$20 LCR ESR Transistor checker project

[TheBay]

Just compiled 1.12k from the latest SVN for MK-328 with 16Mhz and Crystal test if anyone wants me to attach it here please ask.

[madires]

Just a quick question, is it correct that it cycles through the tests rather than display it on the screen and then switch off, also I have to double press the Test button to enter the menu is this right?

The firmware has two operation modes. When you power the tester on with a short key press, it runs in continous mode and will power off after five misses. You can change CYCLE_MAX in config.h to change the number. With a long key press the tester runs in hold-mode, i.e. it stays on und requires you to press the button to continue. It's explained in the README. Yes, to enter the menu you create a short between all three probes or press the button twice. With a rotary encoder you also have the option to turn left for entering the menu.

[TheBay]

Just a quick question, is it correct that it cycles through the tests rather than display it on the screen and then switch off, also I have to double press the Test button to enter the menu is this right?

The firmware has two operations modes. When you power the tester on with a short key press, it runs in continous mode and will power off after five misses. You can change CYCLE_MAX in config.h to change the number. With a long key press the tester runs in hold-mode, i.e. it stays on und requires you to press the button to continue. It's explained in the README. Yes, to enter the menu you create a short between all three probes or press the button twice. With a rotary encoder you also have the option to turn left for entering the menu.

Thanks for the reply, yeah it's all working perfectly.
Just trying out the K firmware as well, having a bit of a mess around with it today 

[Pukker]

Hi, friends! For a tester of DIY Kit "AY-AT" it is necessary to change in config_328.h  line
#define LCD_RES PD4 on
#define LCD_RES PD0 
  According to the diagram of a tester the output 2 processors is connected to contact of RESET of the display.

I have a AY-AT kit and being a bit lazy installed this version: https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1016572/#msg1016572 and didn't work, only got a white screen.

After seeing your message I decided to compile my own with the suggested change and it now works fine! My display must be the same as your friend's!

Please can you post your compiled version. I have the same problem with the M Version.
I don't have experience with compiling.
Thanks.

[hapless]

Hi, friends! If it is interesting to you, then I on pages of the topic made comparing of the software from Karl-Heinz Kübbeler and
Markus Reschke. The forum is Russian-speaking, but I think that according to photos it will be clear without the translation. I hope that this information will help two dear authors of this project to improve operation of a tester. Once again big gratitude for huge work!
The topic contains only 3 pages, comparing of firmwares begins with the 2nd page (a post #703275). Link to the topic http://vrtp.ru/index.php?showtopic=26994&st=0

From those pages, it looks like the m firmware has gained some cyrillic support while I wasn't looking (and it also looks like at least one of the fonts has the two halves of the resistor symbol interchanged)... interesting. 

[madires]

I'd add the cyrillic font and texts in the firmware, if someone would send me the files. Several users already asked for cyrillic support.

[hapless]

If you do that, I feel I should mention that for complete support it might be a good idea to have units translatable as well. I know for a fact that in the former Soviet bloc SI units were not always used, and some (older) people there might be more comfortable with translated versions. I believe even the Greek letter mu for micro had its own (two cyrillic letters?) abbreviation. I also never understood why "Bat." and some other English-only strings is not translatable in either firmware.

[jm_araujo]

Please can you post your compiled version. I have the same problem with the M Version.
I don't have experience with compiling.
Thanks.

Sure! It's attached. As I've changed my crystal to 20MHz and seems some people change theirs to 16MHz, I include compilations for the 3 different speeds.
My fuses are set as L:0xF7 H:0xD9 E:0x04

All the credits should go to flywheelz for making the changes for AY-AT, and indman for finding the LCD_RES bug.
And of course to madires for all the great work!!

[Mek]

post internal foto's

you need to replace the atmel with hot air and obviously program the replacement.

This is it. But even if I manage to replace the atmel, I cannot seem to find the program to flash. This Chinese clone of transistortester is not mentioned in the docs. Am I missing something?

[perieanuo]

Please can you post your compiled version. I have the same problem with the M Version.
I don't have experience with compiling.
Thanks.

Sure! It's attached. As I've changed my crystal to 20MHz and seems some people change theirs to 16MHz, I include compilations for the 3 different speeds.
My fuses are set as L:0xF7 H:0xD9 E:0x04

All the credits should go to flywheelz for making the changes for AY-AT, and indman for finding the LCD_RES bug.
And of course to madires for all the great work!!

Tks I tested 8Mhz it works.inductance seems not functional btw.nice job.tomorrow or monday I'll test the 20 MHz.
Best regards from France


Envoyé de mon iPad en utilisant Tapatalk

[stj]

post internal foto's

you need to replace the atmel with hot air and obviously program the replacement.

This is it. But even if I manage to replace the atmel, I cannot seem to find the program to flash. This Chinese clone of transistortester is not mentioned in the docs. Am I missing something?

the 2x6 holes left of the crystal are for programming,
now we know it's by "Fish8840" we can experiment with a few firmwares to get it right.

before that, who did that disgusting soldering, and messed with the 6 resistors under the cpu?
because that has to be fixed first.

[Mek]

post internal foto's

you need to replace the atmel with hot air and obviously program the replacement.

This is it. But even if I manage to replace the atmel, I cannot seem to find the program to flash. This Chinese clone of transistortester is not mentioned in the docs. Am I missing something?

the 2x6 holes left of the crystal are for programming,
now we know it's by "Fish8840" we can experiment with a few firmwares to get it right.

before that, who did that disgusting soldering, and messed with the 6 resistors under the cpu?
because that has to be fixed first.

It was me. The resistors had strange values while measured in-circuit so I de-soldered some of them to measure out of circuit. Two were OK (according to their values), one was completely wrong so I replaced it with a standard 0.25watt one but that did not help in my problem. It's not visible in the picture, I took it out before taking the photo so the PCB is visible better (maybe I was too naive that only the smd resistors failed?). I only have a standard old 75w soldering gun and one micro-soldering station which has a thicker tip than I would like

//edit: I fixed the resistors, there are no shorts but it didn't help...

[Gandalf_Sr]

Mek,

Ideally, you would use a hot air rework station to remove the Atmel chip but it can be done just with a soldering iron, here's how.

1. Either with some very small cutters or CAREFULLY with an X-Acto knife (you can push the knife tip inbetween two legs and the sharp edge will cut through a leg while the blunt edge pushes against the other pin), cut all the legs off the old Atmel chip LEAVING THEM SOLDERED TO THEIR PADS.
2. With tweezers and the soldering iron, carefully desolder each pin one at a time - don't pull hard with the tweezers, just wait for the solder to melt - it sounds couter-intuitive but you may need to add more solder to each pad/pin at this stage to make it easier for the heat to flow
3. After all pins are removed, use solder wick (that you've previously wiped with a flux pen) to remove the excess solder from the pads - don't pull at the solder wick if it gets stuck to the pads, wait for it to heat up so that it lifts on its own
4. Clean the area with a cotton swab and clear alcohol (I use vodka )
5. Put fresh solder on ONE PAD then position the new IC and solder that 1 pad making sure the IC is aligned properly INCLUDING PIN 1 being in the right place
6. Now add solder to a pin on the other side of the IC and check alignment, once alignment is good, solder the remaining pads
7. If any pads are bridged with solder, use the solder wick braid wiped with flux pen and carefully creep up on the pads with excess solder to soak up the excess

You need a good (temperature controlled) soldering iron set to 350 C for lead free solder.  It's also good to have some form of magnifier if you have old eyes like mine.  Leaded solder (if you have any) will use lower temperature (around 310 C) and will be easier to work with

Even if 1 pads lifts, you can usually make it work by soldering that pad last and/or repairing with a piece of wire.

Good luck

[vinceroger]

post internal foto's

you need to replace the atmel with hot air and obviously program the replacement.

This is it. But even if I manage to replace the atmel, I cannot seem to find the program to flash. This Chinese clone of transistortester is not mentioned in the docs. Am I missing something?

the 2x6 holes left of the crystal are for programming,
now we know it's by "Fish8840" we can experiment with a few firmwares to get it right.

before that, who did that disgusting soldering, and messed with the 6 resistors under the cpu?
because that has to be fixed first.

Tom66 has somefirmware posted for a fish8840 tester so this maybe of help i will attach what i found

[Mek]

Mek,

Ideally, you would use a hot air rework station to remove the Atmel chip but it can be done just with a soldering iron, here's how.

1. Either with some very small cutters or CAREFULLY with an X-Acto knife (you can push the knife tip inbetween two legs and the sharp edge will cut through a leg while the blunt edge pushes against the other pin), cut all the legs off the old Atmel chip LEAVING THEM SOLDERED TO THEIR PADS.
2. With tweezers and the soldering iron, carefully desolder each pin one at a time - don't pull hard with the tweezers, just wait for the solder to melt - it sounds couter-intuitive but you may need to add more solder to each pad/pin at this stage to make it easier for the heat to flow
3. After all pins are removed, use solder wick (that you've previously wiped with a flux pen) to remove the excess solder from the pads - don't pull at the solder wick if it gets stuck to the pads, wait for it to heat up so that it lifts on its own
4. Clean the area with a cotton swab and clear alcohol (I use vodka )
5. Put fresh solder on ONE PAD then position the new IC and solder that 1 pad making sure the IC is aligned properly INCLUDING PIN 1 being in the right place
6. Now add solder to a pin on the other side of the IC and check alignment, once alignment is good, solder the remaining pads
7. If any pads are bridged with solder, use the solder wick braid wiped with flux pen and carefully creep up on the pads with excess solder to soak up the excess

You need a good (temperature controlled) soldering iron set to 350 C for lead free solder.  It's also good to have some form of magnifier if you have old eyes like mine.  Leaded solder (if you have any) will use lower temperature (around 310 C) and will be easier to work with

Even if 1 pads lifts, you can usually make it work by soldering that pad last and/or repairing with a piece of wire.

Good luck

Thank you for this detailed how-to. I was planning to use my dremel to cut out the old chip, it might work better than a knife. Anyway, I have to get my hands on a new atmel first

Tom66 has somefirmware posted for a fish8840 tester so this maybe of help i will attach what i found

Thank you. I think this is is an older version (the original one says "2.1" on startup) but if no newer is available, it is worth a shot. I bought an avrdragon a while ago (never really got to experimenting with it) but I believe I can use it to push the firmware to the chip once I have it.

[indman]

the resistor symbol interchanged)... interesting. 

It was the small error which is already corrected.

[bitseeker]

...
4. Clean the area with a cotton swab and clear alcohol (I use vodka )
...

Hmm, I thought vodka was for the operator after a successful operation, not the patient.

[Pukker]

Please can you post your compiled version. I have the same problem with the M Version.
I don't have experience with compiling.
Thanks.

Sure! It's attached. As I've changed my crystal to 20MHz and seems some people change theirs to 16MHz, I include compilations for the 3 different speeds.
My fuses are set as L:0xF7 H:0xD9 E:0x04

All the credits should go to flywheelz for making the changes for AY-AT, and indman for finding the LCD_RES bug.
And of course to madires for all the great work!!

Thank you jm_araujo,
Works fine, I used the 16 Mhz version.
Like to see the M-Version.

[upsss]

Hi, I stopped reading this forum about 6 months ago since I completed my tester.

What exactly is the advantage of increasing the crystal frequency, my original crystal is 8Mhz.  Is there one firmware version that is good for all the different crystals or do you need a specific version for each frequency? 

If you need a different firmware version for each frequency then which firmware version number corresponds for each frequency?

[stj]

16MHz does more accurate tests and can also test crystals and resonators upto about 10MHz

it is different firmware, it's included in any zips i post.

[Per Hansson]

Should an SCR be possible to read on the transistor tester?
Specifically a S2514NH. (Attached datasheet).
It shows up just as a 15ohm resistor. (I am suspecting something is wrong with the SCR).

[hapless]

This "tester" does not really test components, it simply tries to identify them, meaning that even if does correctly identify the component, there is still a chance that something might wrong with it.

Hi, I stopped reading this forum about 6 months ago since I completed my tester.

What exactly is the advantage of increasing the crystal frequency, my original crystal is 8Mhz.  Is there one firmware version that is good for all the different crystals or do you need a specific version for each frequency? 

If you need a different firmware version for each frequency then which firmware version number corresponds for each frequency?

The firmware version for different crystals stays the same. It is simply compiled with a different parameter for each frequency. If you change your crystal, you need a firmware compiled for it. Currently, only m firmware supports 20MHz, but both support 16 and 8, AFAIK.

[stj]

i was refering to the hex files being different.

[GBowes]

Should an SCR be possible to read on the transistor tester?
Specifically a S2514NH. (Attached datasheet).
It shows up just as a 15ohm resistor. (I am suspecting something is wrong with the SCR).

This device is capable of recognizing Thyristors IF the gate current is <~ 5-6mA.
Your SCR requires minimum 20mA so cannot be recognized. Your SCR could well be OK.

Graham

[indman]

Hi! Tried to use other character set 32x32 instead of 24x24 symbols. Result on a photo. The big or small size can be set, changing value #define to SYMBOL_RESIZE in the ST7735.c file.