FAQ within 5 min1.) Who designed the device? Markus Frejek
2.) Where can I find updated firmware?2 versions are hosted on the Deutsch Forum where the project originated.
Download the zipped tarball here3.) Who creates these files?Markus R. (m-firmware)
Karl-Heinz K. (k-firmware)
4.) What is the best device to buy?The one you build yourself using the tarball file from above.
5.) I'm too lazy and cheap to build it from scratch. What do I look for in a clone?a.) 3× 680ohm resistors @0.1% tolerance
3× 470k resistors @0.1% tolerance
b.) Low Dropout Voltage Regulator with 0.5% accuracy or better OR less accurate LDO PLUS a precision voltage reference with 0.5% accuracy or better.
c.) ATmega328 with a replaceable dip package
d.) 6 or 10 pin "In Circuit Programming" header (ISP)
6.) I'm not very smart and I get distracted by pretty things. What's with all the different screen options? What's the best one?a.) The graphics display makes the unit noticeably slower. Several screens are supported in the official firmware.
b.) Both the alphanumeric and graphics screens do the same thing unless you speak a character based language such as many languages from Asia.
7.) I'm still very confused, and I'm starting to feel impatient with you. What is the latest cheap clone I should look for? The 'names' of clones are non-existent. The latest mass produced version (2017) comes with a red PCB that is often incorrectly called a M12864 by sellers. The variation that is sold with a frequency counter and Square Wave PWM output is usually considered the 'latest pretty version.' This version reliably comes equipped with an ATmega328 and is already configured with most project accessory options. Forum members often call it "AY-AT" because this has been printed across a few variations. The easiest way to search for it online is terms like "Transistor Tester PWM" or "tester PWM."
8.) What compromises am I making with this latest clone? a.) 1% probing resistors instead of 0.1% on most kits
b.) 1% Voltage Reference instead of better than 0.5%
c.) No ISP header so you must remove the microcontroller to update the firmware.
9.) I'm too lazy to open the tarball file, and I still have a question.***Here*** is the official PDF documentation from an older tarball file from May 2017.
10.) Lol, I'm not about to read all of that... it doesn't have enough pictures. I think I'll just ask a stupid lazy question in this forum. Use search first. Then read at least the page here:
https://www.mikrocontroller.net/articles/AVR_TransistortesterThen read the last 10 pages of this thread minimum before asking the same questions from the last couple of pages.
This forum is followed regularly by Markus R, the developer of the m-firmware. He likes to help people, as do many others here. We would all like the project to continue as long as possible, so please don't waste everyone's time asking the same questions dozens of times.
Note: I think this device is too simple. I assume it must be designed by amateurs. I know just how to improve it and I can't wait to tell everyone here about it before I read the details about the project...
This project is an exercise in maximizing the potential of the ATmega microcontroller's internal hardware using a combination of C and Assembly.
The firmware developers are more than capable of designing and integrating improved hardware options. However, they are not interested in creating a project where people must continuously "buy" the latest/greatest product. They have stated, 'If/when they feel they can no longer improve the project any further through software, they may consider creating a Tester+ version.'