$20 LCR ESR Transistor checker project

[madires]

You could try following:

In display.c, function Display_Value() change

Code: [Select]

    if (Offset > 0)                     /* dot required */
to

Code: [Select]

    /* dot required or 4-digit value */
    if ((Offset > 0) || (Value >= 1000))

Edit: Will be an option in the next firmware version.

[Kim Christensen]

At first, I tried something similar to your solution madires. But found that some calls to Display_Value() returned unwanted results. One I remember was the self tests and corrections mV readouts being in volts.
So in the end, I wrote my code so it only changed the default behavior for certain calls to Display_Value(). I'm sure there's a more elegant way than my solution.

[madires]

The only value looking a bit strange should be T6 (Rh+) in the self test. It's near Vcc, e.g. 4990. 4990 would become 4.980k (because it's just a plain number).

@all: Please tell me if you encounter other strange values when testing the modification for 4-digit values!

[edgard22]

Thanks, I haven't tested it thoroughly but everything seems to be ok.

Gracias, no he probado a fondo pero parece estar todo ok.

[Feliciano]

The only value looking a bit strange should be T6 (Rh+) in the self test. It's near Vcc, e.g. 4990. 4990 would become 4.980k (because it's just a plain number).

@all: Please tell me if you encounter other strange values when testing the modification for 4-digit values!

For normal and ESR capacitor measurements, the new dot option works for me.
Indeed the more noticeable "strange" results are in the SelfTest: I don't mind T1 showing 1.1xxV, but T6 showing 4.9xxK(mV) can be confusing. I think that part would require a little adjustment too

[madires]

Also, three times 4.9xxk plus two spaces exceeds a line length of 16 chars. The new firmware version will come with a simple workaround when 4-digit values are disabled.

[indman]

madires, there is a suggestion to implement the possibility to disable the "Selftest" option in the firmware? This will save some memory, as this procedure is usually done only a few times when hardware problems are detected. Now I disable this option myself if I compile the firmware for myself. If I am sure that my circuit is correct, I only need the "Self Adjustment"option. If any strange results appear, you can always enable self-test if necessary or use the standard firmware where this option is enabled.

[madires]

Ok, I'll add that to the to-do list.

[madires]

Disabling the self-test reduces the firmware size by about 86 bytes (and a few bytes in the EEPROM). I also replaced a few similar function calls of Display_Value() with a new convenience function, freeing up another 50 bytes.

[madires]

Bohu has updated the PDFs (for firmware 1.52m, Czech, English and German): https://github.com/madires/Transistortester-Warehouse/tree/master/Documentation

[szpila]

Hi @madires

Updated translation file for UI_POLISH up to v1.52

[dave356]

Hi guys,

Need a replacement screen for this:

Looking around but I don't know what I need.
Any help will be appreciated.

[madires]

That should be an ST7565 based LCD.

[indman]

dave356, type this on the Aliexpress website in the search field "12864B5 14PIN 12864 COG dot matrix LCD display COG LCD module COG12864 standard screen with backlight" or find this seller DUOWEISI Module Store. He has what you need.
https://www.aliexpress.com/item/4000405795974.html

[jewelie]

Q:  Is there anyone out there that can help me make sense of what I'm seeing on the the Cap Leakage function on 1.52m? 

1. First there's the setup screen, I insert the properly oriented capacitor (e.g. with a 470uF 16V, but same with 100uF 35V, 100uF 16V etc) and trigger it.

2. Then I see "Charging Rl" with a progressively increasing current and voltage displayed until it hits about 5V (as measured with a DMM across the capacitor.)

3. Then it changes to "Charging Rh", displaying another progressively increasing current and voltage (which appears to a negative offset from 5V DC as the voltage across the capacitor goes down) but if it's "Charging Rh" then why is the capacitor discharging in this state?  Sometimes the displayed values go down on a different run with the same capacitor though.

I feel embarrassed as I'm so confused.

(AY-AT/m328 color kit board that was pre-built but has high precision Rl Rh resistors, good 2.5V ref, I've put a 328 in from Farnell.)


EDIT:  Is it... 5V is applied via Rl, then when the current drop below a trigger point, 5V is then applied via Rh instead?  But then, why would the figures be displayed current capacitance voltage with refeference to GND as measured from Rl, but then during the Rh phase the figures are being show with reference to 5V instead.  So I'm still confused?