G120 and SSD2533 Capacitive Touch Controller

Hi guys!

I have a custom 7" LCD with basically the exact pinout of the CP7. Great, makes it easier to debug.

This display has a capacitive touch interface utilizing the SSD2533. It interfaces via the I2C port - great.

The CP7 does not use this Touch Controller as far as I understand.

Problem is, I am unsure if I interface with this chip in managed code. Or with RLP on the low level, which I’m suspecting.

It (SSD2533) needs to be initialized and touch events are passed throuch I2C, like the controller on the CP7, but I presume these transactions are in a different format
( [Touch0] [X][Y][Pressure] ) and so forth.

Where do I implement my code to transact with this controller over the I2C bus?
Do I write my low level I2C transaction and parsing code in RLP? or can I do it through managed code?

I jumped deep into this one, because eventually I would like to do VOIP with SIP packets over UDP to a server on an APN via a HSPA 3G modem… I’m going to chew rocks
aren’t I?
Ha! I’m not scared! Well maybe a little.

Any help would be greatly appreciated!


I kind of did this. I wanted to use CP7 in a non-gagdeteer environment, so I wrote touch handler myself. Basically you need to:

[ul]Capture interrupt from the controller;
Read all the touch information from your SSD2533 (I guess you’ll have to open the manual);
Do all the position/touch/gesture calculation magic (you can analyze CP7 Gadgeteer code on codeplex for a quick start)
Feed your touch events to whatever graphics library you use.[/ul]

I did everything in managed code — works totally fine :slight_smile:

Also, you can just download the CP7 code from codeplex and adapt the class to your needs (mostly the “protected virtual void OnTouchEvent(Display_CP7 sender, TouchStatus touchStatus)” function).

This is the file you may use: http://gadgeteer.codeplex.com/SourceControl/changeset/view/28532#273373


You are making me smile today!
Okay there is hope after all. I just want to make sure I’m not climbing down the wrong rabbit hole.

Thanks a million!