$20 LCR ESR Transistor checker project

[pepe10000]

For example:
 

[innkeeper]

THANKS!

[innkeeper]

the kit came before the better tolerance parts .. but .. I can't resist building it ... no self control what can i say.
heck the better tolerance parts and the spare atmega cost as much shipped as the kit.. shesh.

Shiny red button syndrome

[mauroh]

Hi madires,
     I think I lost the results of the beta testing of the new ESR function...
Do you need more beta tests from us?
Ciao
   Mauro

[madires]

So far you're the only one testing the modified ESR measurement. It would be nice if a few more could check it out.

[mauroh]

I think indman is the only one you are referring to and the only one that reported some results here
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1284997/#msg1284997
I only compiled and normaly used during some repair.
What you expect to receive as useful feedback?
- ESR displayed for low caps?
- comparison with the old m or k firmware with the same components?
- more accurate and or precision measurements?
If you want I can try something specific on my unit.
Mauro

[BradC]

So far you're the only one testing the modified ESR measurement. It would be nice if a few more could check it out.

I have plenty of caps but only a Bob Parker ESR meter to compare against. Is that any use?

[madires]

Yes, of course. Sorry indman! The ESR measurements of a few caps like 10nF, 47nF, 100nF, 220nF, 470nF, 10µF, 100µF and 1000µF with the m-firmware including the ESR mod and some other ESR meter would be helpful. And the test frequency of the other ESR meter (select 1kHz if supported).

BTW, I'm working on a PCB for the enhanced frequency counter hardware option at the moment.

[innkeeper]

So far you're the only one testing the modified ESR measurement. It would be nice if a few more could check it out.

soon as my parts arrive, id be willing to check it out as i will ahve a spare atmega to load

i've got a nice de-5000 to compare it against. jsut need to figure out how to load an atmega lol.  been a while since i've played with them.

[MikeL]

Here's a pic of the finished AY-AT tester.  This is one on which the SMT-test pads are mis-labelled, the one marked 3 is 2 and vice versa - I guess this may be why the instructions I got say to only use the chip-holder when doing the self-test.  Seems some of the boards have been made with correctly labelled, incorrectly labelled, and unlabelled SMT Test pads, still going through the thread...

[jakeisprobably]

 Must feed the Wumbus

    This is a comparison of all of the display options sans the Nokia 1100 (PCF8814). I could not find visual area measurements on it. Most of the measurement and range data is from buydisplay.com. This list is subject to errors as I have not double or triple checked my work. I made this casually just to have a basic idea of how each display compares in size. I collected a good bit more data including the part numbers referenced, the "compatible IC's" and interface options for almost all of these. That probably needs to go on a spreadsheet instead of directly here.
The basic visual area numbers are as follows:
16×2 XL
VA 99×24mm
20×4
VA 76×25mm
ST7920 2.9"
VA 72×40mm
ILI9341 3.1"
VA 49×65mm
ST7565 2.6"
VA 65×37mm
16×2
VA 65×15mm
NT7108 2.9"
VA 62×44mm
16×4
VA 62×25mm
ILI9341 2.2"
VA 39×55mm
ILI9342 2.3"
VA 47×35mm
12×2
VA 46×14.5mm
ST7565 1.4"
VA 36x20mm
SSD1306 1.3"
VA 31×17mm
SSD1306 0.96"
VA 24×13mm
SSD1306 0.49"
13×7mm (untested)
ST7036
VA 51×15mm
ST7735
VA 38×32mm
PCD8544
VA 36×26mm
PCF8812
VA 22×30mm

[innkeeper]

@madires
got my ISP running and received my spare atmega so,I'm happy to help out testing beta ESR code if you like.
just need to know where the beta code is. 

[jakeisprobably]

@madires
got my ISP running and received my spare atmega so,I'm happy to help out testing beta ESR code if you like.
just need to know where the beta code is. 

Original Post
The File
The last reply (I think)
 

[innkeeper]

got the precision resistors and voltage reference installed now
working out all the right config settings / fuses still for the m version of the firmware on my AY-AT.
so far just getting a white screen.

[madires]

The settings for the AY-AT are listed in the "Clones" file.

[mauroh]

Hi Markus,
    I made a quick test on few capacitors to test the beta and found strange results.
Referring to the attached picture, in the upper part you can find the measurement of the ESR made with the k firmware, in the lower part, the beta m.
I think this are similar results to the one indman reported.
The current 1.29m is not detecting the ESR of any of this capacitors but the 220n one that it is detectes a 0.7ohm, up to 1.5ohm (multiple measurements)
Mauro

[madires]

Thanks! The ESR measurement in 1.29m is only performed if the capacitance is larger than 180nF (beta: >= 10nF). Low values like 220nF may vary with the old ESR measurement method. The huge difference for low value caps between k-firmware and the beta m-firmware is interesting. While working on the beta I've cross-checked the results with a proper LCR meter (1kHz) and the ESR values matched reasonable in most cases. Let's wait for more beta results, maybe in comparison with a professional LCR meter (1kHz test frequency).

[innkeeper]

@madires

got it

here are the measurements using your code in 1.29m
DE-5000 set to 1khz
ESR in ohms

de-5000 218.1nf    10.46 ohms
tester  224.7nf     3.20 ohms

de-5000 922.8nf     1.18 ohms
tester  944.9nf     0.85 ohms

de-5000 10.223nf   55.51 ohms
tester  10.29nf   107.50 ohms

de-5000 152.45uf    3.22 ohms (known bad electrolytic)
tester  191.4uf     2.66 ohms IL 2.48ua

de-5000 976.0nf     0.12 ohms (very high quality cap)
tester  984.1nf     0.78 ohms

[penmarker]

I've bought one of the M328 variants and I think I might have buggered it. Here's the link to the model I got.
http://www.ebay.com.my/itm/142372146504

When I first turn it on, it went through the self test sequence. After its done, it shows the Menu screen then changes to show battery ok and then Vext=0 flashing.
I googled and found this thread, someone got it too but he rectified it. Another poster mentioned it could be a cold solder joint.
I went back and reflowed everything and it works again for a while. Then it goes to the flashing Vext=0 again.
Reflowing again makes it work again, but after the components cooled off it flashes Vext=0 again.
At one point it worked long enough that I managed to put together the case, and then it refused to work again.

What could it possibly be?

[innkeeper]

does the led come on?

[stj]

that's an AY-AT,
v-ext may mean the reference - check the connections to the TL431

[penmarker]

does the led come on?

Yes the LED comes on. Thankfully I don't have the problem with the LED like some others that need to press and hold the encoder to keep it on.

that's an AY-AT,
v-ext may mean the reference - check the connections to the TL431

I do have an extra TL431 for cases like this. Thanks a lot!

[penmarker]

Rechecked the connections to and from the TL431, replaced the TL431 as well. Still wouldn't work.
I reflowed again several times and it did work again once for several minutes. Tried reflowing a few more times but it wouldn't work.
At wits ends now. Buying is cheap but I'm gonna have to wait for another 3 weeks of shipping.

[stj]

bad chip socket contact?

[carrascoso]

I've bought one of the M328 variants and I think I might have buggered it. Here's the link to the model I got.
http://www.ebay.com.my/itm/142372146504

When I first turn it on, it went through the self test sequence. After its done, it shows the Menu screen then changes to show battery ok and then Vext=0 flashing.
I googled and found this thread, someone got it too but he rectified it. Another poster mentioned it could be a cold solder joint.
I went back and reflowed everything and it works again for a while. Then it goes to the flashing Vext=0 again.
Reflowing again makes it work again, but after the components cooled off it flashes Vext=0 again.
At one point it worked long enough that I managed to put together the case, and then it refused to work again.

What could it possibly be?

I had the same problem and was open the 27K resistor that goes between collector of transistor S9014 and pin7 of Mega 328