LPCXpresso Base Board rev B - User’s Guide
Page 42
Copyright 2011 © Embedded Artists AB
4.6
Direct Digital IO
The LPC1xxx is connected to a number of peripherals directly via the general purpose digital
input/output pins:
5-key joystick), see schematic page 6, SW2. Directly connected to GPIO_8, GPIO_9,
GPIO_10, GPIO_31 and GPIO_32
Push button (BL), see schematic page 6, SW3. See subsection 4.6.1
Push button (Wakeup), see schematic page 6, SW4. Directly connected to GPIO_16-
WAKEUP. See subsection 4.6.2
Quadrature rotary switch, see schematic page 6, SW5. See subsection 4.6.3
Temperature sensor, see schematic page 6, U7. See subsection 4.6.4
4.6.1
Push Button (BL) – SW3
See Figure 22 on page 28 for J13 settings
(schematic page 5). A jumper must be inserted
in J13, pin 1-2 in order to connect the signal
from SW3 to GPIO_24-BL_EN (which is the
bootloader enable pin for most LPC1xxx
MCU:s).
The LPC176x use another bootloader enable
pin (P2.10, which is the GPIO_37 signal on the
LPCXpresso Base Board
). Use J62 to select
where to connect the BL-button, SW3. See
Figure 43 for how to set jumper.
Figure 43 – Jumper Setting: J62 and BL-button
4.6.2
Push Button (WAKEUP) – SW4
GPIO_16-WAKEUP are can be driven from both SW4 and from the BNC Analog Input (U8) via
J28.Note that J28 must not be inserted when SW4 is to be used. See Figure 50 for details where to
find J28 (upper left side of the picture).
4.6.3
Quadrature Rotary Switch – SW5
Insert both jumpers in J56 (schematic page 6),
as illustrated in Figure 44. This will connect the
two signals (QA and QB) to GPIO_12 and
GPIO_13, respectively.
Figure 44 – Jumper Setting: Quadrature Rotary Switch, J56
Upper pos.: BL-button to GPIO_37 (which is P2.10 on
the LPC176x)
Lower pos.: BL-button to BL_EN (GPIO_24-BL_EN)
