Author Topic: $20 LCR ESR Transistor checker project  (Read 3438701 times)

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Offline jakeisprobably

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Re: $20 LCR ESR Transistor checker project
« Reply #4125 on: October 19, 2017, 05:15:22 am »
@All Repair
  Thanks for sharing. I would like to see the other side of that PCB if you ever get the chance to take a pic.

It looks like they went with a weird Vref at U2. It looks like it's marked "chw."
I assume that the LM393 is for using PWM to power the LED backlight.
I don't see any input protection.
The ZIF socket for the LCD ribbon cable is a nice touch, along with an actual capacitor discharge resistor/port.
......
  On another note, attached are a few images of what I've been playing around with. While goofing around with a Aneng AN8008 I picked up a few weeks ago I decided to see how well it measures a few 1% resistors that came in a kit. I figure a cheap $25 multimeter would make an interesting way to compare a few 1% resistors with the 0.1% resistors I have. That lead me to the curiosity of how well I can match 5% resistors using this little meter.... Well... See for yourself ;)
 

Offline mauroh

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Re: $20 LCR ESR Transistor checker project
« Reply #4126 on: October 19, 2017, 08:29:15 am »
@ turbochris,
   I like the bike, but the minivan is AWESOME!!!
Compiling the firmware is actually easier then programming it.
After installing the AVR tools, you just need to download the source and type "make all -f Makefile" in the folder of your specific hardware where the Makefile is located.
karl-heinz have done a greate job providing the Makefile already configured for so many hardware variants. For the m-firmware you need to change few other parameters, but it is pretty straightforward and well ducumented by madires.
If it goes well you can change the parameters inside the Makefile (like the frequency of the chrystal) and lunch the command again.
Here you can find the step by step instruction on how to build the firmware (thank you flywheelz!!!):
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1011926/#msg1011926

@ jakeisprobably
I also bought an Aneng AN8008 and pretty happy with it!!!
I was wondering if matching the resistor will really give us better results...
As long as the resistors are  good enouth like 1% and do not drift, the self-test should take into account the small differences in the resistors and also in the ADCs of the atmega. What should be critical is just the Voltage regulator/reference.
M'I missing something? Does the matched resistors really improve precision and or accuracy or something else?

Mauro

Offline all_repair

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Re: $20 LCR ESR Transistor checker project
« Reply #4127 on: October 19, 2017, 11:56:29 am »
rrI would like to see the other side of that PCB if you ever get the chance to take a pic.
 
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Offline jakeisprobably

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Re: $20 LCR ESR Transistor checker project
« Reply #4128 on: October 19, 2017, 10:03:48 pm »
I also bought an Aneng AN8008 and pretty happy with it!!!
I was wondering if matching the resistor will really give us better results...
As long as the resistors are  good enouth like 1% and do not drift, the self-test should take into account the small differences in the resistors and also in the ADCs of the atmega. What should be critical is just the Voltage regulator/reference.
M'I missing something? Does the matched resistors really improve precision and or accuracy or something else?
Mauro
  I'm definitely a fan of this little 9999 count meter. I'd like to understand more about it but the thread on here is huge already and I don't want to get too distracted. I'm very tempted to get another AN8008 and put it in a bench enclosure though. I've already burned through 4 batteries by using the continuity and diode checker quite a bit.
  The post where Marcus replied to my questions about the resistors and tolerances is here.
   If I understand it correctly, the probing resistors are extremely important because the software has 1 value attributed to each of the two SETS of probing resistors. This means the device can't calibrate each individual probing resistor value and compensate for the difference between channels. All calculations are based around the idea that 1mA read across test point 1 can and will be 1mA if, for example you reversed the device under test and did the same test sequence again. Of course we are interested in resolution readings that are much smaller than 1mA in resolution.
  Again, IF I understand what Marcus said in the message linked above, the accuracy of the resistor value is not terribly important, the matching tolerance is the key. Basically we can pay for an extremely accurate set of resistors at 0.1% and we end up getting the tolerance we needed. The tolerance of these resistors is a byproduct of their accuracy. If the accuracy of the resistors were important, Marcus would have had a different answer to my question about temperature coefficients. -That bit of info and his reply to my question about 500ohm and 500k resistor parallel combos is where I'm basing my understanding.
  The biggest factor beginners need to understand is the difference between accuracy and tolerance. Accuracy is how close a part is to it's designated value. The only way to know accuracy is with metrology grade equipment or by paying a calibration lab to compare your junk to their super expensive stuff and tell you how wrong you are on a piece of paper and a sticker. Determining tolerance is much easier. Tolerance is determined by resolution based measurements. That one took me awhile to really understand. Hopefully it helps the next person.

  If you look at the measured specs of the resistors I posted before, the 680 1% resistors from my AY-AT clone are at 0.82% total. That's a good bit higher than 0.1% specified in the project and it is a random sample of 1 kit that in no way indicates how good or bad others' devices may be.
   If we are not worried about accuracy and understand that tolerance is key, things change. If we have the ability to measure resistors and compare tolerances at a higher resolution with repeatable results we can create our own high tolerance set. The proper way to do this would probably be with a 5.5 digit or greater resolution meter where the resolution is much better defined.
3.5 digits - 1,999 counts
3.75 digits - 3,999 counts
4.0 digits - 9,999 counts (AN8008)
4.5 digits - 19,999 counts
5.5 digits - 199,999 counts
6.5 digits - 1,999,999 counts
   If I base my measurements on a meter with a tolerance of +3 counts that means I can't trust that last digit to be repeatable. So basically my metrics I posted are total junk to the pros watching my tomfoolery. However my junk measurements have been repeatable in scale on 3 different occasions where I have measured them. The final readings may vary but the same groups of resistors are close in value, and my matched 5% resistors consistently perform far closer in total tolerence than the ones from the kit. Also the 0.1% resistors are the most consistent on multiple measurement sessions. They also show the relative accuracy of the meter as they are probably much more accurate than the meter. I'll be doing more testing soon and will show much more in a video within the next week or so. I'm filming stuff now and have the main schematic version of the tester on a breadboard.
 -Jake
 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #4129 on: October 22, 2017, 04:10:34 pm »
The new firmware 1.30m offers:
- 180° rotated output for ST7920
- bug fix for short circuit detection
- ESR measurement for caps >= 10nF (alternative option: use old method)
- bug fix in basic frequency counter when running the MCU at 20MHz
- support of extended frequency counter (ATmega 644 circuit in Karl-Heinz's documentation, input buffer and LF & HF crystal oscillators)
- option to change dot to comma as indication for a decimal fraction
. a few minor improvements
 
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Offline casinada

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Re: $20 LCR ESR Transistor checker project
« Reply #4130 on: October 23, 2017, 04:37:07 am »
 :) :-+
 

Offline indman

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Re: $20 LCR ESR Transistor checker project
« Reply #4131 on: October 24, 2017, 04:40:18 pm »
Hi, guys!
Checked work of a new firmware 1.30m from madires on the big display 2.8 inches witch ili9341 SPI https://www.aliexpress.com/item/Free-Shipping-240x320-2-8-SPI-TFT-LCD-Touch-Panel-Serial-Port-Module-with-PCB/32612779225.html?ws_ab_test=searchweb0_0,searchweb201602_2_10152_10065_10151_10068_10344_10345_10342_10343_10340_10341_10541_10540_10307_5640017_10060_10155_10154_10056_10055_10539_10054_10538_10537_10059_10536_5370017_10534_10533_100031_10099_10103_10102_10052_10053_10107_10050_10142_10051_10170_10084_10083_10080_10082_10081_5590017_10110_10111_10112_10113_10114_10312_10313_10314_10078_10079_10073-10102,searchweb201603_25,ppcSwitch_5&btsid=cf3e87a0-bb1d-4fa2-a441-cd06580bb56f&algo_expid=0b86fc84-e0b1-4517-9dde-6c151b51a8fa-11&algo_pvid=0b86fc84-e0b1-4517-9dde-6c151b51a8fa
 Connected it to DIY Kit "AY-AT"(signal data via resistors 10 kOhm).For people who badly see it is good option, a large fonts and signs, madires big respect!  :-+ It would be successful if it is possible to make signs of symbols with higher resolution of 48x48 pixels. It is clear, that in an firmware  for ATMega328 not all functions from set were located, but there is always a choice that is more necessary in work. Firmware in English(for crystal 20MHz) for big display and also files of a configuration i will attach to the message! :D
« Last Edit: October 31, 2017, 01:24:34 pm by indman »
 
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Offline imidis

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Re: $20 LCR ESR Transistor checker project
« Reply #4132 on: October 24, 2017, 05:49:38 pm »
Nice, I like it!  :)
Gone for good
 

Offline HoracioDos

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Re: $20 LCR ESR Transistor checker project
« Reply #4133 on: October 24, 2017, 06:15:08 pm »
Hello!

I've been reading this thread since last month and I'm still lost. I bought what I guess it's an AY-AT model with a 12864 display from Alice1101983. I'm looking for the latest firmware and I have no mods.

I'm aware that there are a K (trunk) and M (Markus) firmware versions but I don't know which sub version to download and if I want to download any hex file what I get is a CVS log. Is there any sticky post with upgrade instructions and built binary files?

Thanks in advance!
 

Offline stj

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Re: $20 LCR ESR Transistor checker project
« Reply #4134 on: October 24, 2017, 06:24:59 pm »
12864 displays are not colour = post a pic or link to your unit.
 

Offline HoracioDos

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Re: $20 LCR ESR Transistor checker project
« Reply #4135 on: October 24, 2017, 06:30:17 pm »
12864 displays are not colour = post a pic or link to your unit.

I know it's not colour. That was an example if I click on any hex file. Here is the pic
 

Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #4136 on: October 24, 2017, 06:36:52 pm »
It would be successful if it is possible to make signs of symbols with higher resolution of 48x48 pixels. It is clear, that in an firmware  for ATMega328 not all functions from set were located, but there is always a choice that is more necessary in work.

You can tweak the symbol's size by changing SYMBOL_RESIZE in ILI9341.c. The defaults for the ILI9341 are  SYMBOLS_32X32_HF (in config_328.h)  and "SYMBOL_RESIZE 2" (in ILI9341.c.), i.e. the displayed symbols are 64x64. You could change that to  SYMBOLS_24X24_HF and "SYMBOL_RESIZE 3" for 72x72. The lower resolution symbols need less flash memory, but they will look more pixelated.
 

Offline indman

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Re: $20 LCR ESR Transistor checker project
« Reply #4137 on: October 24, 2017, 06:52:37 pm »
madires, SYMBOL_RESIZE increases the total area of a symbol, but he doesn't improve his permission and doesn't do it more smooth and accurate? I correctly understand it?
 

Offline mauroh

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Re: $20 LCR ESR Transistor checker project
« Reply #4138 on: October 25, 2017, 08:34:04 am »
Hi Horacio,
     your hardware is usually referred as M12864 DIY Kit and the correct folder for the k-firmware is this:
https://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328_st7565_kit/

To download the hex and epp files, click on Download GNU tarball.
Then follow this post:
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1011926/#msg1011926

If you want to use a standalone programmer like the TL866, read this.
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1156375/#msg1156375

In any case don't forget the fuses
Mauro


Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #4139 on: October 25, 2017, 10:22:12 am »
madires, SYMBOL_RESIZE increases the total area of a symbol, but he doesn't improve his permission and doesn't do it more smooth and accurate? I correctly understand it?

Yes, SYMBOL_RESIZE magnifies the symbol's bitmap.
 

Offline HoracioDos

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Re: $20 LCR ESR Transistor checker project
« Reply #4140 on: October 25, 2017, 11:35:12 am »
your hardware is usually referred as M12864 DIY Kit and the correct folder for the k-firmware is this:
https://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328_st7565_kit/
Excellent! Thank you very much!!

To download the hex and epp files, click on Download GNU tarball.
:palm: If tarball were a snake I would be already dead.

If you want to use a standalone programmer like the TL866, read this.
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg1156375/#msg1156375

In any case don't forget the fuses
You have mind reading powers  :-+
 

Offline Dismounted

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Re: $20 LCR ESR Transistor checker project
« Reply #4141 on: October 26, 2017, 01:27:08 am »
My AY-AT kit arrived today and I just put together, but... it doesn't seem to work :(

If I push the rotary encoder, the screen's white backlight lights up, but that's about it - once I let go everything turns off again. Any tips on what things I should be checking?

Bought this one: http://www.ebay.com.au/itm/2017-DIY-KITS-GM328-Transistor-Tester-Diode-Cap-ESR-Volt-Freq-Meter-PWM/182586325643
 

Offline perieanuo

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Re: $20 LCR ESR Transistor checker project
« Reply #4142 on: October 26, 2017, 06:35:15 am »
My AY-AT kit arrived today and I just put together, but... it doesn't seem to work :(

If I push the rotary encoder, the screen's white backlight lights up, but that's about it - once I let go everything turns off again. Any tips on what things I should be checking?

Bought this one: http://www.ebay.com.au/itm/2017-DIY-KITS-GM328-Transistor-Tester-Diode-Cap-ESR-Volt-Freq-Meter-PWM/182586325643
Yap, program first the chip :)

Envoyé de mon HUAWEI NXT-L29 en utilisant Tapatalk

 

Offline Dismounted

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Re: $20 LCR ESR Transistor checker project
« Reply #4143 on: October 26, 2017, 08:05:13 am »
Yap, program first the chip :)

Envoyé de mon HUAWEI NXT-L29 en utilisant Tapatalk
Ahhhhh yep, that's it! I stupidly thought the chip would come pre-programmed - I guess not...

Flashed with my USBtinyISP and it all works now, thanks! :)
 

Offline indman

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Re: $20 LCR ESR Transistor checker project
« Reply #4144 on: October 26, 2017, 01:10:34 pm »
Hi, madires!
Error in case of compilation 1.30m if to include check of servo RC.  File extras.c with a line 793.
1.29m line 787 it is correct!
« Last Edit: October 26, 2017, 01:12:53 pm by indman »
 
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Offline madires

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Re: $20 LCR ESR Transistor checker project
« Reply #4145 on: October 26, 2017, 04:39:47 pm »
Yes, that's an edit error. Please change in Servo_Check()

Code: [Select]
  #define FLAG_RUN       0b00000001     /* run / otherwise end */
to
Code: [Select]
  #define RUN_FLAG       0b00000001     /* run / otherwise end */

Thanks for reporting!
 
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Offline pepe10000

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Re: $20 LCR ESR Transistor checker project
« Reply #4146 on: October 27, 2017, 11:06:19 am »
Yes, that's an edit error. Please change in Servo_Check()

Code: [Select]
  #define FLAG_RUN       0b00000001     /* run / otherwise end */
to
Code: [Select]
  #define RUN_FLAG       0b00000001     /* run / otherwise end */

Thanks for reporting!

Modification done and already compiles well.

Thank you very much.
 

Offline cape zoloh

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Re: $20 LCR ESR Transistor checker project
« Reply #4147 on: October 27, 2017, 01:06:56 pm »
Can one of these be recommended over the others? Is there a "best one" of all these variations?
 

Offline stj

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Re: $20 LCR ESR Transistor checker project
« Reply #4148 on: October 27, 2017, 02:22:24 pm »
AY-AT colour kit is the best if you want to be able to expand it or upgrade the firmware in the future.
if your just looking to use it then there is a cased unit that also tests zeners with an internal lithium battery - i think called T7?
 

Offline boffin

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Re: $20 LCR ESR Transistor checker project
« Reply #4149 on: October 28, 2017, 03:29:58 pm »
If people here are looking for the two-step simple way of having the tools for compiling, this is about as basic as you can get  (assuming you already have the Arduino suite installed on your PC)

  • Add the following to your path: C:\Program Files (x86)\Arduino\hardware\tools\avr\bin;C:\Program Files (x86)\Arduino\hardware\tools\avr\etc. ie
    PATH C:\Program Files (x86)\Arduino\hardware\tools\avr\bin;C:\Program Files (x86)\Arduino\hardware\tools\avr\etc;%PATH%
  • Download make from equation.com  http://www.equation.com/servlet/equation.cmd?fa=make and stick it in C:\Program Files (x86)\Arduino\hardware\tools\avr\bin
 
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