Electrical diagram of lever control

In this kit there are schematic diagrams and a model of the lever itself.

Electrical circuitry, resbury pie sends a signal to the microcontroller, which in turn executes the command to open/close the lid of the container.
Several variants of the scheme. 

In version 2, the servo was powered by a duplicated LM2596 power supply. This is if the load on the servo is strong.

In the 3rd variant, the LM2596 was replaced by XL4016 and the FU1 rating was increased. If the load on the servo is strong.

Otherwise, everyone is similar. 
Power and communication arduino mega goes through the USB port raspberry pi.

pins 0 and 1 (according to the scheme 17 and 18 terminals) are duplicated with a serial USB port (this is how it is arranged in hardware). That is, they can not be used in the future. Therefore, pin 2 (16 terminal) was used to control the servo drive. According to the datasheet arduino mega, this pin is equipped with PWM, that is, PWM, which allows you to control the servo.