Images from the inside:

Software installation

Java:
sudo apt-get install openjdk-8-jre-headless -y


WiringPi:
http://wiringpi.com/

sudo apt-get install wiringpi

Pi4J:

https://pi4j.com/1.2/install.html

curl -sSL https://pi4j.com/install | sudo bash


Tss:
https://gitlab.com/stefano.falconetti/tss

PWM Servo hat and short circuit between servo power and GPIO:

https://forums.adafruit.com/viewtopic.php?f=8&t=165285&p=811358#p811358

Mapping between PCA9685 PWM i2c controller and leg segments:

PWM I2C controller pin number	Leg segment
00	A0
01	A1
02	A2
03	D3
04	D4
05	D5
06	C6
07	C8
08	C7
09	B9
10	B11
11	B10

Power voltage: 5v
Power current all legs and segments active: