Datasheet

The Demonstration Application
 2013 Microchip Technology Inc. DS50002172A-page 23
2.3 OTHER HARDWARE RESOURCES ON THE STARTER KIT
Connector, J2, is configured as a USB host. As it is connected in parallel with the USB
device port connector, J2 cannot be used while J3 is in use.
A footprint (R5) is provided on the board for an add-on thermistor. The footprint is
designed to accommodate an NTC thermistor in an 0805 package size. Typical values
are 10 kΩ and 47 kΩ. The CTMU can source a current to the NTC and read the result-
ing voltage using the 12-bit Pipeline A/D Converter. This feature is not implemented in
the supplied demo software. For more information, refer to Microchip Application Note,
AN1375, “See What You Can Do with the CTMU” (DS01375).
If touch sensing is not desired, the function of the touch pads can be replaced with
push button (or other momentary contact) switches. Spaces are provided for switches,
S3, S4 and S5, as well as corresponding (unpopulated) pull-up resistors, R12, R52 and
R54. Note that installing these components does not automatically disable touch sense
functionality.
The footprint for U2 has been designed to directly solder mount one of Microchip
Technology’s wireless transceiver modules. Although the MRF24J40A (2.4 GHz,
IEEE 802.15.4) wireless transceiver is specified elsewhere in this manual, in theory,
any pin-compatible Microchip wireless transceiver module can be used.
The unpopulated footprints for J1 and J5 are provided in the event that additional pro-
gramming and emulation interfaces are required. J1 provides a 6-pin interface to the
Starter Kit for use as a ICSP™ compatible emulator product (Microchip MPLAB ICD 3
programmer, the PICkit 3 programmer or the MPLAB REAL ICE emulator). It can also
be used as an alternative method for directly programming the PIC2FJ128GC010
microcontroller via In-Circuit Serial Programming™ (ICSP™). J5 provides a standard
5/6-pin interface to the PKOB and can be used to update its firmware.