How short a pulse can the GPIO spin reliably detect?
The new GPIO library allows pulse detection below 1us as the pin read is actually a single instruction (62.5 ns @ 16 MHz). The major trick in the OWI slave class is actually leaving enough time after each 1-wire bit read/write to allow processing possible interrupts. Blocking for a full transaction with reset pulse and for instance SEARCH_ROM would miss several timer interrupts (for millis).
My "test rig" includes one DS18B20 module, three DS18B20 on a breadboard and an Arduino Leonardo running as an emulated DS18B20 with 25 m telephone grade cable connect. I also use this setup for the remote Arduino test. A Saleae Logic Analyzer is used to monitor the 1-wire bus.
Please put the library to the test. I welcome your feedback and improvement suggestions. BW I will be adding a 1-wire based LCD module to further demonstrate how the 1-wire slave can be used.
Cheers!