LCR-T4 transistor tester original firmware

Bought cheap transistor tester from eBay and currently experimenting with firmware updates. I was able to program it with this version of Markus transistor tester firmware: https://github.com/svn2github/transistortester/tree/master/Software/trunk/mega328_T4_v2_st7565 To build, use a WinAVR programmers notepad, open Makefile and select Tools->Make all. At first, was getting weir errors, but after adding msys-1.0.dll to \WinAVR-20100110\utils\bin everything built ok. Before doing firmware experiments, I have made backup of original firmware, if somebody needs it, you can download it here: Code Data Config I tried to reflash original firmware and it worked fine. For programming…

Continue Reading

Modify Arduino 5v relay module to work from 3.3v

I am implementing a power-off function for my Ender 3 using OctoPi. For that, I need a relay and I happened to have one. Unfortunately, after connection relay to Raspberry Pi GPIO pin, the relay was always on and not listening to any commands from OctoPi. It appears this module was designed for 5v logic levels and Raspberry Pi works with 3.3v logic levels. After investigating relay one can see that its circuit is: For JC817C forward voltage Vf=1.2V and forward current If=20mA For Raspberry Pi output high (when VDD…

Continue Reading

Learning the Art of Electronics, Week 2

[latexpage]  2L1.1 Ok, I  form a simple low pass filter using unknown RC values. Then I measure time constant using scope and 500Hz square wave. Time constant is a time it takes for a voltage to reach ~63% of its total value. Measured time constant using RIGOL DS1054z is 0.268ms ( measured using manual cursors: I set Percent for Vert. Units, then Set range of the wave with vertical cursors and then measure time to rise to ~63% (bx-by) ) Measured time constant using Tektronix 2221A is 0.270ms ( I…

Continue Reading

End of content

No more pages to load

Close Menu