MSP430FR2633: MSP Capacitive Touch Sensing Enquires

Hello Alex,

I see you are interested in touchpad development and our MSP430FR2633.  Let me try to help answer your questions.

First, in case you haven't seen our Captivate Technology Design Guide, you will find most all the information you need regarding Captivate capacitive touch technology.

Here is some general information about Captivate Technology and the type of sensing capabilities.

I will advise you in advance, this would be a very challenging engineering design.  You probably have searched the internet to see if such designs exist and you probably didn't find many metal touch touchpad designs.  That's because it is difficult and expensive to manufacture.  For detailed information on how to design metal touch sensors, take a look at application note, Capacitve Touch through Metal,  slaa811. 

Let's take a look at your questions.

ALEX TAN CHIAN CHUAN said:

May i know TI do have the latest design application sample note for such MSP430FR2633 or equivalent?

If you are asking if TI has an application note specifically for touchpad, unfortunately we do not.  There is information about touchpads in the Captivate Technology Guide, Design chapter.

ALEX TAN CHIAN CHUAN said:

May i know does this MSP series for support on swipe gesture function on a DPAD like on the remote application? If yes, does it support on metal overlay on DPAD without affect swiping gesture performance? 

The Captivate software library does provide basic support for 1-finger gestures such as swipe and tap.  It is possible to add your own code to create your own gestures.  Here are some documents regarding capacitive touch gestures:

Capacitive Touch Gesture Software and Tuning, SLAA877

Reference design TIDM-02004,Gesture-Based Capacitive Touch

From experience working on metal touch sensors like buttons and sliders for appliances, I can tell you attempting to design a metal touch sensor is difficult and has many manufacturing challenges.  We have designed many touchpads, but all are on FR4 or flex PCBs with a plastic overlay, not metal.  If you go down this path I can help advise on the metal overlay mechanical design. 

ALEX TAN CHIAN CHUAN said:

I would like to have a detailed information regarding the touch pattern layout used(type of PCB pattern designs) on the touch pad/DPAD (area on where involving touch function and swipe function) by using this MSP.

There is an application note regarding touchpad sensor layout.  See Application Note SLAA891 - Automating Capacitive Touch Sensor Design using OpenSCAD Scripts.  This application note describes a software tool that can be used to automate touchpad sensor designs, making it much simpler, faster to design your touchpad.

ALEX TAN CHIAN CHUAN said:

From capacitive touch sensing details on CapTIvate Technology using MSP430 MCU series, is that possible for an application to have swipe and touch function at the same time under a metal overlay application?

I think what you are asking is if metal touch can detect a finger touch and another finger swipe at same time. That is effectively a 2-finger touch. No. Because of the flexing of the metal overlay, only one pressure point can be resolved accurately, so you are limited to single finger touch only.

Let me know if you are still interested in attempting this.  I can share additional information that may be helpful.