$20 LCR ESR Transistor checker project

[madires]

Sorry! I've updated the link.

[Per Hansson]

I would be very grateful if you could give some idea where you think the issue is with the K-firmware that I see.
Am I on the right path with trying to adjust "FAKTOR_ESR" or was there some other much more imprtant thing you had to change?

"FAKTOR_ESR" Only works for 20nF - 200nF capacitors. For electrolytic capacitors, I changed a few places. But I consider myself understanding enough in Assembler to lecture Karl-Heinz. Who does not fit my firmware, do not use. I can't help anymore.

I can understand that you are tired of me Yuriy_K but I really like your dedication!
I used the latest GIT version with only this code replacing line 832:

Code: [Select]

#if (PROCESSOR_TYP == 644) || (PROCESSOR_TYP == 1280)
        #define FULL_PULSE_LENGTH_TICS ((HALF_PULSE_LENGTH_TICS*2) - 1)
#else
#define FULL_PULSE_LENGTH_TICS ((HALF_PULSE_LENGTH_TICS*2)+(MHZ_CPU/14))
#endif
With this change I have the following result:

Code: [Select]

GM328R 20MHz: Hiland644-1*: Hiland644-2*: Hiland644-3*: Hiland644-4*
20mΩ resistor: 0.01Ω 0.00Ω 0.15Ω 0.01Ω 0.03Ω
50mΩ resistor: 0.04Ω 0.03Ω 0.19Ω 0.05Ω 0.06Ω
47nF film cap: 46nF 0.50Ω 46.0nF 0.00Ω 46.1nF 1.10Ω 46.1nF 0.23Ω 47.1nF 12.0Ω
330nF film cap: 319.2nF 0.10Ω 316.7nF 0.00Ω 317.4nF 0.23Ω 316.3nF 0.12Ω 324.7nF 1.74Ω
2200µF lytic (KMG): 2326µF 0.10Ω 2327µF 0.07Ω 2229µF 0.28Ω 2470µF 0.08Ω 2294 0.11Ω
1000µF polymer (PSG): 980µF 0.02Ω 980µF 0.04Ω 942µF 0.13Ω 1044µF 0.05Ω 960µF 0.01Ω
Hiland644-1*= Latest GIT release, no changes (unable to read ESR of small caps).
Hiland644-2*= Latest GIT release, changed GetESR.S according to code above. (reads small caps but with a bit high ESR, same for resistors)
Hiland644-3*= Latest GIT release, same as Hiland644-2 but also changed FAKTOR_ESR on line 578 to: 550000 (reads pretty good!).
Hiland644-4*= M-firmware 1.48m-beta (added by edit later for comparison).

But I don't understand the purpose of the original code:

Code: [Select]

#define FULL_PULSE_LENGTH_TICS ((HALF_PULSE_LENGTH_TICS*2)+(MHZ_CPU/14))I checked the source and "MHZ_CPU" is defined as the frequency in Hz divided by a million, so it is for example "8" with 8MHz CPU.
"HALF_PULSE_LENGTH_TICS" is defined a very similar way.
What I don't get is why it is then divided by the frequency of the CPU by the number 14?
And in your changed version in my example code above this is instead "-1" if the CPU is Atmega644, but why?

[edgard22]

Yes, it is the same to connect only 2 terminals to see the junction capacitance, but sometimes it is inconvenient when there are many transistors. Anyway I copied a few lines of code in the BJT sector and I achieved the task.
In the photos you can see measurements of several 2SC5200 of different qualities. The one that shows Cbe460pF is very bad, measured with another instrument it has a Vbr of 130V (The originals generally measured Vbr above 320V)

[Yuriy_K]

Yes, it is the same to connect only 2 terminals to see the junction capacitance, but sometimes it is inconvenient when there are many transistors. Anyway I copied a few lines of code in the BJT sector and I achieved the task.

Incorrect measurement examples, you cannot compare I_E = 6.25mA readings with I_C = 0.935mA readings. The tester incorrectly detects the emitter and collector pins. From this, the capacity of the transition "eb" is incorrectly determined. Measure on individual wires and see if I'm right.

[Yuriy_K]

I can understand that you are tired of me Yuriy_K but I really like your dedication!

I showed my settings, measurements and firmware with corrections on page 311. I have nothing more to say.

[boneDragon]

on 1.45m firmware, on 16M MCU crystal single measurement takes 10..30sec, is it possible to make it faster ?
or leave only R/C/L mode, disable all others to make faster detection

[indman]

on 1.45m firmware, 16M crystal single measurement takes 10..30sec, is it possible to make it faster ?

M-firmware tests crystals only if there is an extended version of the frequency meter! Which version of the clone (device)are you using?

[boneDragon]

thats MCU crystal, I measure only R/C/L elements

[indman]

Check if you have programmed the MCU fuses correctly?
H:D9 L:F7 E:FD(FC)

[boneDragon]

tried - nothing changed. Measured with frequency counter - 16M generation on crystal is ok

is it possible to disable TP2 probing ?
test clips connected to TP1/TP3, but sometimes it detects component on TP1/TP2

[indman]

is it possible to disable TP2 probing ?

There's no need for that.Read the section in the manual for the tester where it is indicated how to start the self-testing procedure and show us these results.

[Yuriy_K]

Sorry! I've updated the link.

I looked, I re-quote the transistor measurements from the previous page. The unconnected lead lies on top of the case. For the bottom row I will explain by numbers:
1. base and collector are connected together,
2. The сollector lead not connected,
3. The emitter is not connected,
4. The emitter is connected to the collector,
5. The base is not connected.

The examples shown show that not connecting free terminals has little effect on the readings of the capacitances of the junctions.

[madires]

on 1.45m firmware, on 16M MCU crystal single measurement takes 10..30sec, is it possible to make it faster ?
or leave only R/C/L mode, disable all others to make faster detection

Are you talking about measuring large capacitors?

[madires]

The examples shown show that not connecting free terminals has little effect on the readings of the capacitances of the junctions.

Thanks for checking! The capacitance between the  terminals is a bit more complex because there a several capacitances adding up. The capacitance of the leads, junction capacitance and diffusion capacitance. The latter two change with bias, frequency, temperature and so on. Anyway, if 'third terminal open' provides a usable value then we can use this method.

[boneDragon]

Are you talking about measuring large capacitors?

yes

simply shorted pins PC1,PB2,PB3 (TP2) - now measures much faster and no false detections...

[indman]

simply shorted pins PC1,PB2,PB3 (TP2) - now measures much faster and no false detections...

Nothing is clear from your explanation because you don't state your problem correctly from the start and no name your clone model. There are no psychics here to guess at your measurement difficulties.

[madires]

Are you talking about measuring large capacitors?

yes

As larger the capacitance as longer it takes. This is normal for the measurement method used.

[indman]

As larger the capacitance as longer it takes. This is normal for the measurement method used.

Madires,that's right,but not 30 seconds,even if he is it measures 100mF capacitance!
Capacity of 10mF is measured by m-firmware with quartz 16MHz for 5-6 seconds, the capacity of 100mF -15 seconds!

[boneDragon]

found crack on PC1 trace, so maybe it was catching noise from near tracks.
now all works fast

[madires]

Glad you found the cause. I can't remember that I ever heard of that issue, i.e. a broken trace causing a delayed probing cycle.

[edgard22]

Yes, it is the same to connect only 2 terminals to see the junction capacitance, but sometimes it is inconvenient when there are many transistors. Anyway I copied a few lines of code in the BJT sector and I achieved the task.

Incorrect measurement examples, you cannot compare I_E = 6.25mA readings with I_C = 0.935mA readings. The tester incorrectly detects the emitter and collector pins. From this, the capacity of the transition "eb" is incorrectly determined. Measure on individual wires and see if I'm right.

You are right, but the values ​​read with the multimeter, although they differ a little from the AY-AT, maintain a relationship. I believe that an exact value is not necessary since it is used as a reference and it is possible to clearly differentiate them in a primary classification.

[boneDragon]

Glad you found the cause. I can't remember that I ever heard of that issue, i.e. a broken trace causing a delayed probing cycle.

is it possible to increase parameters indication time, before next measurement ?

small 128x32 0.91" OLEDs are supported, or only 128x64 ?

[Per Hansson]

is it possible to increase parameters indication time, before next measurement ?

You can change it here in config.h:

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/*
 *  Maximum time to wait after probing (in ms).
 *  - applies to continuous mode only
 *  - Time between printing the result and starting a new probing cycle.
 */

#define CYCLE_DELAY      5000
But you can also instead enable this and the tester will wait for button or encoder input to measure again:

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/*
 *  Set the default operation mode to auto-hold.
 *  - instead of continous mode
 *  - uncomment to enable
 */

#define UI_AUTOHOLD

[madires]

... or you can start the tester with a long button press (>300ms) to enter the auto-hold mode.

[Yuriy_K]

madires
I will try to explain the identified problem in main.c. When checking on the "m" firmware of the specified transistor, in my opinion, a very important parameter Vbe was missing. The given corrections allow to show this value. I understand that my solution looks primitive. I hope you find a better solution...