Arduino (ATmega328) Direct Register Manipulation for Custom PWM Output (ex: 1us HIGH followed by 99us LOW --> 1% Duty Cycle at 10kHz)

Here's a quick example of how to make a hardware-based 1us HIGH pulse followed by a 99us LOW pulse (ie: 100us period, or 10kHz, PWM with a 1% duty cycle), via direct timer register manipulation. I've left ample comments for you to read and follow. This example below is therefore quite easy to follow and learn from, but just as it took me dozens of hours originally to learn how to do all this stuff from scratch--and to learn about all the different PWM modes possible as described in the datasheet and elsewhere, expect to spend at least a few hours if you are truly going to read the references and dig into it enough to understand it yourself. Good luck and have fun!

References to Study:

1. Secrets of Arduino PWM, by Ken Shirriff
2. ATmega328 Datasheet (660 pg version from 11/2015)
3. ATmega168/328-Arduino Pin Mapping

Here's some oscilloscope screenshots of the output on Pin 3 produced by an Arduino Nano running the code below.

Rising edge to rising edge: Δx = 100us

Arduino PPM Reader Code - to read the signal coming out of the back of an RC transmitter!

By Gabriel Staples Written: 14 Feb. 2014
Last Updated: 14 Feb. 2014

...THIS IS A WORK IN PROGRESS...Code is finished, just tweaking and properly documenting it...
ARTICLE COMING SOON


Related Articles:

• Arduino micros() function with 0.5us precision - using my Timer2_Counter "Library"
• Beginner RC Airplane Setup
• Thunder AC680/AC6 Charger & Computer Data-Logging Software
• Parallel Charging Your LiPo Batteries

Begin article here...

Arduino micros() function with 0.5us precision - using my Timer2_Counter Library

...merging the world of Arduino and Radio Control, one tool at a time...
...CODE FOR A PRECISE MICROS() FUNCTION IS POSTED BELOW...

"I wrote a libary to get 0.5us precision on a "micros()" replacement function, so that I can get repeatable results reading a PWM or PPM signal, to within 1us.  I searched all around the internet and could not find something comparable (or that was easy to use, and maintained the Arduino's ability to write PWM signals via the Servo Libary), so I think this is my first real contribution to the world of Arduino and Radio Control."  

(font above is type "standard," from here)

Download this library:

Download eRCaGuy_Timer2_Counter

• Click the above link, optionally donate (just set the price you want to pay to $0 if you like), & download the library. You may also click here, then choose the appropriate download. 
• For the email address field, you may enter none@gmail.com if you like. Or, enter your real email if you want to receive an email with the download link, and if you don't mind if I send you an occasional email with something I'm working on (perhaps a few times a year or so).
• Install the library into the Arduino IDE (using Sketch --> Include Library --> Add .ZIP Library), then run the examples to see how to use the library.
• GitHub: https://github.com/ElectricRCAircraftGuy/eRCaGuy_TimerCounter