The SV2000 uses 9600 baud rate and 8N1 serial protocol. Any received ASCII characters are printed on screen, except for commands that begin with the escape code (ASCII 27). When the cursor reaches the right lower corner, the existing text is scrolled up one line. On power up, the SV2000 starts with the last saved text and state.
List of commands:
Chip ignores these codes
Moves cursor to beginning of line
Delete last character
Set Cursor Position
ESC S x y
Move cursor to position X, Y
Set Cursor Home
Set cursor to 0, 0
Select Font 1
Select Font 2
Select Font 3
Show version info
Turns on the screen, set Font1, shows the welcome banner on screen
Get device ID
Returns the device ID and version number
Turn Screen on (Screen defaults to on)
Turn Screen off
Set white characters on black background (for all text)
Set black characters on white background (for all text)
Set CCIR-based mode (624 lines, 50 fps Europe)
Set RS170-based mode (524 lines, 60 fps US)
Set Vertical Position
ESC V x
Adjust vertical position of text, x=0ÃƒÂ¢Ã¢â€šÂ¬Ã‚Â¦31 lines, Defaults to 16
Save/Restore and Font Command
Save current state*
Save screen text and current state to FLASH
Restore saving state*
Restore screen text and current state from FLASH
Send data to buffer
ESC @ ...
d1...d64ÃƒÂ¢Ã¢â€šÂ¬Ã¢â‚¬Å“data, d65 is CRC (not used, any value)
Write buffer to FLASH*
ESC # x x
x-number of FLASH block from 0...143 (x is multiplied by 2)
Note. The commands marked by * require additional processing time (approx 20ms) before the next command can be sent.
Normal or Inverted Serial communications mode. (Normal=+5v, invented= gnd)
The SV2000 requires 3 external resistors (R1, R2, and R3) to create composite video from separate video and sync signals. The arrangement in the schematic below produces a 1V peak-to-peak signal. TV input impedance is usually 75 ohm which will decrease the resulting range somewhat. Some TV devices have automatic gain tuning, however adjustment of R2 or R3 may required.
RX Pin 3 is used as the serial data input. The input mode is selected by tying Pin 6 to +5v volts for normal operation or ground for inverted operation. In normal mode, the SV2000 works with any TTL source (i.e. MAX232 line driver etc.).
The SV2000 can be directly connected to a PC Com port by tying pin 6 to ground to enable inverted mode and adding additional 10k resistors on TX Pin 5 and RX Pin 3. The voltage range on pin 3 is limited by the SV2000 PC's internal protective diodes. Not all older PC's will work with this method however, it is provided to allow fast prototyping.
Note. The SV2000 has high impedance for data input (RX pin 3), so it must be connected. Provide a pull up resistor for normal mode or a pull down resistor for inverted mode) Suggested resistor values are between 100 and 1M Ohm.
The SV2000 sends character code 255 once every second to the serial output, TX Pin 5. This signal can be used to determine if the SV2000 is connected and working.
SV2000 Datasheet (word doc)