How to drive multiple relays with Raspberry Pi and Delphi

The recipe series on Raspberry Pi continues with the same route seen for Arduino. So, let's see how you can open and close a circuit using a Relay Module and how to make it programmable through a Delphi application.

Getting ready

The purpose of this recipe is to turn two different light bulbs ON or OFF through the use of a 2 Relay Module and make it controllable through an application written in Delphi.

In this recipe, we are going to use the following:

• Raspberry Pi 3 Model B
• 2 Channel Relay Module (http://wiki.sunfounder.cc/index.php?title=2_Channel_5V_Relay_Module)
• Two light bulbs and a relative supply power (the important thing is that the light bulbs have...