PIC16F707 Datasheet, PDF (117/284 Pages) Microchip Technology – 40/44-Pin, Flash Microcontrollers with nanoWatt XLP and mTouch™ Technology

PIC16F707/PIC16LF707
16.0 CAPACITIVE SENSING
MODULE
The capacitive sensing modules (CSM) allow for an
interaction with an end user without a mechanical
interface. In a typical application, the capacitive
sensing module is attached to a pad on a Printed
Circuit Board (PCB), which is electrically isolated from
the end user. When the end user places their finger
over the PCB pad, a capacitive load is added, causing
a frequency shift in the capacitive sensing module. The
capacitive sensing module requires software and at
least one timer resource to determine the change in
frequency. Key features of this module include:
• Analog MUX for monitoring multiple inputs
• Capacitive sensing oscillator
• Multiple Power modes
• High power range with variable voltage
references
• Multiple timer resources
TABLE 16-1: CPSOSC TIMER USAGE
Cap Sense Oscillator
Cap Sense Oscillator A
Cap Sense Oscillator B
Mode
TimerA/Software
Timer1/Software
Timer1/TimerA
TimerB/Software
Timer3/Software
Timer3/TimerB
• Software control
• Operation during sleep
• Acquire two samples simultaneously (when using
both CSM modules)
Two identical capacitive sensing modules are
implemented on the PIC16F707/PIC16LF707. The
modules are named CPSA and CPSB. The timer
module integration for both capacitive sensing modules
is shown in Table 16-1. A block diagram of the
capacitive sensing module is shown in Figure 16-1 and
Figure 16-2.
Frequency Measurement
TimerA
Timer1
Timer1
TimerB
Timer3
Timer3
Duration Control
Software
Software
TimerA
Software
Software
TimerB
 2010 Microchip Technology Inc.
Preliminary
DS41418A-page 117