Power Connector
This screw terminal strip is used to power the board. The voltage should be between +8
and +20 volts DC. Power should be free from switching noise and short-term fluctuations
for best performance.
SPI Port
This connector provides all signals needed to communicate directly to the QT60xx5
through the SPI lines. Two modes of SPI are possible: Master-Slave and Slave-only,
depending on the setting of jumper J7.
A substantial section on QT60645 communications protocol is included in the QT60xx5
datasheet that is not repeated in this operation guide.
RS232 DB9 Connector
This connector provides communications between the E664 and the PC. It allows full
control over the device including calibration and Setups. It also allows for real-time super-
vising of signal, reference and calibration information. The RS232 communications takes
place via a converter processor that converts from SPI to RS232 in both directions.
Matrix Connector
This male 16-pin header provides the X-Y scan interface to the matrix electrode.
O/Pselect Jumper
This jumper allows you to switch betwen different communication modes:
RS232: The converter chip U6 will translate between RS232 and the QT60xx5’s SPI
port, enabling you to evaluate the part on a PC using QmBtn or your own software.
SPI: The QT60xx5 will be disabled, and the board provides only a translation function
which you can use to debug a QT60xx5 located on your own board. The QT60xx5 does
not communicate in this mode.
Open: Converter U6 becomes silent and all SPI lines are 3-state to allow communication
between a host and the QT60xx5 through the SPI port connector.
SPI Type Jumper
This jumper lets you select between the two SPI mode, Slave-only or Master-Slave. More
information can be found on these protocols in the QT60xx5 datasheet.
Wake/Sync Jumper
This performs two functions: Wake-up from sleep input or noise synchronization input.
For wake from sleep: Install a jumper between pins 2 and 3 to enable wake from sleep
via any serial port transmission.
For noise synchronization: Feed a TTL or 5V CMOS synchronization pulse into pin 2 of J6
with respect to GND (pin 1).
Wake from Sleep: The device can be placed into an ultra low-power sleep mode via the
setups process using QmBtn. The part will wake when a byte of data is received; the
byte is not processed and should ideally be a null byte (0x00).
For more information on these functions, see the QT60xx5 datasheet.
Noise Synchronization: Feed a 5us sync pulse (normal logic high, pulse low) to pin 2 of
J6 with respect to GND (pin 1). This will wake the part from sleep.
The QT60xx5’s bursts can be synchronized to an external source of repetitive electrical
noise, such as 50Hz or 60Hz, or possibly a buffered video display vertical sync signal,
using this feature. External noise signals to be heavily suppressed, since the system and
the noise become synchronized and no longer beat or alias with respect to each other.
The sync occurs only at the burst for key 0 (X0Y0); the device waits for the sync signal for
up to 50 ms after the end of a preceding full matrix scan (after key #63), then when a
sync pulse is received, the matrix is scanned in its entirety one time. If no sync pulse is
received in 50ms, the part wakes on its own and rescans the matrix one time then goes
Board
Details
E664/R1.0 03/02
