BOARD DETAILS
Please refer to figure 2 on page 9
Power Terminal
This screw terminal strip is used to power the board. The voltage should be b8 and +20VDC. Power
should be free from switching noise and short-term fluctuations for best performance. Be sure to check for low
voltage periodically if using a battery; low voltage will cause erratic performance.
RS232 (UART) Connector
This connector provides direct communications between the E6486 and the PC. It allows full control over the
device including calibration and setups. It also allows for real-time supervision of signal, reference and
calibration information. Use a straight-through type cable (supplied) — also known as an extender cable — to
a PC. The RS232 and SPI interfaces cannot operate at the same time.
Matrix Connector
The E6486 has two headers (J2 and J3). The pinout of both ports is described in table 1 (page 7). The header
provides the X-Y scanning of the matrix electrode. X lines drive charge into the matrix, and the Y lines conduct
the charge back out. The keyboard supplied with the kit can be connected directly to J3.
Communication Port Select
The UART port can either come from the RS232 connector or from J1. This
jumper allows the user to select the source of the UART signal.
SPI / UART Direct Port
J1 header gives access to all the signals useful for communicating with the QT60486 or QT60326. The pinout
of the connector is described below:
The QT60486/QT60326 can use either SPI or UART communications modes; it cannot use both at the same
time. The part defaults to SPI mode unless it receives a byte over the UART interface. If a UART byte is
received at any time, the UART interface is enabled and the SPI interface is totally disabled until after the next
device reset.
The QT60486 datasheet contains substantial additional information on communications.
J4
UART Source
RS232
RS232 Connector
DIRECT
J1
Pin
Description
1
SPI - Data Input
2
Power; +5V
3
SPI - Clock Input
4
SPI - Data Output
5
Reset
6
Supply Ground
7
n.c.
8
n.c.
9
SPI - Data Ready
10
SPI - Slave Select
11
UART - Receive
12
UART - Transmit
13
Wake-up from sleep input / sync input
14
Status Output
J1
MISO
Vcc
SCK
MOSI
/RST
GND
n.c.
n.c.
/DRDY
/SS
Rx
Tx
WS
STATUS
