For a 30mm x 150 mm, it is recommended to use 6x30 grid of diamond patterns. You can refer the Hardware files of CY8CKIT-041-41XX PSoC 4100S CapSense Pioneer Kit. The flex PCB design shows the touchpad layout that is recommended for best performance.
1. For a 6x30 touchpad, the GPIO required is only 36 (plus 2 pins for integrating caps if CSX is used). The recommended controller would be PSoC 4100S Plus, as it offers the latest CapSense IP and provide the necessary GPIOs required. Please note however that the CapSEnse component limits each widget to have only 16 Tx sensors so two touchpad widgets would be required.
2. Any GPIO can be used as CapSense GPIO. The limitation on some controller was due to the limitation of certain pins being unable to connect to AMUXBUS and the latest devices do not have this limitation. Any GPIO in PSoC 4100S Plus can be configured as CapSense pin.
For an example of the layout, please refer the hardware design files present along with the 041-41XX kit. CY8CKIT-041-41XX PSoC 4100S CapSense Pioneer Kit
Thanks for the reply.
I'm pretty confident that the PSoC 4100S Plus will be the best PSoC device for my purposes. Thanks for clarifying the GPIO vs. Capsense pin i/o, and another look at the capsense design guide made me go duh, I would need number of pads + 2 because of how Tx and Rx work.
I'm still noobish to all of this, but I believe the next steps are designing a schematic and PCB layout in a CAD program, then getting it manufactured, then using PSoC creator to develop firmware?
What is the best way to proceed with designing a schematic and PCB layout for a touchpad with a PSoC 4100S Plus MCU? The first roadblock I've hit is that I can't seem to find a library containing the PSoC 4100S Plus in an Eagle library.
We do not have library files in Eagle format. We have the library files for Altium, Allegro and pads. You can refer this link for details: https://www.cypress.com/cad-resources/psoc-4-cad-libraries
The same is discussed in the following thread: Best Method for Schematic & PBC Layout Design for CSX Capsense Touchpad
A thought for a library source would be ultralibrarian.com . Your part might be too new to already be there, if so they can make it for you for low cost. If its been around a while, it may be there and if so its free. Here is a link to an older PSOC 4 design that is free for download on that site. Cypress Semiconductor CY8C4125AXI-483: Symbol, Footprint, 3D STEP Model | Ultra Librarian Its worth a look and I would keep this site in the back of your mind for future need.