Teensy++ (AVR) PLC controller – version 1

Here it is! The AT90USB646-based homebrew programmable logic controller. It’s not quite a Simatic S7 (and it’s not even completed in most parts), but it’s a nice start. A more complete and IEC-ish environment on the development software part (among many other things) would be nicer, but… the code is (will be) here, so extend […]

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Using the MsTimer2 library on AT90USB646

In order to use the Arduino MsTimer2 library on AT90USB646 microcontroller you have to minimally modify the source code of the library. First, download the library, unpack it into the “libraries” directory of your Arduino installation (it’s a subdir of “hardware”) and open the file MsTimer2.cpp.

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Using the port F as digital I/O in Teensy++

I wanted to use the port F in Teensy++ board as ordinary digital inputs/outputs and it turned out that there is an extra step involved to ordinary DDR stuff. I’m coding using the Teensy port of core Arduino libraries to AT90USB646 chip. After checking the chip datasheet, I found that the proper port initialization includes […]

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The homebrew AVR-based PLC – the introduction

Few years ago when I was searching the net for similar projects to gather some stuff for my potential graduate thesis, there was just a plain void. On techie forums ocasionaly some excited novice popped up with greeny questions about what would take to make a PLC, etc., just to get a bunch of “smart” […]

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