I just begin on Raspberry PI2 one week ago and as a GPIO beginner I have hard time trying to select a good nodejs library for gpio. I tried "onoff" and others which read/write to /sys/class/gpio/ files. Then, trying to understand how gpio works in details (for instance why in some tutorials of Sunfounder the led is connected to 3.3V pin and in other tutorials the 3.3V is provided by gpio pin), I encountered this excellent benchmarking article http://codeandlife.com/2012/07/03/benchmarking-raspberry-pi-gpio-speed/
. So two questions: (1) are Raspi.js and raspi-gpio written in C so results would be compared to native C or C with BCM2835 library benchmarks? (2) help me understand the tutorials differences of connecting a led to +3.3V and gpio pins, versus to ground and gpio: is that related to PULL_DOWN and PULL_UP configuration of gpio pin? Thanks!