--------------------------------------------------------------------- GraphLCD driver library The GU256X64-3900 driver --------------------------------------------------------------------- Description ----------- The GU256X64-3900 driver supports Noritake GU256X64-3900 VFD displays. The VFD is either operating in 8 bit-mode connected to a single PC parallel port or in serial mode connected to a single PC serial port. Wirings ------- The GU256X64-3900 driver supports the following connections on a parallel port: - Standard - Satyr Standard wiring: printerport LCD other ----------- ---------- ---------- D0 (02) DB0 (08) (DataBit 0) D1 (03) DB1 (07) (DataBit 1) D2 (04) DB2 (06) (DataBit 2) D3 (05) DB3 (05) (DataBit 3) D4 (06) DB4 (04) (DataBit 4) D5 (07) DB5 (03) (DataBit 5) D6 (08) DB6 (02) (DataBit 6) D7 (09) DB7 (01) (DataBit 7) ACK (10) RDY (12) (Display Ready) INIT (16) nWR (10) (Write) GND (18) GND (09) GND (Ground) GND (19) GND (11) GND (Ground) GND (20) GND (13) GND (Ground) GND (21) GND (14) GND (Ground) VCC (15) VCC (Power supply 5V) VCC (16) VCC (Power supply 5V) Satyr Wiring: printerport LCD other ----------- ---------- ---------- nSTRB (01) nWR (10) (Write) D0 (02) DB0 (08) (DataBit 0) D1 (03) DB1 (07) (DataBit 1) D2 (04) DB2 (06) (DataBit 2) D3 (05) DB3 (05) (DataBit 3) D4 (06) DB4 (04) (DataBit 4) D5 (07) DB5 (03) (DataBit 5) D6 (08) DB6 (02) (DataBit 6) D7 (09) DB7 (01) (DataBit 7) BUSY (11) RDY (12) (Display Ready) GND (18) GND (09) GND (Ground) GND (19) GND (11) GND (Ground) GND (20) GND (13) GND (Ground) GND (21) GND (14) GND (Ground) VCC (15) VCC (Power supply 5V) VCC (16) VCC (Power supply 5V) Note: The pin numbering may vary with other displays. The GU256X64-3900 driver supports the following connection on a serial port: serialport LCD other ---------- ---------- ---------- DCD (01) DTR (02) RxD (02) TxD (04) TxD (03) RxD (01) DTR (04) DSR (03) GND (05) GND (07) GND (Ground) DSR (06) DTR (02) VCC (06) VCC (Power supply 5V) Note: The pin numbering may vary with other displays. On display switches: SW No. Function Default ------ -------- ------- 1 Display address select Off 2 Display address select Off 3 Display address select Off 4 Display address select Off 5 Baud rate select Off 6 Command mode select Off switch DMA On/Off 7 Operating mode select Off 8 Protocol Select Off Serial access to GU256X64C-3xx0 is nearly as fast as normal parallel access but doesn't create the high system load of the parallel approach. So for me serial access is preferred over normal parallel mode. Even better is the DMA parallel mode. For DMA mode you have to switch SW6 on the display to ON. Configuration Parameters ------------------------ The GU256X64-3900 driver supports the following parameters in config file: Device Instead of using the direct output via port address (see Port), you can use the parport device (/dev/parportX). The advantage over the direct output via port address is that this works for non-root users also. But it's a little bit slower. The modules ppdev.o, parport.o and parport_pc.o must be loaded or compiled into the kernel. Port Sets the port address of the parallel port. If this parameter is not given, 0x378 is used. To use this direct output, the program that uses the driver library has to be started with user 'root'. Width Sets the horizontal size of the display. If this parameter is not given, a default value of 256 pixels is used. Height Sets the vertical size of the display. If this parameter is not given, a default value of 64 pixels is used. UpsideDown Rotates the display output by 180 degrees. This might be useful, if the LCD is mounted upside-down. Possible values: 'yes', 'no' Default value: 'no' Invert Inverts the display. Possible values: 'yes', 'no' Default value: 'no' Brightness Sets the brightness of your display's backlight. Possible values: 0 <= x <= 100) Default value: 100 AdjustTiming To get a timing that is as accurate as possible, the drivers measure the time for port commands (see: benchmark in syslog). You might decrease or increase the time to wait after port commands with this parameter. Normally, there is no need to change this parameter. Possible values: -50 <= x <= 50 Default value: 0 RefreshDisplay Normally, most of the drivers do not update the whole display, but only the areas that have changed since last update. So it might be, that some faulty pixels would stay a longer time. To avoid this, the plugin makes a complete refresh from time to time. This parameter defines how often a complete refresh will be done. e.g.: A value of 5 means, that the plugin will make a complete refresh on every 5th update. A value of 0 completely disables complete refreshs. Possible values: 0 <= x <= 50 Default value: 5 Wiring Select the type of wiring your display is connected with. Possible values: 'Standard', 'Satyr' Default value: 'Standard' Interface Select the interface your display is connnected to. Possible values: 'Parallel', 'Serial' Default value: 'Parallel' DMA Enables/disables the usage of the controller's DMA mode which increases writing speed. This only works in parallel interface mode. Possible values: 'yes', 'no' Default value: 'yes'