At 06:13 AM 9/22/2012, alan.b.pearce@stfc.ac.uk wrote: >The other thing that wasn't clear to me was are you looking at a=20 >display you can use as a touch screen? You mentioned the possibility=20 >of 'eye candy' in the form of menus, and it wasn't clear if you were=20 >looking at the possibility of a graphics touch screen where there=20 >could be scroll bars or up/down arrows. Naw - I don't want to go as fancy as a graphical touch-screen. What=20 I meant by 'eye candy' was a simple menu system, as opposed to a bare=20 display consisting of 3- seven segment displays and 5 buttons (one=20 button each for fan, heat, cool and two more buttons for up and down). My standard LCD interface uses 6 I/O lines and the four data lines=20 are also used for the four pushbuttons that I use for navigating the=20 menu. Its trivial to add a 5th button if needed (the RS bit) and=20 only slightly more complicated to expand to 8 buttons if truly needed=20 (the RS line drives a SIP resistor network that feeds pairs of=20 buttons (all with appropriate isolation resistors). The other sides=20 of the pairs of buttons tie hard to Vdd and Vss. The buttons are=20 scanned with the RS line HI, then LO. The scans are compared: if=20 bits in both scans are the same (either HI or LO), it means that=20 particular button pair is active. Easy and trivial to do! dwayne --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .