Mini VFD

A small Vacuum Flourescent Display I recovered from the skip at work.

It is housed in a project box with a mains transformer - it use to have a mystery 9-pin serial port input but it wouldn't work until we worked out that it was expecting a 5V TTL serial signal.

The Futaba Corp M202SD08G module is a 20 character x 2 line, 5x8 dot matrix display. It has a European font with characters in the range from 0x20 (space) through the ASCII range and up to 0xFF with a bunch of Greek and Cyrillic characters.

• http://www.futaba.com/products/displays/app_notes/index.asp
• http://www.futaba.com/products/display_modules/module_products/character/index.asp
• http://docs-europe.origin.electrocomponents.com/webdocs/0d12/0900766b80d12d9a.pdf

I've put a Xino into the box and I'm working on something amusing for it to do in the hackspace.

The module has a single 20 pin connector (2x10 0.1" pins) of which we only need connection for +5V, GND, serial data in and a busy line out. The module asserts the busy line when it is working but it is enough to just make short delays in your code!

I have a simple Arduino sketch that just shows each character. It uses NewSoftSerial on pins 2 and 3 as well as regular serial on pins 0 and 1 (on old Arduino0022) just for testing to see if NewSoftSerial is any good.

#include <NewSoftSerial.h>
#include <icrmacros.h>

NewSoftSerial mySerial(2, 3);
void setup() 
{ 
  Serial.begin(9600);
  mySerial.begin(9600);
} 

int b = 0x20; 

void loop() 
{ 
  Serial.print(b, BYTE);
  mySerial.print(b, BYTE);
  delay(100);
  b++;
  if(b == 0xff){
    b = 0x20; // the first char in the VFD table
    delay(1000);
  }
 
}

The mains transformer in the box is this LASCAR PSU 201 Fixed Voltage Single Rail Power Supply...

• http://www.lascarelectronics.com/temperaturedatalogger.php?datalogger=126
• Quite expensive at £107: http://uk.farnell.com/lascar/psu-20105/lascar-part/dp/2083568

Although the unit is useful as a plain serial-driven ASCII display there are some interesting capabilities alluded to in the various datasheets. The VFD character table includes some programmable characters. I'd like to have a go at this! There are control sequences to shift the screen and create a scrolling effect.