Quantity   Component name
1 × Arduino Mega
1 × PHPoC Shield 2 for Arduino https://www.phpoc.com/phpoc_shield.php
2 × PHPoC 4-port Relay Board https://www.phpoc.com/expansion_board_for_phpoc_shield.php#relay_board
2 × PHPoC 4-Port Digital Input Board https://www.phpoc.com/expansion_board_for_phpoc_shield.php#photocoupler_board