Specifications
38 
last?) 
5 years for 5 Wire 
Cost 
Inexpensive 
Expensive 
Average cost 
Sensitivity 
Very sensitive to 
scratch 
Sensitive to 
scratch 
Sensitive to dirt 
Advantages 
Inexpensive, can 
detect any object, 
not sensitive to 
water, humidity or 
dust 
Can be used on 
curved surface, 
not sensitive to 
water 
Average cost, 
scratch resistant, 
not sensitive to 
humidity or 
temperature 
Disadvantages 
Sensitive to 
scratch, low 
fidelity, and 
reduce visibility of 
the touch screen 
Very expensive, 
sensitive to 
scratch 
Can only use your 
finger, reduces 
illumination, can‟t 
move your finger 
(so it can be able 
to detect it for 
position) 
Color Fidelity 
Low 
Low 
Low 
Response time 
For 4 wire: Less 
than 10 ms 
For 5 wire: Less 
than 15 ms 
10 ms 
Less than 15 ms 
Installation 
Built - in or Onwall 
Built - in or Onwall 
Built - in 
Following Speed 
Good 
Low 
Good 
Stability 
High 
Best stability out 
of all 3 
Ok 
Light Resistant 
Good 
Good 
Bad 
Table 5 Touch screen technology comparison 
Next on the list of components for a touch screen display is the controller. The 
two controller  configurations used  are  the  ISA Bus  and  the  Serial  RS232.  ISA 
Bus controllers are limited only to a printed circuit board. The serial controllers 
are built on printed circuit boards and are surface mounted using a soldering gun. 
These different types of controllers are basically PC cards that attach the touch 
sensor  to  the  PC.  It  holds  information  from  the  touch  sensor  and  relays  the 
information to the PC so it can understand it better. 
Finally the software driver is an essential part in the HVAC system control that 
we will be developing for the Efficient HVAC Control and Feedback System. The 










