Table 3-1 ASCII Command Set
ASCII
Code
s
Hex
Code
0x73
Purpose
Button State.
Returns 4 bytes of on/off status
for all buttons
Identification command.
QT60320 responds with signature
"32000xx" where xx is the code
revision
Error reporting.
Returns 4 bytes corresponding to
error bits for each key
Data Signal Reporting.
Returns signal and reference for
the key at location
X Y
Offset,Coarse Cal Reporting.
Returns coarse and offset values
for the key at location
X Y
Settings Reporting.
Returns Gain and Threshold
levels for chosen key at
A
Settings Write.
Writes the Gain or Threshold
value
v
for the chosen key at
A
Port Write.
Writes byte value
v
to the user
output pins O1..O8
Port Read.
Reads back the 4 bits of user port
pins I1..I4
multiple bits being set in the data stream. The device
supports n-key rollover to a limit of all 32 keys.
Example:
The key at intersection X5/Y2 appears at bit 4 in
the second byte; if key X5/Y2 is touched the bit is set. All
untouched bits register as a ‘0'.
3.2.2 'S' C
OMMAND
- I
DENTIFICATION
R
EPORTING
(Hex code 0x53) The E6S3 board responds with the 7-byte
ASCII signature "32000xx" where x is the code revision.
S
0x53
3.2.3 'e' C
OMMAND
- E
RROR
R
EPORTING
(Hex code 0x65) This command allows the host to retrieve
the error status bits for all buttons, in 4 consecutive bytes
(Table 3-3). The byte and bit sequences are identical to that
described in conjunction with the 's' command (see prior).
The appropriate bits are set high when errors are detected.
The error may be caused either by a short across the button
or an open circuit at the button.
e
0x65
/dXY
0x2F 0x64 X Y
/DXY
0x2F 0x44 X Y
/eA
0x2F 0x65 A
3.2.4 '/dXY' C
OMMAND
- D
ATA
S
IGNAL
R
EPORTING
(Hex codes 0x2F 0x64 X Y) This sequence reports back the
signal level and reference value for the key chosen. X and Y
are zero-referenced binary (not ASCII) values in the range
0..7 for X and 0..3 for Y to indicate the button for which data
is requested. If X=0 and Y=0, the device reports back with
the data for key X1 Y1. If X=3 and Y=1, the key selected is
X4 Y2. The last key is X8 Y4, so the highest /dXY command
is /d73 where '7' and '3' are in binary.
The device reports back with two bytes: the first is the
reference level, the second is the signal level. Both are
binary bytes of range 0..255.
/EAv
0x2F 0x45 A v
Ov
0x4F v
I
0x49
The port can be directly connected to a like port of a host
MCU, or transmitted over a length of cable on a standard
RS232C interface to a PC or other device, with the aid of a
MAX232 type driver/receiver circuit.
3.2.5 '/DXY' C
OMMAND
- O
FFSET
& C
OARSE
R
EPORTING
(Hex codes 0x2F 0x44 X Y) This sequence reports back the
fine offset (R2R DAC) and coarse (Cz1, Cz2 bucking caps)
values for the key chosen. X and Y are zero- referenced
binary (not ASCII) values in the range 0..7 for X and 0..3 for Y
to indicate the button for which data is requested.
The device reports back with two bytes: the first is the R2R
offset DAC amount (0..255), the second is the coarse setting
as a bit pattern: coarse bit 0 corresponds to Cz1, coarse bit 1
to Cz2, resulting in valid data values of 0, 1, 3.
This information is useful in observing circuit behavior for
diagnostic purposes during development. Values of Coarse =
3 and Offset > 128 indicate excessive X-to-Y coupling that
can arise due to normal production variances or component
drift. The maximum limit the circuit can tolerate is Coarse = 3,
Offset = 255 before the signal saturates and a key becomes
inoperable.
3.2 COMMAND SET
The 60320 requires ASCII commands over the serial port in
order to send result data. The commands must be one of
those listed in Table 3-1. None of the commands should ever
be terminated with a CR or LF code. Each command is
self-contained and requires no terminator.
3.2.1 's' C
OMMAND
- B
UTTON
S
TATE
(Hex code 0x73) After an ‘s’ character is received, the E6S3
reports back the touch-state of the buttons; it responds by
transmitting back 4 bytes of data containing a total of 32 data
bits, where each bit represents the state of one button (Table
3-2).
Each byte holds the state of the buttons contained in a Y
column. The first byte corresponds to column Y1 while the
4th byte corresponds to column Y4. Bit 0 of each byte holds
the state of the button corresponding to X1; bit 7 holds the
state corresponding to X8. Multiple key presses will show as
3.2.6 '/eA' C
OMMAND
- S
ETTINGS
R
EPORTING
(Hex codes 0x2F 0x65 A) Allows the gain and threshold
settings for a specific button to be read back to the host. 'A' is
a single binary byte specifying the
address of the data to be read.
Table 3-2 's' Command button state responses
Separate commands must be issued to
read the gain and threshold for each
BIT #
7
6
5
4
3
2
1
0
button as these values are held at
BYTE #
separate addresses, with the data for
the threshold being held in the address
1
X8/Y1
X7/Y1
X6/Y1
X5/Y1
X4/Y1
X3/Y1
X2/Y1
X1/Y1
immediately following that for the gain.
X8/Y2
X7/Y2
X6/Y2
X5/Y2
X4/Y2
X3/Y2
X2/Y2
X1/Y2
2
The gain and threshold settings for all
X8/Y3
X7/Y3
X6/Y3
X5/Y3
X4/Y3
X3/Y3
X2/Y3
X1/Y3
3
buttons are held in an internal byte
X8/Y4
X7/Y4
X6/Y4
X5/Y4
X4/Y4
X3/Y4
X2/Y4
X1/Y4
array, starting at address 100 (decimal).
4
LQ
7
QT60320C R1.08/01.03
QUANTUM [ QUANTUM RESEARCH GROUP ]
