$20 LCR ESR Transistor checker project

[eti]

Amazon UK sourced LCR-T4 product info update:

https://www.amazon.co.uk/gp/product/B07J2Q4VY9/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Note: In the event this listing is edited or removed, I have archived the Amazon page in the current (incorrect listing) state, for your records: https://web.archive.org/web/20221231203216/https://www.amazon.co.uk/gp/product/B07J2Q4VY9/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

That archived URL seems to fail ONLY when clicked here, so I added it to a "tinyurl.com" URL:
https://tinyurl.com/amaz-B07J2Q4VY9-listing

This item arrived with the telltale signs of it being a Chinese counterfeited IC:

# No crystal
# USB-C socket
# CH-340N IC

Suffice to say I immediately went on CS chat, sent them these photos (attached and on the post immediately following this one) and they refunded without question, and allowed me to keep this product.

[eti]

Amazon UK sourced LCR-T4 product info update:

https://www.amazon.co.uk/gp/product/B07J2Q4VY9/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

This item arrived with the telltale signs of it being a Chinese counterfeited IC:

# No crystal
# USB-C socket
# CH-340N IC

Suffice to say I immediately went on CS chat, sent them these photos (attached and on the post immediately following this one) and they refunded without question, and allowed me to keep this product.

Second photo (front) attached:

[indman]

This item arrived with the telltale signs of it being a Chinese counterfeited IC:

It's a lottery. Even when the images show a genuine ATmega it doesn't mean that you'll get one with your new tester.

Madires spelled it right.Unfortunately, you could not win this lottery, like many others who want to get an authentic product from Chinese comrades.

[eti]

This item arrived with the telltale signs of it being a Chinese counterfeited IC:

It's a lottery. Even when the images show a genuine ATmega it doesn't mean that you'll get one with your new tester.

Madires spelled it right.Unfortunately, you could not win this lottery, like many others who want to get an authentic product from Chinese comrades.

Due to the sheer size of this thread and the variety of opinions, sketchy sometimes, elsewhere online and here, would you please clarify:

# What is “wrong” with the LCR-T4 units with no crystal, a counterfeit “mega328p” and a USB-C socket

# What firmware they’re running

# Whether there is a way to mod them and flash in a special version of the original project  firmware

?

Thank you. As much detail as possible please. Happy 2023! Blessings.

[indman]

"# What is “wrong” with the LCR-T4 units with no crystal, a counterfeit “mega328p” and a USB-C socket"

eti,the answers to your questions are on this page in a message from elecdonia
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4610050/#msg4610050
and my message below, in which I listed the detected flaws of these clones with fake chips
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4610314/#msg4610314

"# What firmware they’re running"
This is a proprietary firmware from the clone manufacturer.

"# Whether there is a way to mod them and flash in a special version of the original project  firmware"
There is no such possibility yet!

[eti]

"# What is “wrong” with the LCR-T4 units with no crystal, a counterfeit “mega328p” and a USB-C socket"

eti,the answers to your questions are on this page in a message from elecdonia
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4610050/#msg4610050
and my message below, in which I listed the detected flaws of these clones with fake chips
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4610314/#msg4610314

"# What firmware they’re running"
This is a proprietary firmware from the clone manufacturer.

"# Whether there is a way to mod them and flash in a special version of the original project  firmware"
There is no such possibility yet!

I appreciate your rapid help. Okay so it’s as good as useless, got it. I’ll keep it in my “might use one day” pile. 😁

[madires]

# What firmware they’re running

# Whether there is a way to mod them and flash in a special version of the original project  firmware

They use a modified k-firmware with a more fancy UI, but had to remove features to free up flash memory for the fancy UI. At the moment Karl-Heinz and I have no plans to support any other MCU. We have to wait and see what will happen after chipageddon is over, i.e. if ATmegas will be inexpensive and easy to source again, or not. However, a user is working on a port of the m-firmware for the Logic Green MCU.

[py-bb]

I haven't yet checked for any output from the USB port.

For that I just connected a terminal program to the virtual COM port the CH340N creates on a PC. I don't know what the serial port speed is though. A scope connected to the header near U1 could work that out.

When I opened my T7 up it had like 1 IC. if there is a USB->UART in there it is integrated into the main IC - in which case all you'll see is USB traffic. You wont see the baud rate from this.

That said 9600 is a good guess - do you know anything it's supposed to respond to?

"screen /dev/ttyUSB0" tends to set the baud rate to 9600 but it will do lots of non-trivial stuff for you (TTYs are a big topic) and set it up for you, this tends to abstract things like \r expected for newlines, but if you are stuck I find "echo -n -e 'WHATEVER\r' > /dev/ttyUSB0" works quite well (This is a Bashism)

 

[eti]

# What firmware they’re running

# Whether there is a way to mod them and flash in a special version of the original project  firmware

They use a modified k-firmware with a more fancy UI, but had to remove features to free up flash memory for the fancy UI. At the moment Karl-Heinz and I have no plans to support any other MCU. We have to wait and see what will happen after chipageddon is over, i.e. if ATmegas will be inexpensive and easy to source again, or not. However, a user is working on a port of the m-firmware for the Logic Green MCU.

Thank you. Who is "a user" btw?

[Spongey]

When I opened my T7 up it had like 1 IC. if there is a USB->UART in there it is integrated into the main IC - in which case all you'll see is USB traffic. You wont see the baud rate from this.

That said 9600 is a good guess - do you know anything it's supposed to respond to?

Some of the fakes have a CH340N chip connected to the MCU which look like a UART from their pin description. The same pins go to a 6 pin header nearby: presumably for flashing the device. A scope on there should reveal the baud rate.

I've tried a range of speeds including 9600baud and got no consistent output and nothing like readable ASCII. Maybe it's just binary data in a proprietary format?

I've no idea what data should be sent on there: presumably only FNIRSI know. I was hoping it would output something like a version number or the value of whatever it was measuring and maybe some usable commands, nope.

[madires]

Thank you. Who is "a user" btw?

A member of this forum.

[elecdonia]

Amazon UK sourced LCR-T4 product info update:
This item arrived with the telltale signs of it being a Chinese counterfeited IC:
     # No crystal
     # USB-C socket
     # CH-340N IC
Suffice to say I immediately went on CS chat, sent them these photos (attached and on the post immediately following this one) and they refunded without question, and allowed me to keep this product.

The MCU (U1) in the photo of this LCR-T4 PC board is NOT the Atmel ATmega328P.
I received an LCR-TC1 a few weeks ago which contains an identically (mis)labeled MCU. Evidently someone in China created a totally fake Atmel label and is applying it to this other MCU chip: APT32F172K8T6. The only thing in common between the ATmega328P and the APT32F172K8T6 is they are both housed in 32-pin TQFP packages.
(Personally I find deliberate mislabeling of electronic components to be extremely annoying and insulting. It is bad enough when the original label has been removed with sandpaper )

[elecdonia]

JLCPCB lists the APT32F172K8T6 MCU in their catalog:
 
    https://jlcpcb.com/partdetail/Aptchip-APT32F172K8T6/C448572

They even offer a downloadable .pdf data sheet… but only in Chinese language. I don’t know much about JLCPCB, never ordered PC boards from them (yet). They do run a lot of banner ads here on EEVblog.

[ozkarah]

Hi guys,

I bought an ESR02PRO.
1- How can I check the current firmware it has now?
2- Which fw is the latest compatible for the upgrade?

thanks...

[madires]

Usually the testers display the firmware version after powering on. If not, someone has removed it on purpose. You can update to the lastest k (1.13k) or m-firmware (1.48m).

[elecdonia]

Hello
Got 2 LCR Testers today from AliXpress..  New LCR-T4 and LCR-T7 Color 
Both have new firmware version 3.12K 
Does anybody know where to find this firmware.. or is it a hoax..  mean Chinese Variants.. ?
tnx for info.  JP

Could I ask you to please post photos of the PC boards of these LCR-T4 and LCR-T7 units which you received in December?

     I wish to determine whether any Chinese suppliers still use Atmel ATmega324 MCU.
ATmega324 has 44 pins (11 pins on each side of TQFP package).
No other MCU used in Transistor Testers has 44 pins except Atmel ATmega644.
There is a DIY upgrade which replaces original ATmega324 with ATmega644. Official OSHW Transistor Tester firmware for ATmega644 is available. This link describes the upgrade:
     https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg3578117/#msg3578117

However, starting in 2022 the Chinese suppliers are also using two different non-Atmel MCU which have 32 pins (8 pins per side): One type is APT32F172K8T6. Other is LGT8F328P. Evidently most of the LCR-TC1, LCR-TC2, and LC-T7 units sold since July 2022 contain these. Unfortunately there is no official OSHW Transistor Tester firmware for these recently manufactured units with non-Atmel MCU. Their firmware cannot be upgraded. Also these units lack several popular Transistor Tester features which were omitted by the Chinese suppliers.

Summary:
     ATmega324 MCU: 44-pin TQFP package. Fully supported by official OSHW Transistor Tester software. DIY upgrade to ATmega644 or ATmega1284 is possible.

     Alternate Chinese MCU, APT32F172K8T6 or LGT8F328P: 32-pin TQFP package. Software cannot be upgraded. Not supported by the OSHW Transistor Tester project.

[Obelix2007]

Summary:
     ATmega324 MCU: 44-pin TQFP package. Fully supported by official OSHW Transistor Tester software. DIY upgrade to ATmega644 is possible.

     Alternate Chinese MCU, APT32F172K8T6 or LGT8F328P: 32-pin TQFP package. Software cannot be upgraded. Not supported by the OSHW Transistor Tester project.

... DIY upgrade to ATmega1284 is also possible:

[elecdonia]

Summary:
     ATmega324 MCU: 44-pin TQFP package. Fully supported by official OSHW Transistor Tester software. DIY upgrade to ATmega644 is possible.
     Alternate Chinese MCU, APT32F172K8T6 or LGT8F328P: 32-pin TQFP package. Software cannot be upgraded. Not supported by the OSHW Transistor Tester project.

... DIY upgrade to ATmega1284 is also possible:

Lovely upgrade there! I forgot to mention the mega1284. I shall edit my post to include it.

[dazz]

Hope you guys can help me fix my T-4. I managed to break the LCD screen, so I bought a replacement off of aliexpress, but it's not working. Is this the right way to solder it, please?
Also attached a pic showing what it does when I power it up.

[elecdonia]

Hope you guys can help me fix my T-4. I managed to break the LCD screen, so I bought a replacement off of aliexpress, but it's not working. Is this the right way to solder it, please? Also attached a pic showing what it does when I power it up.

Could you post photos of your old broken LCD screen for comparison?
Do the flat flex PC cables look exactly the same for both old and new screens?

[dazz]

Hope you guys can help me fix my T-4. I managed to break the LCD screen, so I bought a replacement off of aliexpress, but it's not working. Is this the right way to solder it, please? Also attached a pic showing what it does when I power it up.

Could you post photos of your old broken LCD screen for comparison?
Do the flat flex PC cables look exactly the same for both old and new screens?

Thanks. They look the same to me, have a look:

EDIT: I should say the pads in the pcb were intact, and the new screen looks good as well. It also seems to be properly aligned, since when I fold it in position, both lugs at the bottom of the screen line up with the holes in the pcb

EDIT2: Tried re-flashing the firmware, still the same gibberish onscreen

[indman]

They look the same to me, have a look:

And now take a close look and compare how the cable should be soldered on the same clone as yours.
You turned the cable over.

[dazz]

They look the same to me, have a look:

And now take a close look and compare how the cable should be soldered on the same clone as yours.
You turned the cable over.

WTF? I reversed the cable orientation (and I don't know how a would mount it that way) and it works, but the text is all flipped horizontally. What gives? Was the screen not properly assembled or something?
I'll try to get a picture, but I need extra hands for that

[indman]

What gives? Was the screen not properly assembled or something?

The most important thing is that you do not damage the display cable.If there is a picture on the display, but it is mirrored, all this can be fixed with another firmware.

[dazz]

What gives? Was the screen not properly assembled or something?

The most important thing is that you do not damage the display cable.If there is a picture on the display, but it is mirrored, all this can be fixed with another firmware.

That's just one issue. With the flex cable in that orientation, I can't fold it in place on top of the pcb, or it would end sitting bottom up.
Did I buy the wrong screen or something?
Here's a pic:

EDIT: Something else seems wonky. Now I need to keep the button pressed, or else the screen goes blank