$20 LCR ESR Transistor checker project

[stj]

"you dont know what your talking about." 
Yes I do. But that's one of us....

"the kit IS a real colour lcd."
I thought that #2 was a monochrome LCD with a dark background and yellow text.

There are others I see with just the green or blue backlit screen with boring black text.
Hence the confusion.
So I ask will the #2 unit be able to display as the #1 unit in multiple colors and the same format? And can the #1 photo be adapted to include the rotary encoder, or is that software prohibitive?

the reason the colour kit is just 2 colours (foreground and background) is because the software is designed for a monochrome display.

whoever designed that cased unit tomtop sells has gone to a LOT of trouble with the firmware.
as for adding a rotary encoder, i'm not sure there is much point - i suspect they have left a lot of features out to save memory for the coloured display code.
it uses a different cpu too - atmega324pa
foto's
https://yadi.sk/d/yW8xa5NJgUo5z/??-1/Photo


i can tell you from experience with the kit that i cant enable every feature without running out of flash!

[mpavlov]

This version (GM328x ESR tester (SVN684) - v2(1).zip) of firmware does not works with my kit. I found GM328_EZM_v1.12k_r541.zip from https://www.mikrocontroller.net/topic/345717 works but does not support the rotary encoder.

[stj]

this one works - if you cant make it work then your programming it wrong.

[vinceroger]

this one works - if you cant make it work then your programming it wrong.

http://www.ebay.com/itm/331873741389?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
I have just updated my tester to this version 16mhz and all does work fine inc rotary encoder
I used 3 seperate commands
avrdude -c USBasp -p m328p -U flash:w:TransistorTester.hex

avrdude -c USBasp -p m328p -U eeprom:w:TransistorTester.eep

avrdude -c USBasp -p m328p -U lfuse:w:0xf7:m \-U hfuse:w:0xd9:m \-U efuse:w:0xfc:m

[alte]

Please, I need help.

I have put together this kit from http://www.aliexpress.com/item/2016-DIY-kits-TFT-LCD-M328-Transistor-Tester-LCR-Diode-Capacitance-ESR-voltage-meter-PWM-Square/32649811953.html?spm=2114.13010608.0.93.OBbTox  I had to solder the three protection smd parts myself.  Kit does not include test capacitor.

With 9v batt plugged in DC jack and encoder pressed down, there is 235mA draw from batt.  The T3 labeled 9012 gets hot  .  0 volts on socket pin 7.  In circuit the 9012 and two 9014 transistors test good.  The 5v reg 7550A-1 shows shows some voltage drops on every pin in both ways.

I have dis-soldered the LED and surge suppressor but no help.

Any ideas?

Update:

Thanks to stj for pointing it out, I soldered the SRV05-05 front to back.  Once removed device worked!

I have this same kit, which came with the SMD components pre-soldered , so it was pretty simple to assemble.
But it does not work    when I press the encoder button (long or short) the LED flashes briefly and the display backlight flickers, but that's all..
Power is present where you'd expect it, so the regulator works.
So I was thinking maybe the display is defective and I wanted to hook it up to an arduino to test.
I figured it must have a ST7735 driver, but I cannot get the pinout correct, it does not match the only ST7735 from config_328.h.
Does anyone know the pinout of the display ? The schematic matches what I measured, but what function is where..
AT328 pin                  disp.pin
PD0      2   LCD_?      2
PD1      3   LCD_?      3
PD2      4   LCD_?      5
PD3      5   LCD_?      4
PD5      11   LCD_?      6

[vinceroger]

Please, I need help.

I have put together this kit from http://www.aliexpress.com/item/2016-DIY-kits-TFT-LCD-M328-Transistor-Tester-LCR-Diode-Capacitance-ESR-voltage-meter-PWM-Square/32649811953.html?spm=2114.13010608.0.93.OBbTox  I had to solder the three protection smd parts myself.  Kit does not include test capacitor.

With 9v batt plugged in DC jack and encoder pressed down, there is 235mA draw from batt.  The T3 labeled 9012 gets hot  .  0 volts on socket pin 7.  In circuit the 9012 and two 9014 transistors test good.  The 5v reg 7550A-1 shows shows some voltage drops on every pin in both ways.

I have dis-soldered the LED and surge suppressor but no help.

Any ideas?

Update:

Thanks to stj for pointing it out, I soldered the SRV05-05 front to back.  Once removed device worked!

I have this same kit, which came with the SMD components pre-soldered , so it was pretty simple to assemble.
But it does not work    when I press the encoder button (long or short) the LED flashes briefly and the display backlight flickers, but that's all..
Power is present where you'd expect it, so the regulator works.
So I was thinking maybe the display is defective and I wanted to hook it up to an arduino to test.
I figured it must have a ST7735 driver, but I cannot get the pinout correct, it does not match the only ST7735 from config_328.h.
Does anyone know the pinout of the display ? The schematic matches what I measured, but what function is where..
AT328 pin                  disp.pin
PD0      2   LCD_?      2
PD1      3   LCD_?      3
PD2      4   LCD_?      5
PD3      5   LCD_?      4
PD5      11   LCD_?      6

some of these testers are shipped out with no firmware on the atmega ic i myself have had this issue once new firmware installed on the ic all was fine,

[alte]

Thanks, I could give that a try. I see a lot of firmware's in this thread , do you know which one I'd need for this specific tester ?

[vinceroger]

im not sure of the exact firmware needed sorry im sure someone will advise one to try shortly

[flywheelz]

Thanks, I could give that a try. I see a lot of firmware's in this thread , do you know which one I'd need for this specific tester ?

On page 93 post 2322 by stj has latest. Try the AY-AT

[alte]

Thanks, I could give that a try. I see a lot of firmware's in this thread , do you know which one I'd need for this specific tester ?

On page 93 post 2322 by stj has latest. Try the AY-AT

Thanks, that seems to be the right one, I have some pictures and AY-AT is printed on het board.
I'm going to give it a try.

[stj]

AY-AT colour tft kit firmware.

[mpavlov]

Hi vinceroger, stj,

Thank you for detail information, obvious I am doing something wrong when programming the chip with TL866.

[vinceroger]

Hi vinceroger, stj,

Thank you for detail information, obvious I am doing something wrong when programming the chip with TL866.

I have this progrmmer myself try this (a member on this forum helped me with these instructions)
This is the picture with the correct settings for the programmer.
https://www.dropbox.com/s/zqacxby4ayngy2c/Fuses%20on%20TL866A.jpg?dl=0

The only thing you need to do is to load the TransistorTester.hex in the "Code Memory" and the TransistorTester.eep in the "Data Memory"
Pay attention and use always "INTEL HEX" as File Format when you load the files. By default the TransistorTester.eep will be recognized as Binary and you have to change it during loading.

[mpavlov]

Hi vinceroger,

Thank you very much finally the tester works!   

The problems was that I had programmed the  TransistorTester.eep like binary not hex.

[vinceroger]

Hi vinceroger,

Thank you very much finally the tester works!   

The problems was that I had programmed the  TransistorTester.eep like binary not hex.

Glad you have your tester working and yes i made that mistake too when i first used my programer.

[kapuchy]

My version works fine (transistors, capacitors, resistors) but results for small inductors are sometimes weird, for example 128 Mohm or 18 pF instead of 25 uH. There are photos attached. I do not know what is going on. Adjustment procedure: done and save. Shoud I use another power supply, firmware or better linear regulator? Sometimes it helps when I touch GND during "probing" appears.

Firmware version: Markus 1.24m trendy,
Microcontroller: Atmega 328P @ 16 Mhz crystal,
AREF capacitor = 1 nF,
2,5 VDC voltage "reference" = L1117-25C (I know should be LT1004)
Power supply: 12 VDC switched mode + 7805 linear regulator.

[madires]

Yes, SMPSUs or DC/DC converters can cause strange results. Please try a linear power supply or an additional LC filter. One issue I've seen so far, is that a cap around 50µF is detected, despite no component is connected, while the tester is powered via a buck converter.

[hapless]

My version works fine (transistors, capacitors, resistors) but results for small inductors are sometimes weird, for example 128 Mohm or 18 pF instead of 25 uH. There are photos attached. I do not know what is going on. Adjustment procedure: done and save. Shoud I use another power supply, firmware or better linear regulator? Sometimes it helps when I touch GND during "probing" appears.

Firmware version: Markus 1.24m trendy,
Microcontroller: Atmega 328P @ 16 Mhz crystal,
AREF capacitor = 1 nF,
2,5 VDC voltage "reference" = L1117-25C (I know should be LT1004)
Power supply: 12 VDC switched mode + 7805 linear regulator.

Holy cow, all those wires...  In addition to what was said above, I would say that if you have any flux residue on the board, try to clean it off completely. That could help with the large resistance problem. Also, anchor down the wires that are anywhere near the probes. Their capacitance and inductance may be changing while measurement is in progress, thus making the tester think that it's looking at something other than what's really there. Lastly, a nice case might be able to isolate the probing conductors from the environment.

[alte]

Thanks, I could give that a try. I see a lot of firmware's in this thread , do you know which one I'd need for this specific tester ?

On page 93 post 2322 by stj has latest. Try the AY-AT

I had a bit of trouble to get avrdude to work, needed to hook up a crystal to be able to communicate with the 328. Once I could communicate I found the fuses for external crystal were indeed set, but flash was empty and there was some data in the eeprom.. Very strange, don't know what happened with that chip.
Then I could write the flash/eeprom/fuses and it verified ok. 
It did make a difference; only the backlight lit up and nothing else happened   Then I found that there was only power to the chip and display while the button was pressed.
Turned out I swapped the 3k3 and 33k R7/R10 voltage divider resistors in the power circuit 
After fixing that (man it's difficult to desolder parts from a double sided PCB..) it's WORKING
Thanks for your support guys !

[flywheelz]

Thanks, I could give that a try. I see a lot of firmware's in this thread , do you know which one I'd need for this specific tester ?

On page 93 post 2322 by stj has latest. Try the AY-AT

I had a bit of trouble to get avrdude to work, needed to hook up a crystal to be able to communicate with the 328. Once I could communicate I found the fuses for external crystal were indeed set, but flash was empty and there was some data in the eeprom.. Very strange, don't know what happened with that chip.
Then I could write the flash/eeprom/fuses and it verified ok. 
It did make a difference; only the backlight lit up and nothing else happened   Then I found that there was only power to the chip and display while the button was pressed.
Turned out I swapped the 3k3 and 33k R7/R10 voltage divider resistors in the power circuit 
After fixing that (man it's difficult to desolder parts from a double sided PCB..) it's WORKING
Thanks for your support guys !

I am glad you got it to work!  Yes I found the same thing about the double sided pcb, a real pain to desolder.  I ripped out a leg from LED trying to remove it.  When I put my AY-AT kit together, I put SRV05-04/MC5 front to back shorting VCC to GND

Yesterday, I was able to use avrdude with ArduinoISP wired directly to tester to flash SVN684 successfully.  I didn't use extra XTAL. 

Only thing I am missing is extra frequencies in f-gen.  Original firmware had 1mhz, 2mhz, and others...

[stj]

Original firmware had 1mhz, 2mhz, and others...

if that's true then the original firmware must be seriously ancient.

the current official firmware has a variable oscillator, but it's very hard to use.
so my firmware has the older set-frequency code in it instead.
but i changed the available frequency's to usefull ones.

btw, i did put up a thread for several weeks asking people what frequency's would be usefull - not one reply!!
so i put the 50 & 60 Hz mains timebases and rectified derivatives in, together with a couple of tuning frequency's used by musicians.

[bitseeker]

btw, i did put up a thread for several weeks asking people what frequency's would be usefull - not one reply!!

Was that a post in here or a separate thread?

so i put the 50 & 60 Hz mains timebases and rectified derivatives in, together with a couple of tuning frequency's used by musicians.

Those sound good.

[stj]

it was a seperate thread on a different forum.

the 50/60/100/120Hz is very usefull, because you can test stuff that normally gets timing pulses from a mains transformer.

[bitseeker]

it was a seperate thread on a different forum.

Ah, OK. That's why it didn't sound familiar.

the 50/60/100/120Hz is very usefull, because you can test stuff that normally gets timing pulses from a mains transformer.

Absolutely. There's also 400 Hz for some power systems (military?). Round numbers such as 1, 10, 100 kHz. I don't recall what the low end of the generator's range is, but there's 1 Hz for clock projects.

The U1252B I have uses the following presets for its frequency gen:

0.5, 1, 2, 5, 10, 15, 20, 25, 30, 40, 50, 60, 75, 80, 100, 120, 150, 200, 240, 300, 400, 480, 600, 800, 1200, 1600, 2400, 4800 Hz

It doesn't go very high, but it's interesting to see what they chose. I'm not sure why 1 kHz wasn't included.

[stj]

400Hz is 3phase, i'v never seen it used by any circuits though.

1Hz i wouldnt do.
the frequency's arent exact, they are divisions of the master clock.
and that's not exact either buy default.
although i'v seen testers with one or both of the 22pF crystal caps replaced by trimmers so the crystal could be tuned.