
32 Document No. 001-64846 Rev. *I Getting Started with CapSense
®
Figure 2-33. Two-Layer Stack-up of a CapSense Board
Four-layer designs are an option when board area must be minimized. PCB layout plays a very important role in
CapSense system performance. Best practices are discussed in Design Considerations.
2.9.2 Firmware Component
Firmware is a vital component of the CapSense system that processes the raw count data and makes logical
decisions. The amount of firmware development required for your application depends on which CapSense controller
family that you select.
Devices from the CapSense Express family are fully configurable either through hardware or through I
2
C and do not
require any firmware development on the CapSense controller itself. These devices are appropriate for systems
where the finger touch data is sent to a host for higher level processing; see Figure 2-34.
Figure 2-34. Example CapSense Express System Implementation
Capacitance
Measurement
(Hardware)
Decision
Logic
(Firmware)
CapSense Controller
Decision
Logic
(Firmware)
Non-CapSense
Actions
Application
Functions
Host
Sensors
Devices from the CapSense and CapSense Plus families are fully programmable. These devices allow complex
system level integration. These controllers can process the raw count data as well as perform other system functions.
See the CapSense Product Portfolio and CapSense Selector Guide for additional details. Cypress‘s PSoC Designer
accommodates firmware development in C and assembly language. See Resources for more information on this and
other tools.
Comentarios a estos manuales