Trash Drone Router Platform

read data and calculate pid is a time dependet task. when time is removed to improve calculations you mus read in a time fixed way. in linux you can achieve this by setting signal and alert time fixed and a kernel special schedule to allow to make the process enter in cpu. this is the best way to make uniform process. faster reads can be done without this but it will not time fixed and stabilizations will be lacking

you can read a lot of pid tutorials but the best way to tune pitch and roll pid once you have the basic idea is to block the drone in pitch or roll plane and sense with your hand how drone acts when yu change pid params

la foneta acts as main brain of atropos but it needs sensors to reas attitude. i need four gpios to emulate 2 i2c ports. one of them is enough but wii motion and nunchuck together works different and i lose nunchuck precision. to control motors i need a pwm generator so I used a 16f pic frm spare projects thar receives command via serial

The very first thing we need to decide is in which platform of hardware we are going to develop our project. I decided to use routers because they are cheap an run an entire operating system. I started this project four years ago so routers was and still are a very  good way to develop. 

openwrt is one of the most popular firmware for linux embedded developers because it is very customizable. for the router choosing I choose la fonera 2201 because I need small size and at leas 4 gpios free and ethernet and serial. Four years ago it was one of the best choices