select]

Trying system's avr-gcc [avr-gcc (GCC) 5.4.0] ... 28360 bytes
Trying avr-gcc-10.1.0-x64-linux [avr-gcc (GCC) 10.1.0] ... 30742 bytes
Trying avr-gcc-11.1.0-x64-linux [avr-gcc (GCC) 11.1.0] ... 30612 bytes
Trying avr-gcc-12.1.0-x64-linux [avr-gcc (GCC) 12.1.0] ... 31036 bytes
Trying avr-gcc-13.2.0-fc [avr-gcc (Fedora 13.2.0-1.fc38) 13.2.0] ... 28754 bytes
Trying avr-gcc-7.3.0-arduino [avr-gcc (GCC) 7.3.0] ... 28458 bytes
Trying avr-gcc-7.3.0-x64-linux [avr-gcc (GCC) 7.3.0] ... 28460 bytes
Trying avr-gcc-8.1.0-x64-linux [avr-gcc (GCC) 8.1.0] ... 28550 bytes
Trying avr-gcc-8.2.0-x64-linux [avr-gcc (GCC) 8.2.0] ... 28550 bytes
Trying avr-gcc-8.3.0-x64-linux [avr-gcc (GCC) 8.3.0] ... 28562 bytes
Trying avr-gcc-9.1.0-x64-linux [avr-gcc (GCC) 9.1.0] ... 30588 bytes
Trying avr-gcc-9.2.0-x64-linux [avr-gcc (GCC) 9.2.0] ... 30580 bytes
Trying avr8-gnu-toolchain-linux_x86_64-microchip [avr-gcc (AVR_8_bit_GNU_Toolchain_3.7.0_1796) 7.3.0] ... 28458 bytes

[uboot]

@vklimk how about compiler optimizations and switches? I wonder if latest avr-gcc can be tweaked to get same low sizes as past versions just because there are different defaults being used.

I guess you already you use -Os everywhere, right? But there is more.

Here is a nice article that you might translate with Google: https://www.mikrocontroller.net/articles/AVR-GCC-Codeoptimierung

For instance, -fno-jump-tables will reduce my current v1.50m build from 32072 to 32016 bytes.

And with a combination of CFLAGS += -ffunction-sections and LDFLAGS += -Wl,--gc-sections I was able to reduce that even further down to 31892 bytes.

[vklimk]

For instance, -fno-jump-tables will reduce my current v1.50m build from 32072 to 32016 bytes.

And with a combination of CFLAGS += -ffunction-sections and LDFLAGS += -Wl,--gc-sections I was able to reduce that even further down to 31892 bytes.

In my case it changes to the following if I add all these 3 options:

Code: [Select]

Trying system's avr-gcc [avr-gcc (GCC) 5.4.0] ... 28330 bytes
Trying avr-gcc-10.1.0-x64-linux [avr-gcc (GCC) 10.1.0] ... 30706 bytes
Trying avr-gcc-11.1.0-x64-linux [avr-gcc (GCC) 11.1.0] ... 30574 bytes
Trying avr-gcc-12.1.0-x64-linux [avr-gcc (GCC) 12.1.0] ... 30984 bytes
Trying avr-gcc-13.2.0-fc [avr-gcc (Fedora 13.2.0-1.fc38) 13.2.0] ... 28720 bytes
Trying avr-gcc-7.3.0-arduino [avr-gcc (GCC) 7.3.0] ... 28428 bytes
Trying avr-gcc-7.3.0-x64-linux [avr-gcc (GCC) 7.3.0] ... 28430 bytes
Trying avr-gcc-8.1.0-x64-linux [avr-gcc (GCC) 8.1.0] ... 28522 bytes
Trying avr-gcc-8.2.0-x64-linux [avr-gcc (GCC) 8.2.0] ... 28522 bytes
Trying avr-gcc-8.3.0-x64-linux [avr-gcc (GCC) 8.3.0] ... 28530 bytes
Trying avr-gcc-9.1.0-x64-linux [avr-gcc (GCC) 9.1.0] ... 30494 bytes
Trying avr-gcc-9.2.0-x64-linux [avr-gcc (GCC) 9.2.0] ... 30486 bytes
Trying avr8-gnu-toolchain-linux_x86_64-microchip [avr-gcc (AVR_8_bit_GNU_Toolchain_3.7.0_1796) 7.3.0] ... 28428 bytesAnd I have the same result if I don't use CFLAGS += -ffunction-sections and LDFLAGS += -Wl,--gc-sections.
gcc 5.4.0 produces the smallest fw again. In my specific case.

My options are the following at the moment:

Code: [Select]

# compiler flags
CC = avr-gcc
CPP = avr-g++
CFLAGS = -mmcu=${MCU} -Wall -I. -Ibitmaps
CFLAGS += -DF_CPU=${FREQ}000000UL
CFLAGS += -DOSC_STARTUP=${OSC_STARTUP}
CFLAGS += -gdwarf-2 -std=gnu99 -Os -mcall-prologues
CFLAGS += -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums
CFLAGS += -flto -fno-jump-tables
CFLAGS += -MD -MP -MT $(*F).o -MF dep/$(@F).d

# linker flags
LDFLAGS = -g -mmcu=${MCU} -Wl,--relax,-Map=${NAME}.map

PS. After reading that article you suggested I have added more options which allowed to save a little more space: -fno-inline-small-functions -fno-split-wide-types -fno-move-loop-invariants -fno-tree-loop-optimize -mstrict-X
And result is the following:

Code: [Select]

Trying system's avr-gcc [avr-gcc (GCC) 5.4.0] ... 28072 bytes
Trying avr-gcc-10.1.0-x64-linux [avr-gcc (GCC) 10.1.0] ... 30176 bytes
Trying avr-gcc-11.1.0-x64-linux [avr-gcc (GCC) 11.1.0] ... 30188 bytes
Trying avr-gcc-12.1.0-x64-linux [avr-gcc (GCC) 12.1.0] ... 30486 bytes
Trying avr-gcc-13.2.0-fc [avr-gcc (Fedora 13.2.0-1.fc38) 13.2.0] ... 28250 bytes
Trying avr-gcc-7.3.0-arduino [avr-gcc (GCC) 7.3.0] ... 28226 bytes
Trying avr-gcc-7.3.0-x64-linux [avr-gcc (GCC) 7.3.0] ... 28228 bytes
Trying avr-gcc-8.1.0-x64-linux [avr-gcc (GCC) 8.1.0] ... 28330 bytes
Trying avr-gcc-8.2.0-x64-linux [avr-gcc (GCC) 8.2.0] ... 28330 bytes
Trying avr-gcc-8.3.0-x64-linux [avr-gcc (GCC) 8.3.0] ... 28350 bytes
Trying avr-gcc-9.1.0-x64-linux [avr-gcc (GCC) 9.1.0] ... 30150 bytes
Trying avr-gcc-9.2.0-x64-linux [avr-gcc (GCC) 9.2.0] ... 30142 bytes
Trying avr8-gnu-toolchain-linux_x86_64-microchip [avr-gcc (AVR_8_bit_GNU_Toolchain_3.7.0_1796) 7.3.0] ... 28226 bytes
Options:

Code: [Select]

# compiler flags
CC = avr-gcc
CPP = avr-g++
CFLAGS = -mmcu=${MCU} -Wall -I. -Ibitmaps
CFLAGS += -DF_CPU=${FREQ}000000UL
CFLAGS += -DOSC_STARTUP=${OSC_STARTUP}
CFLAGS += -gdwarf-2 -std=gnu99 -Os -mcall-prologues -fno-inline-small-functions -fno-split-wide-types -fno-move-loop-invariants -fno-tree-loop-optimize -mstrict-X
CFLAGS += -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums
CFLAGS += -flto -fno-jump-tables
CFLAGS += -MD -MP -MT $(*F).o -MF dep/$(@F).d

# linker flags
LDFLAGS = -g -mmcu=${MCU} -Wl,--relax,-Map=${NAME}.map
avr-gcc 5.4.0 is the winner again.
And again - it is my particular code configuration. It may happen that for other code configuration another avr-gcc version will win.

[uboot]

@Obelix2007: compared to the schematics you posted, I found the following differences:

PB5 -> MOSI+LCD_SDA instead of MOSI+LCD_DC
PB6 -> only MISO instead of MISO+LDC_SDA
PB2 -> Collector of some 1AM NPN Transistor (MMBT3904LT1?) marked Q2 instead of NC
PB3 -> LCD_DC instead of NC

Connections to Test socket and STC15 look similar.

I then changed LCD pin assignment in the config file accordingly and reprogrammed it, but still same behavior.

So I suspect there is some difference in the power-up circuitry and I wonder if I will even need different firmware for the STC15 :-/


Emitter of Q2/1AM is grounded, Base is going to the Test button and when the latter is pressed, it's reaching out to R8+R30 on the very bottom left of the PCB. R30 goes to the Collector of another 1AM transistor (marked Q3) nearby, Emitter again grounded and Base going to C11+C5 wich go in parallel to GND.

R8 goes to what looks like Gate of an A1SHB/HM2301B  P-Channel Mosfet marked Q1 whose Drain is going to Pin4 of B628/U6 and U77.

Well, and the Test button has no direct connection to the STC15 

[indman]

uboot,As I suspected earlier, the Chinese guys from FNIRSI tried very hard to prevent you from easily updating the firmware to OSHW. Tell them a big thank you.

[Calambres]

I recently bought a TC2 HaoQi from AliExpress and the PCB was silkscreened with "T7-PLUS V2.0". The tester is utter crap as the measurements are very inconsistent, erroneous and all over the place 

[madires]

Well, and the Test button has no direct connection to the STC15 

Have you tried the settings for 'Multifunction Tester T7 with ATmega328' listed in the Clones file? Your tester looks very similar to that variant.