Touch Screen - replaced by switches

[sanramonrover]

Succeeded in building a switch bank to try to replace the now missing touch screen. Based on the original testing by hans to find which wires to the touch screen function, I ended up with a bank of 16 switches. Some wire combinations of the 8 wires do not have any effect on the display.

Got all functions of the display to work - I think! Can set and reset clock, calendar, temp, humidity, rain, etc. But I do have one button which beeps, but shows no signs of doing anything on the display.

Also not sure if the memory clear function works.

If anyone else is pursuing this engineering challenge, I can post tables and photos of progress so far.

[Gina]

Well done

[hans]

nice job,i never got to finish it,glad you did.
always to busy with other things at the same time
(right now i'm working on an automated system to feed plant furtiliser daily and weekly (2sorts) in a small shrimp tank).
in dutch and english: http://home.zonnet.nl/rsetteur/doseersp ... _spuit.htm

if you can ,post some pics and how-to for other users.
very interrested in what the connections finally are

[sanramonrover]

For those so inclined diagrams and photos of touch screen replaced by switches.
wire 1 is the bottom wire going to the touch screen foil cable (as determined by hans)


The faint circles represent the contact point of each switch.
The black dots represent a solder connection of crossed wires.

Bought 16 micro PCB mount momentary push switches - about $1 each,
Bought a piece of proto board, barely big enough - $5

Found an 8 wire miniature plug and 2 sockets scavenged from a dismantled CD player.



Attached switches in a square pattern - almost too close to each other for wiring, and large fingers!
Jumpered the socket to switches in the simplest wiring layout - but perhaps should have taken into account better switch layout.


Soldered the PCB mount pins of the other socket directly to the foil cable. After a couple of tests, the foils cracked, losing contact. Soldered real wires, using a blue ribbon cable salvaged from a computer HD connector over top of the foils.
The little white socket is now mounted firmly in a slot cut in the back of the console case.



Tested each switch function while watching the display screen. Switch #11 does not function. It beeps but doesn't seem to do anything. But perhaps that is not abnormal. I counted the touch areas on the screen and there are exactly 15. So perhaps it does not need the 16th switch.