Microchip Technology MPLAB Starter Kit for PIC18F MCU DM180021 DM180021 Manuale Utente
Codici prodotto
DM180021
Hardware
© 2009 Microchip Technology Inc.
DS51852A-page 27
A4. BMA150 Acceleration Sensor (U6): This device implements a complete 3-axis
accelerometer and temperature sensor solution in an 8-lead QFN package. The
accelerometer is a semiconductor-based strain gauge with no moving parts and
never requires calibration. All acceleration and temperature data is provided in
real time in digital format, compatible with standard SPI interfaces.
accelerometer is a semiconductor-based strain gauge with no moving parts and
never requires calibration. All acceleration and temperature data is provided in
real time in digital format, compatible with standard SPI interfaces.
A5. Capacitive Touch Pads (S1): This 5-element keypad is an integral part of the
board’s top layer. The application responds to capacitive changes induced by
direct contact with the user by monitoring each of the touch pad’s elements with
the microcontroller’s integrated CTMU module.
direct contact with the user by monitoring each of the touch pad’s elements with
the microcontroller’s integrated CTMU module.
A6. mini-B USB Receptacle (J5): Physically identical to J1, this provides USB
connectivity for the application side when it is functioning as a peripheral device.
A7. Potentiometer (R24): Provides a variable analog input to the microcontroller for
certain demo applications.
A8. Bootloader Reset Push Button (S1): The switch provides a hardware signal
interpreted by the main application that is used to reset the application and
invoke the MicroSD bootloader.
invoke the MicroSD bootloader.
A9. OLED Voltage Boost Circuitry: L3, D5 and Q4 (along with other passive
components) are connected in a voltage boost topology. This provides the
OLED display with its nominal operating voltage of 13 V
OLED display with its nominal operating voltage of 13 V
DC
.
A10. Soft Start Circuit: Transistor Q1 and its associated passive components form a
PWM controlled regulator. This is used to keep the non-microcontroller portions
of the application within the Inrush and Suspend Current limitations spelled out in
the USB specification. See Appendix B. “USB Current Draw Requirements”
for more information.
of the application within the Inrush and Suspend Current limitations spelled out in
the USB specification. See Appendix B. “USB Current Draw Requirements”
for more information.
A11. MCP1727 Voltage Regulator (U5): The 3.3V linear regulator regulates the USB
unregulated voltage to 3.3 volts (with respect to V
SS
) and supplies the starter kit
with system power.