Manual

User’s Manual
Scott Edwards Electronics, Inc.
1939 S. Frontage Road, Suite F, Sierra Vista, AZ 85635 USA
ph: 520-459-4802 • fax: [phone] • www.seetron.com
BPP-420 • v4.0 • 2/03 • pg 4
Null (ignored prior to buffer) cntl-@ 0
Cursor home cntl-A 1
Start big characters cntl-B 2
End big characters cntl-C 3
Hide cursor cntl-D 4
Show underline cursor cntl-E 5
Show blinking-block cursor cntl-F 6
Bell (pulse piezo-buzzer output) cntl-G 7
Backspace cntl-H 8
Horizontal tab (cursor to next multiple-of-4 column) cntl-I 9
Smart linefeed (cursor down one line) cntl-J 10
Vertical tab (cursor up one line) cntl-K 11
Formfeed (clear screen) cntl-L 12
Carriage return cntl-M 13
Backlight on cntl-N 14
Backlight off cntl-O 15
Accept cursor-position entry cntl-P 16
Format right-aligned text cntl-R 18
Begin special instruction* ESC (cntl-[) 27
Table 1. Display Control Codes
Function Code ASCII
Null (control-@, ASCII 0)
Nulls are ignored; sending a null to the display has no effect. However, unlike other unused codes, nulls
are not even stored in the display buffer. They may be used as a brief time delay whose length depends
on the baud rate: 2400 bps = 4.16 ms delay; 9600 bps = 1.04 ms.
Cursor Home (control-A, ASCII 1)
Move the cursor to the first character position of the first line.
Begin Big-character Display (control-B, ASCII 2)
Put the display into big-character display mode. In this mode, characters are displayed as four-line-tall
graphics. The display can show up to four big characters at a time. The big character set includes numbers
0—9, letters A—Z (uppercase only), and symbols period (.), hyphen (-), colon (:) and space. The display
remains in big-character mode until it receives a character other than the ones listed, or a control-C. Note
that null (ASCII 0) will not end big-character mode because it is discarded before being buffered.
The numbers and letters are four columns wide followed by one blank column; punctuation and spaces
are two columns followed by one blank column.
Tips for using big characters: Give the display approximately 10 ms to ‘draw’ the characters. If you have
used ESC-D to redefine any of the custom characters, send ESC-E 1 to reset them to defaults before
displaying large characters.
End Big-character Display (control-C, ASCII 3)
End big-character mode without otherwise affecting the display.
Control Codes and Special Feaures
Table 1 lists the BPP-420 control codes. To send control codes from a terminal program, hold down
Control and press another key. For example, to send cntl-E (underline cursor) hold down Control and
press E. To send control codes from a program, send the ASCII value as a single byte (not as a text
representation of the number). Using cntl-E as an example, send a single byte containing the value 5
(00000101 binary). Control codes not listed in the table are ignored by the BPP-420 and have no effect.
*NOTE: New (rev 4.0) custom-character instructions (ESC-D and ESC-E) begin with the Escape
character; see listings under Escape at the end of this section.