VishmanX wrote:I want to use some Arduino shields for the project and for future ones. I want to know if I can directly connect the pi to the shields or if I need a arduino uno or such hooked to the pi.
The problem with using Arduino shields is that most of them require 5V power supply. Pi's GPIO P1 header provides the necessary 5V but the Pi GPIO pins are not 5V tolerant. If you hookup a shield that drives Pi's GPIO with voltage level above 3.3V then you have a problem and potentially damaged Pi. Now you see the reason for the bridge boards which not only adapt shield pinout but also provide voltage level translation to protect Pi GPIO.
If you have a shield that works with the 3.3V power supply then you can use it safely as long as you power it with 3.3V.
Again Pi P1 header provides the 3.3V power but it has a current limitation of about 50 mA and shield has to stay below this limit at all times.
if anyone has a cheap solution it would be great.
This "Raspberry Pi - P1 Connector DIY Kit for 20 GPIO Pins Wires" kit can be used to connect Arduino shield directly to GPIO.
Also, if this is possible recommendations for how to do the automation would be really helpful.
What exactly are you trying to automate?