$20 LCR ESR Transistor checker project

[garymck]

Thanks,
this got me close, the device now boots, but the graphic screen is unreadable.

Must be a fuse option? I'm using the DIY M12864 Graphics Version...
cheers
Gary

AVRDude reports not error messages

this is the string i use:

avrdude -c USBasp -P usb -p m328p -U flash:w:TransistorTester.hex \-U eeprom:w:TransistorTester.eep \-U lfuse:w:0xf7:m \-U hfuse:w:0xd9:m \-U efuse:w:0xfc:m

THIS WONT WORK ON WINDOW$10

[stj]

your problems are not the fuse bytes.

if you use windows10, it will cut that line short and only program some of the stuff.
if your on 10, you need to use seperate lines for the flash,eeprom and fuses.
or put it in a batchfile.

[hapless]

I got a report about a "black screen" PCD8544 when running the ATmega at 16 MHz. Anyone else with that problem? Strangely the PCD8544's datasheet doesn't give any hints about command execution times, or have I missed that?

IIUC, the controller is expected to complete most commands in 100ns and the clock ticks every 250ns. Other than that... I don't know where to find any relevant information on this. Individual modules may have timing-specific problems, I guess, but I'd still suspect something wrong physically (intermittent connection, incorrect wiring, etc). Tried a Nokia display it on my 16 MHz unit and it works well. *shrug*

NB: I'm using the m firmware for this. Haven't tested with k.

[garymck]

Hi
I'm using Widows 7 64 bit...
cheers
Gary

your problems are not the fuse bytes.

if you use windows10, it will cut that line short and only program some of the stuff.
if your on 10, you need to use seperate lines for the flash,eeprom and fuses.
or put it in a batchfile.

[garymck]

Tried it anyway and splitting the commands seems to work!

cheers
Gary

Hi
I'm using Widows 7 64 bit...
cheers
Gary

your problems are not the fuse bytes.

if you use windows10, it will cut that line short and only program some of the stuff.
if your on 10, you need to use seperate lines for the flash,eeprom and fuses.
or put it in a batchfile.

[stj]

well that's not good,
it means one of the "updates" has made it worse!!
7 never originally had that issue, only 10!! 

[Vtile]

I have a guestion regarding the tester. Are these available (in somewhat quality build) somewhere or as a kit. If these are sold as a kits or as a ready PCB units what is the magic string of words to find one.

I noticed that there is similar units in many auction sites on the net. Is there any specific things to identify the bad aples from the good ones?

[ebclr]

Magic words = avr+transistor+tester


https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20170613034920&SearchText=avr+transistor+tester

[Willem52]

Search for "GM328 ESR" or "GM328 Transistor Tester"

Look e.g. on AliExpress like:
https://www.aliexpress.com/w/wholesale-GM328-ESR.html?spm=2114.01010208.0.0.RLTD73&site=glo&SearchText=GM328+ESR&g=y&SortType=price_asc&groupsort=1&tc=af&initiative_id=SB_20170613034612

[Vtile]

Thanks. Ordering one of those xxxx328 based units, hopefully I don't end up with poor ripoff of the original excellent project. Too much work to hunt down all invidual components and ordering PCB somewhere, easier to get premade unit and maybe then modify it with better components if needed.   

I were actually hoping that there would have been somesort of "official" kit somewhere to support the project.

[madires]

So far no support of any kind from the Chinese manufacturers. It would be nice if they would send us samples of their copy of the Transistor Tester to enable us to keep the firmware compatible and provide working settings. A lot of the buyers don't even know that it's an OHSW project and that they can update the firmware. Sellers on ebay and what have you - also the manufacturers - usually don't add any hint about the project. A German maker magazine had a report about the Transistor Tester a few years ago and totally missed the OSHW project too (how embarrassing for them ). They all are missing the good stuff!

[madires]

Another update about the m-firmware. After moving the SPI functionality from the display drivers into a central SPI driver I've started with writing a driver for the ADS7843/XPT2046 touch screen controller. The central SPI driver is necessary for running several chips on the same bus, which includes things like changing the bus clock for different chips. The next step is to add touch screen support to the UI. My idea is to use the last character line for navigation and control, for example three buttons for back, forward and enter/go. For menus maybe also invisible up/down bars. What do you think?

[indman]

Madires,your project will be similar to this?

[madires]

The UI will stay the same, just with the option of a touch screen. The only visible difference would be up to three touch buttons in the bottom line. It has to be that simple to support small screens. I think three buttons at the bottom of a 2.4" screen is feasable.

[indman]

madires, i understood you correctly!  From the project which i stated above it is possible to use some ideas on the user interface?

[madires]

... when we got a tester with an ARM based MCU.

[stj]

it's my understanding that the entire concept is based around very extensive knowlege of how the DAC's and ADC's behave.

if you tried to port it from AVR to a different platform you would be back to square one.

[madires]

Yes, the most important points are the 5V operating voltage, the knowledge of the MCU specifics und the simple design. Moving to an ARM based MCU or something similar would require a lot of additional circuitry for 5V switching and ADC-ing. But it could provide the possibility of using additional voltages and higher currents. For the foreseeable future we'll stay with the 328 and 664/1284.

[hapless]

I think indman was referring to the UI when he said that maybe some ideas could be taken from it. Perhaps worth considering, though personally, I see nothing wrong with just three simple hotspot buttons for the functions that are currently handled by a rotary encoder or hardware buttons. KISS?

[bitseeker]

The next step is to add touch screen support to the UI. My idea is to use the last character line for navigation and control, for example three buttons for back, forward and enter/go.

Does that assume that, on such a tester, touch is the exclusive interface (no other controls, other than on/off switch)?

For menus maybe also invisible up/down bars. What do you think?

I'm not sure I follow what the invisible up/down bars refer to and why they're invisible. The back/forward on-screen buttons seem as though they'll work fine on the menus, although up/down buttons might be better for spatial congruence.

[madires]

It should be an option, i.e. you can choose between On/test push button only, rotary encoder, On/Test plus up/down push buttons or On/Test plus touch screen. Or you could use multiple in parallel. What I've meant with "invisible up/down bars" is using the top two character lines as up and the bottom two lines as down button, which would be handy for menus. Or the left three and right three columns to decrease/increase a frequency for example. Could be even better than visible buttons at the bottom. My goal is to create a simple and intuitive touch interface. So I'm trying to do some brainstorming with you all.

[maggotronix]

Is there an already-constructed tester available out there on aliexpress or banggood or something? Just plug and go? Or maybe I should just lump it & buy the Atlas DCA? Are there quantitative differences? I'm not interested in a "kit", I want it pre-made to use to construct my own projects.

[stj]

in that case, get the TC1 in a case with built in lithium battery that also tests zener diodes.

http://www.ebay.co.uk/itm/272671833854

[pepe10000]

Hi.

I'm having some problems with the latest firmware revisions k (722 and 723) in measuring medium-low resistors value with my LCR-T4-H testers.

However with 729 and previous revisions work perfectly.

I attached some photos of the problem in question.

Is someone else going on?

Thank you and greetings.

Hi, after much research I think I have found the problem of measurement error in low value resistors in my LCR-T4-H.

It all started when I installed a voltage regulator MCP1702T-5002E more precise than the 78L05 and replaced the two diodes 1N4148 with an AMS1117-3.3v.

At first and with the old firmwares worked well, but with the most modern fimwares began to fail.

The problem seems to lie in the filtering of the main voltage of 5v for these LDO, in a Russian forum I saw a similar problem of measuring quartz crystals with nothing fitted in the zocalo ZIF, and applying the proposed solution to my tester has been Corrected said measurement of resistances of low value.

The solution consists in adding 3 capacitors of 100nF to the power and the reset of the Atmega328.

Attached two photos, one of the Russian solution and another of the capacitors I have put in my tester.

A greeting.

[carrascoso]

Hi.
Do not discharge a capacitor and break the IC.
Change it and use it to modify it as you can see in the images.
Program it and just turn on the led but nothing appears on the screen.

If I put a led in the test socket flashes and seems to be recognizing it, I put a link where it can be seen.
https://mega.nz/#!F8ACmKJZ!TLnpOIBjWBGafHaxHDqsrOvFWGPSvqfUsWK4r1fBG8o

Any solution?

Thank you