📑 Attached code and Link to firmware here - https://github.com/Kazakov1988/My-Otto 

The firmware is based on V11. Suitable for the Otto Plus kit (the circuit must have a Bluetooth module, a touch button and an ultrasonic sensor HC-SR04). The firmware has removed the LED matrix control and other elements that I do not use in my Otto, so it now takes only 68% of the Arduino memory. Otto knows how to respond to your stroking (touching the upper part of the body), and live for a some time satisfied without showing your love. When the time has passed, as soon as someone appears within sight of the distance sensor, Otto will begin gesturing to ask to stroke it again. At the same time, the robot retains full Bluetooth control using the official application. Check out the comments in the firmware to change Otto's behavior and reaction as you see fit.

https://youtu.be/8XB_GGpk2u4