Capacitive VS Resistive Displays

I’m starting a new project. On the board I’ve placed a GXP header to connect a display. Can someone help me choose which display to use. I’ve never worked with I2C at all to be completely honest so I’m a little cautious about choosing the Capacitive Display. I also intend on exposing the I2C for expansion. Which may rule out the Capacitive display if it is acting as the master[I doubt] but that’s why I’m asking the question. Which display would you choose.


I2C is dead simple and there’s sample code available. The real question is what you want to use to register the touch as different objects work better with cap/resistive.

I don’t understand what you mean sorry?

Do you want to press really big items on the screen (or the whole screen) with your finger, or do you want to press small items with high accuracy using a stylus?

Ohhh! Yeah, finger for sure. Maybe even through very thin latex rubber gloves if possible?

then you want capacitive :slight_smile:

Resistive requires a much firmer press to be detected

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You can easily share the I2C bus with other devices. Just use a lock object. I scan a number of ADC’s on I2C and when touch is detected through an interrupt, it read the touch. Works fine.

You could of course use the software I2C to do the touch as it doesn’t need to be polled fast and keep the hardware one for your other use.

I’ve found that the polled resistive with the NETMF drivers is sometimes unresponsive depending on the system load. With the cap touch I have no such issues and it works very quickly, especially with the G400 modules. G120 is fine too if just a little sluggish and more down to the graphics speed.

Capacitive it is then. Thanks for all the help everyone.

BTW, Dave, sent you an email.

does capacitive work through gloves ?

I can’t wait to find out. In my case very thin gloves. And it is not critical. just preferable.

capacitive is much better at detecting “closeness” of objects than resistive. I think you’ll get better gloved response with capacitive, but probably depends on the gloves and the touch screen. @ Dave McL does one of your Newhavens have captouch?

Brett, I use 3 different sizes from Newhaven. 4.3, 5.0 and 7.0 and all of them are capacitive touch.

Resistive touch doesn’t detect “closeness” at all; it requires a physical deformation to register a touch. Interesting discussion of nitrile gloves and cap touch screens over at EE stackexchange, here: touchscreen - Nitrile and touch screens. What is the distance required from your finger to the screen to make it work? - Electrical Engineering Stack Exchange

Browsing through, though, I’d think you’re probably fine, but test first before committing.

I’ve just ordered the capacitive display. I’ll post an update when it comes in and I test it.

whip on some gloves and start pressing for us, can you ? :slight_smile: Do the washing up if you need to get in the mood :whistle: .

I’ve tried with thick industrial type surgical gloves and they work.

My thick winter ones (for my trips to Bathurst) don’t work but the polkadot industrial ones still work.

All tested on the 7" LCD. I’ll try and test on the others later.

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