$20 LCR ESR Transistor checker project

[timelessbeing]

So you should be ashamed of your arrogant and biased attitude.

you should be ashamed of subjecting people to your room temperature IQ.   

[pupa]

Stan21,
1. DMM is the common designation for Digital Multi Meter! It's a shame if you did not know these simple things before this time.
2. VC-9808, Mastech MAS345 - this is DMM! They are not specialized LCR meters, but simply have additional bonus options for measuring inductance, capacitance and transistor parameters.
3. You bought the LCR-T4 clone model, which has a very old Chinese mod firmware, in which so many important tests and calibration settings have been removed. Update the firmware on your clone, calibrate it as it should and then compare the readings hFE.

Don't do nitpicking, 9808 has iductance, capacitance and resistance, hense LCR and this is how it is positioned on a market; MAS345 does not have inductance so it is not LCR, 5828 is not digital so it is not 'DMM'. And _ANY_ of this has nothing to do with subject. It is a shame for you to wase the thread with off-topics.
You don't know this is 'old Chinese firmware' and your guess is just a wishfull thinking. And that exactly model from the same seller had positive review 5 years ago. https://hackaday.com/2015/04/24/review-transistor-tester, and also a very good rating on Amazon.
When I by a 'tester', I want to open the box, connect a battery and start testing instead of wasting time on browsing 250-pages for the search of 'genuine warranted Snark' that may or may not make that crappy gadget functional. Well, obviously that does not work for a cheap gizmo.
So you should be ashamed of your arrogant and biased attitude. Have a potato.

What an arrogant and useless attitude. Yet you come here for help? What a total waste of this site's good will and recources to try and help someone like you!

What"s happening in your country seems to shine through very strongly in your attitude.

Farewell I hope.

[de_light]

Agree. Public thanks to madires and indman for their endless patience with me.

I am not familiar with your slang and have no idea what 'DMM' is.

 

[CatalinaWOW]

I am embarrassed to share a country with Stan21.  I am sure most recognize that in spite of the news reports his attitude is not the norm currently, and hopefully not for quite a ways into the future.

I have an early model of one of these testers, and am very pleased.  I use it more frequently than much of the brand name certified test gear that I own.   I follow this thread simply because I may be tempted to get a newer version and want to follow the options.

The patience of the supporters of this device is amazing to me.  They have continued to help people through thousands of questions, many repetitive, many of which deserved a seldom issued RTFM comment.  I salute them for their dedication and for the quality of the work they have performed. 

I also recognize the many, many who have shown their appreciation for the help they have been given.  They do represent the norm, not Stan21.

[de_light]

Cross-posted from my other thread for some good news....I'm slightly emotional!! 

---

Well. What a journey. Finally, I've managed to fix this and implement all of indman's recommended modifications. I went from not even knowing what flux was and not owning a DMM to replacing SMD components and hand-soldering wire onto IC pins!

Granted, I've almost destroyed the plastic housing through many errors with the hot soldering iron and the hot air gun, the board looks cr*ppy and the third port is barely usable, but it works!!! And I have 1.39m!!

It turns out the problem was with the eBay special USBAsp. I learnt how to use an Arduino as an ISP programmer with some online tutorials and hooked it up and it worked straight away.


Thanks to all who have contributed, esp indman and madires. Hopefully one day I can give something back to the project.

[indman]

de_light, I congratulate you on this victory!
This is a great example of the fact that if a person wants to achieve a result and comes to the forum for help, then he receives this help and listens to the advice of other people.

[bitseeker]

Exactly, indman.

[de_light]

Question: can anyone help to explain why I am getting some very odd readings for ESR and capacitance with some old capacitors I am replacing?
(unit has been calibrated/adjusted and tested with other devices and reading well, e.g. ceramic caps and film resistors)

For example, I removed a huge, 40 year old 5600uF rated electrolytic cap. I consistently got readings of 7765uF with an ESR of 0.33, over multiple readings. This was out of circuit.

Then, I tested some 490uF caps in circuit and they came back over 600uF.


Is this a question of tolerances? Or do caps increase their capacitance as they age? I've no idea.

[madires]

I've seen that too. I have a few 30+ years old electrolytics (Roederstein) from audio amp power supplies and they are still fine (checked with an LCR meter), just gained more than 20% capacitance. No idea why and how that happens. Most old Philips electrolytics of the same age are unusable (low capacitance, high ESR and some are also leaky).

If you measure caps in circuit there are usually other components in parallel. Since the tester measures capacitance via the charging time method any resistance in parallel will increase the charging time. Hence the larger capacitance value. The other components can also completely screw up the measurement, i.e. the tester aborts the measurement because of a timeout.

[indman]

Is this a question of tolerances? Or do caps increase their capacitance as they age? I've no idea.

Yes, all these reasons can change the capacitance of a capacitor in a big way.
In addition, an increase in electrolytic capacitance can occur due to a change in the property of the dielectric, which causes a decrease in the quality factor of the capacitor.
But this effect can be detected only when measured with a quality LCR meter.
Another reason, as madires correctly noted, may be an increased leak in the capacitor itself, which will be considered by the tester as an increased capacity.Since the tester measures capacitance via the charging time.

[CatalinaWOW]

While all of the bad reasons for these high capacitance values can be true, don't overlook the tolerance issue.  Spec tolerances on this type of capacitor are often 30 or 40%.  Quality suppliers would aim high since in the typical application high is good.  So most of what you are seeing could be just high value capacitors, with minor increases due to the other factors shown.

Pretty easy to check by just observing RC decay with a known resistor.

[madires]

Have fun!

v1.40m
- Fixed error in SSD1306 driver which caused component symbols placed wrongly (reported by Andrei Paul).
- Changed avrdude configuration in Makefile to be more user friendly and to allow customized options.
- Added drivers for ILI9481 and ILI9486 based displays (8 and 16 bit parallel). Thanks to Bohu for providing an ILI9486 based display for testing.
- Fixed logic error for color displays when color feature is disabled.
- Added configuration switch for color displays to swap red and blue color channels (LCD_BGR).
- Improved R/L monitor to reduce spread of measurement values (reported by indman@EEVblog). Might not help in all cases.
- Fixed "#ifdef" issue for Display_HexByte() and Display_HexDigit() (reported by AlcidePiR2@EEVBlog).
- Support for ATmega 640/1280/2560. Thanks to Bohu for providing an Arduino Mega 2560 for testing.
- The detection of the rotation direction in ReadEncoder() was reversed. Changed to correct direction and updated settings in config_<MCU>.h and Clones.
- Fixed initialisation issue for hardware SPI. Also fixed some faults in SPI_WriteRead_Byte() and I2C_ReadByte() for bit-bang mode.
- Added alternative mode to Zener check in case the boost converter runs always or the circuit hasn't one (ZENER_UNSWITCHED, suggested by indman@EEVblog).
- Configuration switch for 100nF AREF buffer cap instead of 1nF to deal with some MCU boards (ADC_LARGE_BUFFER_CAP).
- Added alternative cyrillic fonts 8x16 (FONT_8X16ALT_WIN1251_HF) and 8x8 (FONT_8X8ALT_WIN1251_VF, thanks to indman@EEVblog).
- Updated Russian texts (thanks to indman@EEVblog).
- Option to use a manual power switch instead of the default soft-latching one (POWER_SWITCH_MANUAL).
- Added detection of two short presses of the center bar in ReadTouchScreen().
- Fixed fault in Touch_CharPos() regarding TOUCH_FLIP_X/TOUCH_FLIP_Y (reported by Bohu). 
- Replaced some ISO8859-2 fonts with updated versions provided by Bohu.
- Option for checking resistors for E series norm value (SW_R_E*). Also for capacitors (SW_C_E*) and inductors (SW_L_E*). Optional output of color code for resistors (requires color graphics display).

Available at https://github.com/madires/Transistortester-Warehouse/tree/master/Firmware/m-firmware.

[bitseeker]

Lots of good stuff! It may be mundane, but I like the option to have a real power switch.

What kinds of functions are folks using a ATMega 2560 for?

[madires]

What kinds of functions are folks using a ATMega 2560 for?

Using the additional I/O pins for driving a 3.5" 320x480 display via 8 or 16 bit parallel bus. Anyhow, there are a lot of Arduino enthusiasts who prefer to do projects based on Arduini and won't touch "bare-bone" ATmega boards.

[bitseeker]

Oh, bigger display. That's cool.

[indman]

Have fun!
v1.40m

Another addition - the Clones file has been updated, configurations for BSideESR02 (DTU-1701) and Arduino Uno (Mega) 2560 have been added to it 

[Pukker]

Have fun!
v1.40m

Another addition - the Clones file has been updated, configurations for BSideESR02 (DTU-1701) and Arduino Uno (Mega) 2560 have been added to it 

Is there a precompiled v1.40m available for the BSideESR02?
Thanks in advance.

[snapper]

Hello
search working HEX files and fuse settings for the GM328
Transistor Tester (from Banggood) because I have the Atmega
shot. The original seems to be protected against reading :-(
TX7014DH is on the O-Led, thanks for a feedback

[madires]

Is there a precompiled v1.40m available for the BSideESR02?

If someone likes to support the project by providing precompiled firmwares for different clones I would upload them to the GitHub repo.

[madires]

search working HEX files and fuse settings for the GM328
Transistor Tester (from Banggood) because I have the Atmega
shot. The original seems to be protected against reading :-(
TX7014DH is on the O-Led, thanks for a feedback

Your tester is an AY-AT clone with an ST7735 based display and it's running the k-firmware (or a modified version). Please try mega328_color_kit (https://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/). The AY-AT is also supported by the m-firmware (see Clones files in the firmware archive). Fuse bits are lfuse 0xf7, hfuse 0xd9 and efuse 0xfc.

[indman]

madires, You could not show in the photo what your firmware 1.40 looks for ILI9481 or ILI9486 Arduino Mega 2560?

[madires]

Since you're asking so nicely, Mega2560 with ILI9486 based display via 8 bit parallel bus:

[indman]

Madires Thanks for the photo, it looks great! I have a 3.5 display on the ILI9481 and Arduino Mega2560. I will try to repeat your design.

Have fun!
v1.40m
- Option for checking resistors for E series norm value (SW_R_E*). Also for capacitors (SW_C_E*) and inductors (SW_L_E*). Optional output of color code for resistors (requires color graphics display).

This option can be very useful for many people, thanks madires!
I looked at her work in Proteus and she looks very attractive. Only I did not find information on a series of E24 with a tolerance of 1%. The standard E24 series implies a tolerance of 5%. Can you explain this?

[pepe10000]

For madires.

New Spanish translation file with the latest additions.

Thanks and best regards.

[madires]

Thanks for the photo, it looks great! I have a 3.5 display on the ILI9481 and Arduino Mega2560. I will try to repeat your design.

Please let me know if the ILI9481 driver works because I don't have such a display yet for testing. The ILI9481 is very similar to the ILI9486, just needs a different initialization. So the ILI9481 driver is basically a copy of the ILI9486 one with an adapted initialization.

This option can be very useful for many hams, thanks madires!
I looked at her work in Proteus and she looks very attractive. Only I did not find information on a series of E24 with a tolerance of 1%. The standard E24 series implies a tolerance of 5%. Can you explain this?

It's an inofficial standard. Some E24 values are also part of E96, and some aren't. Several manufacturers added the missing E24 values to their E96 1% resistors (it's a mix of E96 and E24) because of customers' demand.