chicken 630 Posted September 19, 2014 Share Posted September 19, 2014 Thanks to an extended road trip (6000 miles) and receiving pieces for another project in the mail (hello dAISy), I'm a bit late with starting my ESI project log. But here we go. My project is to detect touch patterns on a resistive touchscreen, e.g. to wake up or unlock a device. My idea is inspired by figure 28-19 on page 772 of the MSP430FR69xx User's Guide: The picture reminds me of the circuit for resistive touchscreens: I plan to approach the project in 3 stages of incremental functionality but also difficulty: Detecting touch while ignoring touch location. This should be pretty straight forward use of AFE, TSM and PPU. Detecting touch in a specific quadrant of the touchscreen. As the ESI does not have an ADC but only a comparator, detecting the location will have to rely one a binary search algorithm: A measured voltage indicates whether touch happened above or below (and left or right) of a specific point. This will require more complex use of the TSM, maybe even invoking the PSM. Detecting a pattern of touch events by the means of a more complex state machine. Besides unknowns about the flexibility of the PSM, I also expect challenges with debouncing touch events. All the required hardware sits on my desk, so blame any delays on procrastination. Quote Link to post Share on other sites
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