Recent content by dallmon

doughboy, I would bet it would yield very high speeds, but not very controllable. This is for a CCD camera project, and I need to toggle 16+ clocks at that kind of speed. It is all the ATmega can do to keep up with a 2.5uS pixel time. I would like to hit 1.8uS per pixel, but I just can't do it...

Yes, Those are the two lines I pulled from the file to get 100nS cycle time. Dave

1. *portToggleRegister(14) = 1; That is quicker at 11.94MHz. 2. I'm using a constant: while (1) { digitalWriteFast(14,0); digitalWriteFast(14,1); } Dave

Just to get it all in one place, and hopefully more clear: ATMega644 @20MHz makes a square wave with a period of 100nS (50nS per half cycle, which is the instruction cycle time). Teensy3.1 port emulation makes a square wave with a period of 100nS, also 50nS per half cycle. digitalFastWrite...

Paul, I use the Teensy3.1 when I need an Arduino that is 5x faster. It's just that I want an Arduino that is 10x faster. The ATmega will do for this simple digital I/O, and I'll save the Teensy for more compute-intensive tasks, where it really shines. Thanks for everyone's time! Dave

Paul, I was really looking for something faster. The ATmega I'm using has a 50nS cycle time, which would be fine if it weren't for all of the ANDs and ORs going on to toggle bits. Thanks, Dave

Hmm. That's a different datasheet than I found elsewhere on the site. The other has no GPIO sections. That is exactly what I needed. Thanks! (The digitalWriteFast has a 50nS longer cycle time than the ATmega644 I'm trying to replace) Dave

Hi, I have a Teensy 3.1, and I have a need for digital I/O that is quite a bit faster than the Arduino digitalWrite() method. I've been through the datasheet for the MCU, and I'm just not finding anything on plain old digital I/O. Does anyone have an example of setting up and using ports for...