UM11080
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© NXP B.V. 2017. All rights reserved.
User Manual
Rev. 1.0 — 27 November 2017
9 of 12
NXP Semiconductors
LPC845 Capacitive Touch Kit
User Manual
6. Power
measurement
P2 is provided to enable supply current to the LPC845 to be measured by placing an
ammeter in line with P2 pins. By default this jumper is bypassed by a resistor (R5) which
needs to be removed in order to use an ammeter. Header P1 may be installed to measure
supply power to the LPC845 by measuring voltage drop across a 2.43 ohm resistor on the
board.
7. Other board features
This section describes other board features not detailed elsewhere in this document.
7.1 ISP booting and the ISP button
The LPC845 can be forced into ISP boot mode by holding down the ISP button (S3) and
then holding and releasing reset. The ISP button is connected via a 100 ohm resistor to
LPC845 pin PIO0_12, which is also routed to the LPCXpresso expansion connector (pin
45) and to the cathode of the red user LED. LPC845 pin PIO0_12 can be reconfigured by
software so that the button can be used by an application as a general purpose button
(refer to the LPC84x User Manual).
Fig 3.
MP Sensor Board Connector (P9)
P1_1-CAPT_X2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
P9
HEADER 2x13 RA
PIO0_15
PIO0_16
PIO0_18
PIO0_19
PIO0_20
PIO0_21
PIO0_22
PIO0_17
VCC
VCC
PIO0_30/ACMP_I5
P1_8-CAPT_Y_LOW
PIO1_9 / CAPT_YH
PIO0_23
P0_31-CAPT_X0
P1_0-CAPT_X1
P1_2-CAPT_X3
P1_3-CAPT_X4
P1_4-CAPT_X5
P1_5-CAPT_X6
P1_6-CAPT_X7
P1_7-CAPT_X8