Author Topic: $20 LCR ESR Transistor checker project (Read 3451773 times)

indman · « **Reply #6350 on:** July 17, 2020, 05:53:10 am »

Quote from: pinguy on July 16, 2020, 09:36:30 pm

BTW, is the Q value shown on display the same Q as in the blue ring Q meter? i.e. Q=10 means 10 "rings"?

The author of this measurement algorithm is Pieter-Tjerk de Boer(PA3FWM)!

Here http://www.pa3fwm.nl/technotes/tn11b.html
he briefly and easily explained the general principles works of the multitester and also explained his algorithm for measuring small capacitances and inductances by the resonance method.

pierreraymondrondelle · « **Reply #6351 on:** July 17, 2020, 08:50:21 am »

Prominent piece of information. Thanks.

just a remark: remove the " \ " after html to make the link working.

indman · « **Reply #6352 on:** July 17, 2020, 12:48:59 pm »

Hello everybody!
I offer all owners of the AY-AT clone as well as the GM328A black board clone a slightly modified version of the m-firmware 1.40m in English! I showed the functions that fit into the firmware in the photo. I have added some color coding for some important messages.

You can download and check this firmware for 3 different processor frequencies - 8,16 and 20Mhz using the link from my resource https://yadi.sk/d/yW8xa5NJgUo5z/M328Kit%2BTFT/Firmware/Markus%20Reschke/English
If madires likes this mods, he can add it to his GitHub archive

madires · « **Reply #6353 on:** July 17, 2020, 01:31:33 pm »

The colored battery status is nice! If you send me a copy of the source I'll put it into the repo.

casinada · « **Reply #6354 on:** July 17, 2020, 08:31:29 pm »

Nice

timelessbeing · « **Reply #6355 on:** July 17, 2020, 09:16:08 pm »

I like the resistor color bands. Gives you kind of an instant confirmation. Too bad I don't have a color lcd.

indman · « **Reply #6356 on:** July 18, 2020, 11:55:00 am »

@timelessbeing you have a good incentive to build yourself such a device with a color display.

madires · « **Reply #6357 on:** July 18, 2020, 01:55:43 pm »

Quote from: timelessbeing on July 17, 2020, 09:16:08 pm

I like the resistor color bands. Gives you kind of an instant confirmation. Too bad I don't have a color lcd.

Get an AY-AT/GM328A clone or build a tester with an ATmega644 and a large color display like 2.8" ILI9341 or 3.5" ILI9486.

320x240 are ok with hardware SPI, but for 480x320 I'd strongly recommend the 8-bit parallel bus. And if you like to have a touch screen, choose a display with an ADS7843/XPT2046 touch screen controller (supported by the m-firmware). For the resistor color code enable SW_R_E24_5_CC, SW_R_E24_1_CC and/or SW_R_E96_CC. In case the colors aren't right you can adjust them in colors.h.

Per Hansson · « **Reply #6358 on:** July 19, 2020, 01:22:19 pm »

Can you help clarify K-firmware SVN revision 819:
Log Message: "LC frequency error with 20MHz"

Does it mean SamplingADC was not working with a 20Mhz quartz?

https://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/sampling_lc.c?r1=819&r2=818&pathrev=819

indman · « **Reply #6359 on:** July 19, 2020, 01:49:03 pm »

Quote from: Per Hansson on July 19, 2020, 01:22:19 pm

Can you help clarify K-firmware SVN revision 819:
Log Message: "LC frequency error with 20MHz"
Does it mean SamplingADC was not working with a 20Mhz quartz?

No, it doesn't. SamplingADC worked, but incorrectly determined the frequency of the resonant circuit compared to the same measurement at 8 and 16 MHz.This error was reported by one of the participants in the Russian-language forum.
Karl-Heinz corrected this error for revision 819.

Obelix2007 · « **Reply #6360 on:** July 24, 2020, 01:30:46 am »

Hello together,

at the testing of new firmware m-1.40 with FONT_6x8_ISO8859_2_VF i missing the Caracter "µ" in both Display's (ST7565R). I have also tested with other languages - same result, without "µ".

Sorry for bad english

.

Best regards Horst

madires · « **Reply #6361 on:** July 24, 2020, 10:01:55 am »

Quote from: Obelix2007 on July 24, 2020, 01:30:46 am

at the testing of new firmware m-1.41 with FONT_6x8_ISO8859_2_VF i missing the Caracter "µ" in both Display's (ST7565R). I have also tested with other languages - same result, without "µ".

Open bitmaps/font_6x8_iso8859-2_vf.h, go to FontTable[] and look for:

Code: [Select]

  0xff,        /* 0x05 -> b5 */

Change that to:

Code: [Select]

  0x05,        /* 0x05 -> µ (micro) */

Thanks for reporting the issue! BTW, the latest version is 1.40m.

indman · « **Reply #6362 on:** July 24, 2020, 10:12:42 am »

madires,the same error with the symbol is in the font 6x8_ISO8859_2_V_F font_8x12t_iso8859-2_vfp.h

madires · « **Reply #6363 on:** July 24, 2020, 10:46:02 am »

... and three more of the ISO8859-2 fonts. Thanks!

Obelix2007 · « **Reply #6364 on:** July 24, 2020, 07:47:27 pm »

Hello,

... not all Problems are so easy, thank you madires!

Best regards, Horst

xyz · « **Reply #6365 on:** July 25, 2020, 04:31:29 pm »

Hi,

I followed your instructions but when I ran the command, I get the following error (towards the end of an otherwise successful run):

Code: [Select]

Reading | ################################################## | 100% 0.02s

avrdude: verifying ...
avrdude: 1 bytes of hfuse verified
avrdude: reading input file "0x04"
avrdude: writing efuse (1 bytes):

Writing |                                                    | 0% 0.00s ***failed;
Writing | ################################################## | 100% 0.05s

avrdude: 1 bytes of efuse written
avrdude: verifying efuse memory against 0x04:
avrdude: load data efuse data from input file 0x04:
avrdude: input file 0x04 contains 1 bytes
avrdude: reading on-chip efuse data:

Reading | ################################################## | 100% 0.02s

avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x0000
         0xfc != 0x04
avrdude: verification error; content mismatch

avrdude: safemode: efuse changed! Was 4, and is now fc
Would you like this fuse to be changed back? [y/n] Y

Any idea why it is complaining of mismatch and how to resolve this?

Thanks

timelessbeing · « **Reply #6366 on:** July 25, 2020, 06:11:59 pm »

@ xyz
get the latest version of AVRDUDE

http://savannah.nongnu.org/bugs/?45115

de_light · « **Reply #6367 on:** August 04, 2020, 04:17:03 am »

Gift from China arrived.

Is this possible to reprogram with custom firmware? Can't see any ICSP headers anywhere.

indman · « **Reply #6368 on:** August 04, 2020, 07:06:30 am »

Yes. I think that the location of the ICSP contacts will be similar to this option in the photo. But to be sure, you need to check each connection according to the standard connection diagram for the ATMega328 processor. Where to find the firmware for your clone, I already wrote in this message
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg3088827/#msg3088827

joshto · « **Reply #6369 on:** August 04, 2020, 03:58:39 pm »

First I want to say Bravo to the authors, amazing project. I've just bought a couple of clones, TC1 specifically, modded with a 22uF low esr cap and swapped mcu with a 644pa. Flashed u4 alt firmware, compiled and flashed of course the 1.40m on it. Seems that works very well.
I've bought it mainly for selectioning jfets. It shows Idss, coherent with a manual measure, but it's the only measure it give me. An important measure for jfets is Vgs(off), there is a way to show this value?
Thanks

madires · « **Reply #6370 on:** August 04, 2020, 04:29:28 pm »

No idea, but I'll investigate if there's a way to measure Vgs(off) with the Transistortester.

de_light · « **Reply #6371 on:** August 04, 2020, 11:09:23 pm »

Thanks. The pinouts were the same. Flashed the firmware.

jellytot · « **Reply #6372 on:** August 05, 2020, 12:12:18 pm »

Quote from: indman on September 18, 2019, 02:41:52 pm

Hi!
I compiled the English firmware of m-firmware v1.37m for a clone of AY-AT(GM328A) for 3 clock rates 8,16 and 20 MHz.
Once again great gratitude of madires for its work!
The link for downloading of firmwares here in my storage
https://yadi.sk/d/yW8xa5NJgUo5z/M328Kit+TFT/Firmware/Markus Reschke/English
ATMega328 do not have enough memory any more for all options which were made by madires therefore on a photo I showed the menu of functions which were located in the processor memory.
Also I added into the storage an original firmware from a clone of LCR-TC1 which it was succeeded to read to one of participants of a forum
https://yadi.sk/d/yW8xa5NJgUo5z/LCR%20%D0%A2%D0%A1-1/Firmware/Original

Hi Indman. I tried the original tc1 firmware you linked and it does indeed work

I am curious though about U4 original firmware as the program software doesn't appear to have a read function? can it be read or backed up or is it encrypted? Thanks..

madires · « **Reply #6373 on:** August 05, 2020, 01:27:10 pm »

The "U4" MCU doesn't support reading the current firmware, only writing a new firmware is possible. It's designed that way.

joshto · « **Reply #6374 on:** August 05, 2020, 02:11:06 pm »

Quote from: madires on August 04, 2020, 04:29:28 pm

No idea, but I'll investigate if there's a way to measure Vgs(off) with the Transistortester.

In the k-firmware documentation ttester-1.13k.Bohu.pdf at page 77 there is this:

Quote

For JFET transistors often the characteristic current Idss is specified, the current in the drainwhen the gate-source voltage is 0V. Here, however, the current is given by a 680 Ω load resistance atthe source side of the JFET. The load resistor generates a reverse voltage Vgs, which is also shown.With a 470kΩ load resistor at the source side of the JFET the Source-Drain current will be nearlyzero. With this circuit we can get the Gate-Source Cutoff voltage Vgs_off exactly enough, if thevoltage remain below 5V. With this two operating points we can estimate the current Igss with thenearly quadratic characteristic curve of the current. If the estimated current Idss stay below 40mA,a additional measurement is done without a additional resistor at the source pin. With the measuredvoltage at the source pin we can compute a additional current value. Now we can compute a betterestimated current Idss with this higher current valued, the gate-source voltage and with the knownquadratic current curve, if the value of 40mAis not exeeded. Due to the symmetrical design of theJFET transistors, the drain and source can not be distinguished.

So I think it's feasible


EEVblog Main Site	EEVblog on Youtube	EEVblog on Twitter	EEVblog on Facebook	EEVblog on Odysee

Author Topic: $20 LCR ESR Transistor checker project (Read 3451773 times)

Share me