VK202-25 rev. 05
2
Table of Contents
1. Introduction.............................................................................................................................. 4
1.1 What it Does ..................................................................................................................................... 4
1.2 What it Does Not Do ........................................................................................................................ 4
1.3 Keypad Interface............................................................................................................................... 4
1.4 Setup for Testing .............................................................................................................................. 4
1.5 Trying Out your VK202-25 .............................................................................................................. 5
1.6 Trying out a Keypad ......................................................................................................................... 6
1.6.1 Here's what to do: ................................................................................................................... 6
1.7 To Reset the module ........................................................................
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2. Connections............................................................................................................................. 8
2.1 Connector Pinout .............................................................................................................................. 8
2.1.1 Power and I
2
C Connections .................................................................................................... 8
2.1.2 RS-232 Communications ...................................................................................................... 10
2.2 General Purpose Outputs ................................................................................................................ 11
3. Displaying
Text ...................................................................................................................... 14
3.1 General ........................................................................................................................................... 14
3.2 The Built-In Character Font............................................................................................................ 14
3.3 Writing Text to the Display ............................................................................................................ 15
3.4 Text Commands.............................................................................................................................. 15
3.4.1 Auto line wrap on (254 67) .................................................................................................. 15
3.4.2 Auto line wrap off (254 68) ................................................................................................. 15
3.4.3 Auto scroll on (254 81) ........................................................................................................ 15
3.4.4 Auto scroll off (254 82) ....................................................................................................... 15
3.4.5 Set cursor position (254 71 [column] [row]) ........................................................................ 15
3.4.6 Send cursor home (254 72)................................................................................................... 15
3.4.7 Turn on underline cursor (254 74) ....................................................................................... 15
3.4.8 Turn off underline cursor (254 75) ...................................................................................... 16
3.4.9 Turn on block (blinking) cursor (254 83) ............................................................................ 16
3.4.10 Turn off block (blinking) cursor (254 84) ....................................................................... 16
3.4.11 Cursor left (254 76) .......................................................................................................... 16
3.4.12 Cursor right (254 77)........................................................................................................ 16
4. Keypad
Interface.................................................................................................................... 17
4.1 General ........................................................................................................................................... 17
4.2 Connections .................................................................................................................................... 17
4.3 I
2
C Interface.................................................................................................................................... 18
4.4 RS-232 Interface............................................................................................................................. 18
4.5 Keypad Commands......................................................................................................................... 18
4.5.1 Auto repeat mode on (254 126 [mode] ................................................................................ 18
4.5.2 Auto repeat mode off (254 96) (R) ....................................................................................... 19
4.5.3 Auto transmit keypresses on (254 65)................................................................................... 19
4.5.4 Auto transmit keypresses off (254 79) ................................................................................. 19
4.5.5 Clear key buffer (254 69) ..................................................................................................... 19
4.5.6 Poll keypad (254 38) ............................................................................................................ 19
4.5.7 Set debounce time (254 85 [time]) ...................................................................................... 19
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