$20 LCR ESR Transistor checker project

[madires]

What "ERROR!" means during adjustment in 1.43m ?
Closed/open calibration are OK, then it displays reference/comparator voltage, and ERROR.

That indicates that either the adjustment is skipped or a limit is exceeded:

Code: [Select]

Limits:
- probe resistance   < 1.50 Ohms for two probes in series
- probe capacitance  < 100 pF
- IO pin's internal resistance in low mode (RiL)   < 25 Ohms
- IO pin's internal resistance in high mode (RiH)  < 29 Ohms


Measured capacitors are 1.5..2 times bigger than nominal value (1.13K firmware measures much closer to nominal).
Also it frequently can't reliably detect component on 1-3 terminals, instead uses 1-2, 1.13k detects better.

M328P @8M, powered from LiPo with XC6206.
Vref LM431, divider resistors 10K/3K 1%, but instead of 3.2..3.3V it displays 3.53..3.56V - IMHO too big difference...

The transistortester is designed to run at 5 V, not 3.3. Have you adjusted BAT_OFFSET? BTW, the battery monitoring is meant to monitor the battery voltage and not Vcc.

[H202]

changes in config.h:
UREF_VCC = 3300
BAT_WEAK = 3100
BAT_LOW = 3000
BAT_R1 = 10000
BAT_R2 = 3000

in principle, battery control is not critical for me, can switch it off completely...

The transistortester is designed to run at 5 V, not 3.3

is this hardware or software limitation ?
3.3V at 8MHz must work reliably...

[H202]

A4,A5,A6

[madires]

The transistortester is designed to run at 5 V, not 3.3

is this hardware or software limitation ?
3.3V at 8MHz must work reliably...

Both, because 5 V is the sweet spot when checking semiconductors. Some SCRs or TRIACs with a higher trigger voltage or current  require even more and can't be tested.

[H202]

its possible to auto-detect SSD1306/SH1106 - read register 0 before initialization.
SH1106 & clones contain 0x28/0x48/0x56 - add 2 pixel right-shift

[madires]

Basically it should be possible to merge both drivers into one. However, the auto-detection requires an additional signal line (MISO) and the driver's size would increase (plus higher RAM usage for additional variables).

[H202]

powered from 5V - got the same "Error!".
my schematics:

[madires]

Have you set UREF_VCC back to 5000? Have you measured a film cap (220nF - 2.2µF) three times before running the self-adjustment? As I wrote above, some value might exceed the adjustment limit.

[indman]

H202,show hardware tests A1-A6 with +5V VCC

[H202]

ok, now works from 5V, pity not from 3.3V.
0.22uF ceramics measured 288nF before calibration, 242nF after.
but, sometimes falsely detects 2..22uF cap on 1-2 or 2-3 pins, though cap is connected on 1-3 pins, or not connected at all...

[madires]

That is caused typically by an unstable power supply, e.g. SMPSU or lack of bypass caps. Again, with 3.3 V a lot of semiconductors can't be detected. For example, most classic MOSFETs (not logic-level types) have a V_th around 4 V.

[H202]

I don't really need it, only R/L/C, and frequency.
thanks for the advice...

[Dumidan]

@H202:

Operating on 5V power supply brings some benefits that you should take into account:

1. all digital ICs operate at a higher frequency at 5V compared to 3.3V, so you will be able to measure higher frequencies;
2. at 5V power supply you will have higher values of test currents (those passing through 680 ohms and 470 kohm), which increases the measurement accuracy for R / L / C / ESR.

The problem of portability, the power supply from the Li-Ion battery, is easily solved with a module from a power bank. It allows the controlled charging of the accumulator and ensures the 5V power supply of the tester.

[madires]

3.3V will also effect the measurement ranges, i.e. lower maximum resistance and worse lower limit for inductance. And the firmware would need several changes too, like adapted tables for capacitance.

[GianS]

Anyone has a misaligned/titlted screen? Bought this TC1 variant from Amazon.it vendor "diymore®"
Took some photos and to me it seems to be the LCD itself that has been wrongly attached on its own board and not a soldering problem. Should I try to adjust it by resoldering? It's not really a problem but more an annoyance

And another question, since I wasn't able to find anything using the search option, isn't the power management (U5) usually a STC 15 series chip? Or am I looking at the wrong chip?
Nothing comes up looking up what is written on it
3G1K08
A772882
2044_XA (year/week code?)

[indman]

3G1K08

8G1K08
http://www.stcmicro.com/stc/stc8g1k08.html   
https://datasheet.lcsc.com/lcsc/2011152335_STC-Micro-STC8G1K08A-36I-DFN8_C915664.pdf
@GianS, You have one of the new variants of the clone TC1 circuit board with a different part marking U5 and a new STC processor

[TheBay]

Anyone has a misaligned/titlted screen? Bought this TC1 variant from Amazon.it vendor "diymore®"
Took some photos and to me it seems to be the LCD itself that has been wrongly attached on its own board and not a soldering problem. Should I try to adjust it by resoldering? It's not really a problem but more an annoyance

And another question, since I wasn't able to find anything using the search option, isn't the power management (U5) usually a STC 15 series chip? Or am I looking at the wrong chip?
Nothing comes up looking up what is written on it
3G1K08
A772882
2044_XA (year/week code?)

Send it back and get one from a different seller. I posted a few posts back about this TC1 from "diymore®",  it uses a clone of a clone PCB, different cheap case, misaligned LCD and really small battery.

I tried the T7 from the same seller and that has exactly the same board, casing, misaligned screen and small battery.

https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg3592094/#msg3592094

[madires]

Anyone has a misaligned/titlted screen? Bought this TC1 variant from Amazon.it vendor "diymore®"
Took some photos and to me it seems to be the LCD itself that has been wrongly attached on its own board and not a soldering problem. Should I try to adjust it by resoldering? It's not really a problem but more an annoyance

The display is usually a stack of the LCD and the backlight module glued together by strips of double sided tape at the edges. And that stack is glued down to the PCB also by double sided tape (sometimes sticky pads). So resoldering won't help. You can try to loosen the stack very carefully and glue it down again to the PCB.

And another question, since I wasn't able to find anything using the search option, isn't the power management (U5) usually a STC 15 series chip?

Yes. Looks like we have another designator (U4, U3 and now U5).

[H202]

the power supply from the Li-Ion battery, is easily solved with a module from a power bank

too much noise from step-up, hard to filter, I planned to completely remove switching regulators

3.3V will also effect the measurement ranges, i.e. lower maximum resistance and worse lower limit for inductance.

You calibrate pins resistance/capacitance anyway, so what the difficulty to work from stable 3V, even with higher pins resistance ?

[madires]

3.3V will also effect the measurement ranges, i.e. lower maximum resistance and worse lower limit for inductance.

You calibrate pins resistance/capacitance anyway, so what the difficulty to work from stable 3V, even with higher pins resistance ?

Ohm's law!

[Yuriy_K]

3.3V will also effect the measurement ranges, i.e. lower maximum resistance and worse lower limit for inductance.

You calibrate pins resistance/capacitance anyway, so what the difficulty to work from stable 3V, even with higher pins resistance ?

See how the tests should go ... and compare with yours.

[PBh]

Hello everybody,
Sorry to ask such a basic question in this huge subject, but it seems i need an appropriate firmware for my GM328 board.
All details are here: https://www.eevblog.com/forum/testgear/gm328-out-of-order/msg3610441/#msg3610441
Where to fine good hex file (for the moment) ?
Thanks,

[madires]

k-firmware: https://github.com/kubi48/TransistorTester-source/tree/master/trunk/mega328_color_kit
m-firmware: https://github.com/kubi48/TransistorTester-source/tree/master/Markus (see "Clones" for AY-AT settings)

[Mp3]

I'm having a bit of trouble finding out which build is for the Bside ESR02 Pro. My AY-AT is programmed fine now, but not sure what to do for ESR02 pro

[indman]

@Mp3 https://yadi.sk/d/yW8xa5NJgUo5z/BSideESR02(DTU-1701)/Firmware/Karl-Heinz%20K%C3%BCbbeler%20/English
https://github.com/kubi48/TransistorTester-source/tree/master/trunk/mega328_st7565