$20 LCR ESR Transistor checker project

[eti]

Something is with Your fw or my config because now I try with fw 1.13k Karl and all it's ok. I try Your older fw. I test 16MHz crystal and oscillation is correctly but LCD show wrong value. See picture.
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? Expand please.

[Szybkijanek]

On my new from Ali Hiland M644 with ST7565R and 8MHz crystal i can't test correctly in HF mode crystal in terms of 7-9MHz and 15-17MHz because LCD show wrong value like 10kHZ. Oscillations are correct (see picture in previous post - tests 16MHZ there) just LCD show wrong value on fw 1.41m. On fw 1.13k this is not a problem. Can anyone check it?

[madires]

I can reproduce that issue with my Hiland M644. For crystals around 8 or 16 MHz the difference to 8 or 16 MHz is displayed instead of the real frequency. I don't see that on another tester with an ATmega644 running at 16 MHz. I'm curious what causes this strange issue.

[Szybkijanek]

Hmm, interesting. Is better 16MHz crystal than 8MHz in Atmega644? More precise?

[madires]

I've found the cause and I'm working on a fix now. An MCU clock of 16 MHz doubles all frequency ranges (signal gen and frequency counter) and helps a little bit with some measurements.

Update: Fixed!

[eti]

Modified my LCR-T4 with the addition of an "HC-06" bluetooth module. Set the baud to 9600 and changed the name to "LCR-T4", tapped the serial O/P of the MCU and fed it to a 3K3 + 2K2 potential divider, to drop the UART level to a safe level for the "HC-06" bluetooth module (accepts 3.3V nominally), tapped off pin 10 of MCU to power the module only when the LCR-T4 is turned on, and finally connected to it over bluetooth, using "Serial Bluetooth Terminal": https://play.google.com/store/apps/details?id=de.kai_morich.serial_bluetooth_terminal&hl=en_GB&gl=US

Oh, and mounted the PP3 battery clip OUTSIDE the casing... duh.

[timelessbeing]

nice. What serial app is that?

[madires]

... and with an ATmega644 plus m-firmware you can enable remote commands and run Messtechniker's tools (for Windows) or write your own tool to control the tester. Haven't seen any app for mobile phones yet.

[eti]

nice. What serial app is that?

If you read my post, the link is at the top

[eti]

Okay, which version of the firmware is this as shown in the attached photos? This is the **original** firmware on my LCR-T4 which it came with, and to be honest, the graphics are MUCH clearer & nicer, and the calibration procedure MUCH simpler and more intuitive.

I'd like to find out which version this is so that I may enable UART on that (like I did in my previous post, the other day) and enable the sub-menus.

Ideas? Thanks!

[madires]

That's a modified k-firmware with a fancy GUI. Unfortunately the manufacturer of that clone didn't publish the modified source. The drawback of the fancy GUI is a higher flash usage, i.e. less flash for features (the ATmega328 has only 32kB flash memory).

[eti]

That's a modified k-firmware with a fancy GUI. Unfortunately the manufacturer of that clone didn't publish the modified source. The drawback of the fancy GUI is a higher flash usage, i.e. less flash for features (the ATmega328 has only 32kB flash memory).

As I'd surmised, thanks. Okay, so bearing that in mind, how do I calibrate the device when using my compiled firmware, so that the calibration process is as easy as it is on the supplied firmare? It's rather vague and cryptic on the custom one - the supplied firmware may be "dumbed down" but the calibration is MUCH easier to accomplish

[madires]

In case of the k-firmware you can trigger the calibration by shorting all three probes or via the menu.

[eti]

In case of the k-firmware you can trigger the calibration by shorting all three probes or via the menu.

Thanks. Was aware. I was asking how it can be made as simple and painless to calibrate as the retail firmware, not how to invoke it. 

[madires]

Don't both use the same process?

[eti]

Don't both use the same process?

Technically, maybe, but not UI and simplicity-wise.

[madires]

Unless you've enabled SHORT_UNCAL_MSG the k-firmware shows a text explaining the calibration process if the tester isn't calibrated yet. And during the calibration it tells you what to do anyway.

BTW, most people call it calibration, but it's actually an adjustment.

[Dumidan]

... how do I calibrate the device when using my compiled firmware, so that the calibration process is as easy as it is on the supplied firmare? It's rather vague and cryptic on the custom one ...

Have you tried to calibrate the newly installed firmware? What exactly seems "vague and cryptic" in reading what is written on the screen / what exactly does the device ask for? The first time he asks you to summarize the 3 testers - after that he continues alone until the step when he asks you to remove the short of the testers ... What is cryptic here? Or do you say so, unproven? How simple do you want the procedure to be? Have a voice command like "Hey, tester, calibrate yourself!", Or how?    

[eti]

... how do I calibrate the device when using my compiled firmware, so that the calibration process is as easy as it is on the supplied firmare? It's rather vague and cryptic on the custom one ...

Have you tried to calibrate the newly installed firmware? What exactly seems "vague and cryptic" in reading what is written on the screen / what exactly does the device ask for? The first time he asks you to summarize the 3 testers - after that he continues alone until the step when he asks you to remove the short of the testers ... What is cryptic here? Or do you say so, unproven? How simple do you want the procedure to be? Have a voice command like "Hey, tester, calibrate yourself!", Or how?    

Mock me if you will, but I feel you have misunderstood which firmware version I find cryptic - the supplied, retail unit firmware "Mtester" is not the one I am having issues with, as you implied.

No need to be a wise guy.

[Dumidan]

I probably misunderstood due to a mistranslation - I'm not a native English speaker. That's it, google translate also makes mistakes ... Please accept my apologies, I didn't mean to make fun of you.

[eti]

I probably misunderstood due to a mistranslation - I'm not a native English speaker. That's it, google translate also makes mistakes ... Please accept my apologies, I didn't mean to make fun of you.

I forgive you, don't think about it any more, we all make errors, you didn't mean to

[cigmas]

Would one of these units be suitable for in-circuit testing for failed capacitors? If so, which model?

I don't foresee needing an ESR meter often, but if it can be had for a budget price, it would be a nice asset. So much the better if it comes with other potentially useful (diagnostic) features for which I couldn't justify buying a dedicated, more professional device given my usage level.

[madires]

Kinda. The test voltage could be too high to get meaningful results when semiconductors are in parallel. A special low-voltage ESR meter would be better. All clones of the Transistortester (ATmega328 or better) are able to measure capacitance and ESR.

[cigmas]

Kinda. The test voltage could be too high to get meaningful results when semiconductors are in parallel. A special low-voltage ESR meter would be better. All clones of the Transistortester (ATmega328 or better) are able to measure capacitance and ESR.

Any specifically recommended (budget) products? I'm really not familiar with these devices.

[madires]

No, but you'll find usually some hints about pros and cons of various testers in the last 10 pages.