hi guys, so basically for my quad im using a Turnigy X240 along with the KK2.1 board. However for my Engineering project at school i would like to hook up a Picaxe board set with 4 PING))) Ultrasonic Distance sensors (link: https://www.parallax.com/product/28015) and use them to make the descent to land smooth. Is there a possible way to set that the reading from the Distance Sensors that the closer it gets to the ground the faster the rotors sping to slow the descent but once withing 10 cm or so the rotors cut of for the landing. preferably i would like to see me NOT require the Picaxe board but i assume it would be required because the KK wouldn't be able to. Any ideas? AMA about the project/any additional info needed. ESC's have also been changed to Afro ESC's. thanks guys, and sorry if this is in the wrong section. Just new to the forums to ask.