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PITA VFD 20x2 Displays ..interfacing Headaches.. help ?


Artesia

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disp2.jpgdisp1.jpg

Just dug the sods at the top of this pic back out of the box,

Havng alot of trouble working out how to Interface them to anything whatsoever... Anyone able to offer any help ?

They Are some 40x2 VFD (floursecent) displays made by a spanish company called telesincro ..model no 209000211/b.

the whole thing is self sufficent on 5v ...and powers up with a quick blink of the backlight & with a cursory attempt to spit serial data at it ..i cant get anything to pop up.

Im guessing at a chance that it might use a standard protocol ..tho im somewhat baffled & ill informed web-wise...

the interface consists of:

1 ? | t1out

2 gnd |

3 ? | r1in

4 ? | r2in

5 ? | t2out

6 +ve  | 5V ?

7 gnd  |

8 +ve ? |

With the above data pins connected to the repective labeled pins of a max232 serial interface chip.

this is in turn connected to a philips 80c31bh-3 microcontroller, which has a 74hc373t & 27c256 EEPROM in its vincinity; followed by VFD Line driver chips OKI C1162 & C1163 (and a bunch of ancilliary circuitary to provide VFD Power supply etc)

Any ideas ? ...or even a driver chip that can be connected to the c1162 & 1163's ? ....as got three of these huge displays ...and it'd be a shame to waste them !

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I would first ask telesincro if they can provide a datasheet. Perhaps you can manage to print some characters without it, but you´ll definitely need to know the escape codes for cursor positioning and clearing the display.

Is there a max232 on the display? because most VFDs I´ve seen (in reality or as a datasheet) have just normal TTL levels, so if there isn´t some 232 onboard I wouldn´t connect one to the inputs to not damage the display.

Can you describe with more detail which pin of the VFD you connected to what?

Another hint: the usual serial vfds mostly have very low data rates, that are often fixed or selectable through a jumper. Probably it runs with 1200 or 2400 baud - if you´re very lucky perhaps it can do 9600 baud. This will also bring preformance issues to MIOS-based projects.

Seppoman

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Hi,

iv'e tried to get a response out of http://www.telesincro.es/ several times. However they are a big telecoms / network hardware company ..and dont seem to be all that interested in questions which wont sell new products. Never get a response back.

My guess is that the displays where an internal short run designed to cut the overall project costs on building a specific line of items & its not usually their lne of work.

There is indeeed a max232 on the display between the port and the microprocessor; the exact pin names on the chip are written on the connector pint out list in the first post.

As for connecting it, there are two sepperate max232 buffered ins and outs fully connected to the user port. i took a pot luck guess that at least one of those ins would actually listen to serial data at a number of low rates tried.. which turned out to be unfruitious.

Given that weird configuration, im guessing that the interface is for a totally custom data display solution whereby the original hardware talks bidirectionally to the display pic ...spitting up specific data.

As far as i can figure, the nearest point which a sensible connection could be gleaned, is by connecting a suitable driver chip to the OKI c1162 a c1163 VFD Line driver chips ...which accept 'serial' data and dump it in a 'tram line' fashon to the display.

Connection speed isnt a huge issue, i just want to make a big, bright display for throwing up Cue's & lyirc prompts on stage... a standard lcd is a little too small and 'dim' at times for this.

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This data sheet is NOT the right one, but does give a few examples. I've used these in Point of Sale terminal work, and whilst there does seem to be a wide range of devices, they tended to use similar command sets. The I2C ones could be more varied.

http://www.bipom.com/lcds/manuals/vk202-25.pdf

If a couple of your IO pins are equivalent to RTS and CTS, then linking them together might be a start on finding out which are RXD and TXD. It will have to use some kind of flow control.

It can be a hard slog working through all the permutations of baud rate, start and stop bits and pinout. Been there, done that, and if you look closely at the picture on the T-shirt......

Long shot: have you any info on the equipment they came out of? That might at least cut down the connection problems.

At least you can use long simple leads on stage with them Quite a cool idea, an electronic cue sheet/set list. Now I suppose you could always do  a text to speech for the drummer.

Mike

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