4 Hardware Peripherals

Kit hardware peripherals overview.

4.1 LED

One yellow user LED is available on the PIC32CM PL10 Curiosity Nano board. It can be controlled by either GPIO or PWM. Driving the connected I/O line to GND will activate the LED.

Figure 4-1 4-2 4-5. PIC32CM PL10 Curiosity Nano LED0 Block Diagram
Table 4-1 4-2 4-4. LED Connection
MCU PinDescriptionDefault Connection
PB02User LED (yellow), active low
  • LED0
  • Edge connector

4.2 Mechanical Switch

The PIC32CM PL10 Curiosity Nano board has one mechanical switch - a generic, user-configurable switch. Pressing it connects the I/O pin to ground (GND).

Figure 4-1 4-2 4-5. PIC32CM PL10 Curiosity Nano SW0 Block Diagram
Tip: There is no externally connected pull-up resistor on the switch. Enable the internal pull-up resistor on Pin PB03 to use it.
Table 4-1 4-2 4-4. Mechanical Switch Connection
MCU PinDescriptionDefault Connection
PB03User switch (SW0), supports DGI event monitoring

4.3 Crystal

The PIC32CM PL10 Curiosity Nano Board has a 32.768 kHz crystal mounted. The crystal is not connected to the target MCU by default, as the GPIO pins are routed to the edge connector.

Figure 4-3. 32.768 kHz Crystal Block Diagram
Info: The 32.768 kHz crystal on the PIC32CM PL10 Curiosity Nano is included for use and testing with the PIC32CM6408PL10048 External 32.768 kHz Oscillator (XOSC32K) configured in High-Power mode.
Table 4-3. Crystal Connections
MCU PinDescriptionDefault Connection
PA24Crystal output, XTAL32K1Edge connector
PA25Crystal input, XTAL32K2
Warning: Always disconnect the board from all power sources before making any hardware modifications.
How to Connect the Crystal to the Target MCU
  1. Disconnect the two I/O lines routed to the edge connector by cutting the two cut straps on the bottom side of the board, J107 and J108.
  2. Connect the two I/O lines to the crystal by soldering a blob on each circular solder point on the top of the board (J109 and J110).
Figure 4-4. 32.768 kHz Crystal Overview
Info: The 0Ω series resistor, R111, may be replaced with any suitable resistor to limit the drive strength of the crystals. If no resistor is required, leave the resistor in place.

The 32.768 kHz crystal has a cut strap (J111), which can be used to measure the oscillator safety factor. This is done by cutting the strap and adding a 0402 SMD resistor across it. The AN2648 application note from Microchip contains more information about oscillator allowance and safety factors.

4.4 Touch Button

The PIC32CM PL10 Curiosity Nano board has a single capacitive touch button with an active shield. For details on configuration and usage, refer to the Peripheral Touch Controller (PTC) chapter in the PIC32CM PL10 device data sheet.

Figure 4-1 4-2 4-5. PIC32CM PL10 Curiosity Nano Touch Button Block Diagram
Tip: Generate the code with the capacitive touch library in MPLAB® Harmony and visualize touch sensor data in MPLAB® Data Visualizer.
Table 4-1 4-2 4-4. Capacitive Touch Button Connection
MCU PinDescriptionDefault Connection
PB08Shield connection for improved noise immunity
  • Touch button shield
  • Edge connector (disconnected by default)
PB09Capacitive touch connection
  • Touch button sensor
  • Edge connector (disconnected by default)
Warning: Always disconnect the board from all power sources before making any hardware modifications.
By default, the touch lines are not connected to the edge connector. PB08 and/or PB09 can be repurposed for other functions by connecting them to the edge connector through soldering the corresponding pads (J113 and J114) located on the bottom of the board.
Important: This modification will affect the touch button’s performance and may cause it to not function as intended.
Figure 4-6. Touch I/O Line Solder Points

4.5 Multi-Voltage I/O

The target MCU includes a Multi-Voltage I/O (MVIO) domain powered through the VDDIO2 pin. Pins PA08–PA15 are exclusively powered by VDDIO2. If VDDIO2 is not supplied, these I/O pins will not operate.

On the PIC32CM PL10 Curiosity Nano board, VCC_TARGET supplies VDDIO2 by default. Removing the 0Ω resistor R110 disconnects the default power connection. After the removal, an external power supply can power the MVIO pins through the 1x2-100mil footprint (J112).

Warning:
  • Always disconnect the board from all power sources before making changes
  • To prevent damage to the board, remove R110 before applying external voltage to VDDIO2
  • The MVIO circuit lacks reverse polarity protection. Incorrect connections at J112 may permanently damage the board.
Figure 4-7. MVIO Block Diagram
Figure 4-8. VDDIO2 Connections