$20 LCR ESR Transistor checker project

[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

[indman]

Did I buy the wrong screen or something?

Yes, this display is working, but it is different from the one that was damaged.

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

You need to connect the backlight LED to avoid this effect

[dazz]

Did I buy the wrong screen or something?

Yes, this display is working, but it is different from the one that was damaged.

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

You need to connect the backlight LED to avoid this effect

OK, thanks again. I think I'm going to get me a new meter and be done with it. Damn it...

[dazz]

OK, I've decided to try and flash a modified version of the firmware to fix the orientation of the text, then I'll run wires from the pcb to the flex cable and fix that in place with hot glue.

Is this the part of the code in lcd-routines.c that needs tweaking to mirror the display?

Code: [Select]

volume = eeprom_read_byte(&EE_Volume_Value); // read Vop
   lcd_command(CMD_SET_VOP_UPPER | ((volume >> 5) & 0x07)); // set upper Vop
   lcd_command(CMD_SET_VOP_LOWER | (volume & 0x1f)); // set lower Vop
   lcd_command(CMD_SET_START_LINE | (LCD_ST7565_Y_START & 0x3f));       // Set the Start line 0
   lcd_command(CMD_SET_ALLPTS_NORMAL); // 0xa4 set display to normal
   lcd_command(CMD_SET_POWER_CONTROL | 4); // 0x28|4 Charge Pump ON
   lcd_command(CMD_SET_COM_REVERSE); // 0xc8
   lcd_command(CMD_SET_COM_NORMAL); // 0xc0 set normal Y orientation
   lcd_command(0xa1); // set MX, X orientation, is pad selectet!
   lcd_command(0xaa); // set horizontal mode
   lcd_command(0xac); // set initial row
   lcd_command(0x08); // initial row = 8  (0-7)
   lcd_clear();
   lcd_command(CMD_DISPLAY_ON); // 0xaf Display on
   lcd_set_cursor(0,0);

[dazz]

I already have WinAVR installed, and it seems to compile the code and generate the hex and eep files just fine. I guess I just need to figure out how to mirror the screen, and I also need to flip the screen 180º. Or I think so.

Using this repo for the source, not sure if that's the right one. Any pointers are appreciated.

[elecdonia]

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

This same type of thing has happened to me: Although frustrating and time consuming, I prefer to think of these events as “learning experiences.” One new habit I’ve developed is to take plenty of photos before and during the disassembly process.
Also not every LCD screen of similar dimensions and specs has its flex cable oriented the same way. I’ve run into this myself.

[indman]

OK, I've decided to try and flash a modified version of the firmware to fix the orientation of the text, then I'll run wires from the pcb to the flex cable and fix that in place with hot glue.
Is this the part of the code in lcd-routines.c that needs tweaking to mirror the display?

No, you don't need to delve so deeply into the code to correct the orientation of the image.
All the necessary settings that you need to configure are in the Makefile file from the folder "mega328_T4_v2_st7565":

# If LCD_ST7565 option is set to 1: Flip the display's horizontal direction.
#CFLAGS += -DLCD_ST7565_H_FLIP=1
# With LCD_ST7565_H_OFFSET you can specify a horizontal pixel offset to the display window.
# The controller knows 132 horizontal pixel, the window shows only 128 pixel.
# OFFSET values can vary for the connected display type to 0, 2 or 4.
CFLAGS += -DLCD_ST7565_H_OFFSET=0
# If LCD_ST7565 option is set to 1: Flip the display's vertical direction
#CFLAGS += -DLCD_ST7565_V_FLIP=1

[dazz]

This same type of thing has happened to me: Although frustrating and time consuming, I prefer to think of these events as “learning experiences.” One new habit I’ve developed is to take plenty of photos before and during the disassembly process.
Also not every LCD screen of similar dimensions and specs has its flex cable oriented the same way. I’ve run into this myself.

You're 100% right. I'll be more disciplined from now on.

No, you don't need to delve so deeply into the code to correct the orientation of the image.
All the necessary settings that you need to configure are in the Makefile file from the folder "mega328_T4_v2_st7565":

# If LCD_ST7565 option is set to 1: Flip the display's horizontal direction.
#CFLAGS += -DLCD_ST7565_H_FLIP=1
# With LCD_ST7565_H_OFFSET you can specify a horizontal pixel offset to the display window.
# The controller knows 132 horizontal pixel, the window shows only 128 pixel.
# OFFSET values can vary for the connected display type to 0, 2 or 4.
CFLAGS += -DLCD_ST7565_H_OFFSET=0
# If LCD_ST7565 option is set to 1: Flip the display's vertical direction
#CFLAGS += -DLCD_ST7565_V_FLIP=1

Awesome! Thanks, I'll try that. Technically I just need to flip the display horizontally. The screen will be upside down, but I can always flip the whole device and use it that way, not a huge deal.

[MrSqueaky]

I received an LCR-TC2 from Aliexpress that I ordered in December 2022. The board appears to be updated. The boot screen says firmware is 3.1E and chip U3 seems to have been removed. No options for changing the power off delay (which is annoying short).

I previously had a round GM328A but the display driver was glitchy and wouldn't initialise properly half of the time. I managed to smash the display and couldn't easily source a replacement (I think it is a Samsung E1310/E1360/E1360M/B210/B220/B510 copy)

[dazz]

OK, I've decided to try and flash a modified version of the firmware to fix the orientation of the text, then I'll run wires from the pcb to the flex cable and fix that in place with hot glue.
Is this the part of the code in lcd-routines.c that needs tweaking to mirror the display?

No, you don't need to delve so deeply into the code to correct the orientation of the image.
All the necessary settings that you need to configure are in the Makefile file from the folder "mega328_T4_v2_st7565":

# If LCD_ST7565 option is set to 1: Flip the display's horizontal direction.
#CFLAGS += -DLCD_ST7565_H_FLIP=1
# With LCD_ST7565_H_OFFSET you can specify a horizontal pixel offset to the display window.
# The controller knows 132 horizontal pixel, the window shows only 128 pixel.
# OFFSET values can vary for the connected display type to 0, 2 or 4.
CFLAGS += -DLCD_ST7565_H_OFFSET=0
# If LCD_ST7565 option is set to 1: Flip the display's vertical direction
#CFLAGS += -DLCD_ST7565_V_FLIP=1

One more question, please. Is this the right repo? https://github.com/Mikrocontroller-net/transistortester
There hasn't been a commit there in one year

[indman]

https://github.com/Mikrocontroller-net/transistortester/tree/master/Software/trunk
Here is the current actual k-firmware distribution 07.10.2021

[dazz]

https://github.com/Mikrocontroller-net/transistortester/tree/master/Software/trunk
Here is the current actual k-firmware distribution 07.10.2021

Great, thanks. That's the one I was using 

[dazz]

Success! Thanks everyone for the help