This is a easy software to use a Otto Robot with a touch sensor.
You can find the Otto library in https://github.com/OttoDIY/DIY/tree/master/libraries
This Otto alternates three modes
Mode 1: Otto avoid obstacles
Mode 2: Otto follow the hand
Mode 3: Otto dances!
--^-- <== Touch Sensor 12
---------------
| O O |
|---------------|
YR 3==> | | <== YL 2
---------------
|| ||
RR 5==> ----- ------ <== RL 4
|----- ------|
==> Ultrasound Sensor:
-- Trigger 8
-- Echo 9
==> Buzzer 13