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G120 module with capacitive touch screen


#1

I am designing an interface (hardware) that allows connecting a Newhaven 4.3" LCD with capacitive touch screen to a G120 module. I understand the LCD signals however I am somewhat confused about the touch screen signals. The Newhaven touch screen works very much like the CP7 touch screen (i.e. I2C with INT and RST signals). My question is how the GHI premium libraries handle a capacitive touch screen (if at all). Can someone point me to documentation that explains how the GHI premium libraries handle capacitive touch screens (i.e. like the CP7 LCD)?

Regards,
Synapsys


#2

It is part of the NETMF Porting Kit it has some examples.


#3

You would take the touch data from I2C and feed it into Glide. http://www.ghielectronics.com/glide/example/5/


#4

Thanks for the response. So if I understand correctly the premiumu libraries DO NOT have a touch class. It has to be written in the application, correct? That’s okay I just wanted to make sure.

Regards,
Synapsys


#5

Correct but what do you mean but “touch class”? Each display works very differently so there will always be a driver per display, not a universal driver.


#6

That’s very true.

Regards,
Synapsys


#7

To clarify, I am talking about touch, not the graphics when I say each display needs driver.


#8

@ Gus,

I understand.

Do you have a recommended circuit for connecting a push button to the G120 RESET signal? Typically this type of signal requires a pullup resistor (10K) to 3V3, a small capacitor (0.1uf) and a switch to ground. Is this suffcient?

Regards,
Synapsys


#9

Good enough


#10

Just stumbled across these old posts when doing a search for the G120 and touch.

I have the bigger 5" LCD from Newhaven with the capacitive touch and hooked it up to a ChipworkX custom board. The display is very nice once I got the timing sorted. Apart from Glide out of memory issues, I am just starting to look at the I2C driver for the touch.

@ Synapys, I was wondering if you got the 4.3" to work yet? I am only going for 1 finger touch at present. Multi-touch can come later when I have more time to develop it.

Dave…


#11

[quote]@ Synapys, I was wondering if you got the 4.3" to work yet? I am only going for 1 finger touch at present. Multi-touch can come later when I have more time to develop it.
[/quote]

I did not get it to work on the G120 yet but I have been moving to a new house that has taken up all my time. However, I did get the cap touch to work on a custom STM32F4 based graphics board. I just followed the FT5X06 specifications using a bit-banging driver.

Regards,
Synapsys