Manual
User’s Manual
Scott Edwards Electronics, Inc.
1939 S. Frontage Road, Suite F, Sierra Vista, AZ 85635 USA
ph: 520-459-4802 • fax: 520-459-0623 • www.seetron.com
BPP-420 • v4.0 • 2/03 • pg 5
Hide Cursor (control-D, ASCII 4)
Hide the cursor (either type, blinking or underline).
Show Underline Cursor (control-E, ASCII 5)
Show a non-blinking underline cursor at the printing location.
Show Blinking-Block Cursor (control-F, ASCII 6)
Show a blinking block cursor at the printing location.
Bell (control-G, ASCII 7)
Pulse J4 for approximately 100 ms to beep piezo buzzer.
Backspace (control-H or backspace key, ASCII 8)
Move the cursor back one space and erase the character in that space.
Horizontal Tab (control-I or Tab key, ASCII 9)
Move the cursor forward to next multiple-of-four column.
Smart Linefeed (control-J, ASCII 10)
Move cursor down one line. If immediately preceded by carriage return, linefeed is ignored.
Vertical Tab (control-K, ASCII 11)
Move cursor up one line.
Clear Screen (control-L, ASCII 12)
Clear the screen, leaving the cursor in position 0 (see figure 3).
Carriage Return (control-M, ASCII 13)
Move the cursor to the first position of the next line.
Backlight ON (control-N, ASCII 14)
Turn on the LED backlight.
Backlight OFF (control-O, ASCII 15)
Turn off the LED backlight.
Position Cursor (control-P, ASCII 16)
Accept a number (0 to 79) and move the cursor to that position (where 0 is the 1st character of the 1st line
and 79 is the last character of the 4th line; see figure 3). Number may be in text or single-byte format:
Text method: Send the desired display position as a printable text. For example, to move the cursor to
position 21 (2nd character, 2nd line) from a terminal program, press control-P, and type “21” followed by
a space or other character (which will be discarded).
One-byte method: Send the display position as a single-byte value equal to the position plus 64. For example,
to move to position 21 you would send control-P (ASCII 16) followed by ASCII 85 (21 + 64).
Clear Column (control-Q, ASCII 17)
Clear the current column and advance the cursor to the next column, same line. This feature can be used
to clear a four-line-high section of the screen.
Figure 3. Layout of the 4x20 LCD
0
20
40
60
1 2 3 4 ...
19
39
59
79