Need some help with VFD

I found 3 VFD displays on a fleamarket and bought then for $1 a piece. The only thing I know about them is that they were probably used in slot machines as the seller sold all kinds of stuff related to those machines.
They are 1 x 16 starburst displays, they have all 5 pins and are probably serial devices.

One is labeled 'PULSEVIEW LTD' with partnr PV0176-001-F Issue C and has 2 OKI ic's on the back.
The second one has as partnumber 31-487-001 ISS 1 and has a NEC D7538AC IC on the back.
The third one has as partnumber 31-711-001 iss 2 and has a NEC D8042GF-090 IC on the back.

Has anyone some info about them because google didn't help me out a lot? Pinouts and commands are most welcome.

Thank you

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PCXT2 years ago

I have similar display unit, based on NEC uPD7537AC, microprocessor sits under tube. Yes, it is from slot machine. Here's what I reverse-engineered:

1. Inputs are pulled up to ca. 8V. Use ULN2803 to play safely.
2. Pinout is OK, but RESET must be kept low to make it work. It is needed to draw quite much from it, use 2 or 3 pins from ULN2803.

3. Protocol. Always send: clock low, data in, clock high, clock low, next bit in, clock high etc.:

INITIALIZATION: 1111000000

All next packets consist of 4-bit preamble, 6-bit parameters and 6-bit ASCII uppercase character code (@=0, A=1 ...). They are:

1001000000xxxxxx - go to position 1, emit xxxxxx character.

1000001000xxxxxx - emit character xxxxxx, move cursor to next window. If end of tube is found, it goes to the beginning.

MAKING OWN FONT: I don't remember, it's emitting some special character code (from above alphanumeric characters) plus 16 bits, they're for 16 segments. In my unit engineers were lazy and didn't connected comma, only dot.

Good luck, if I'm not too late.

MCbx

P.S. Reverse engineering made semi-automatically with own Qt-based GA framework, webcam, Perl script and IC tester as interface.

andybiker2 years ago

These look like fruit-machine displays.

The samsung version of this is 16LF01UA3.

The controller is a clone of the old Micrel MIC10937.

Follow the datasheet for initialisation, set brightness etc (which defaults to zero) and it should work.

elektro1553 years ago

Hi

I've worked it out for the PV0176-001-F and there is five pins, from the capacitor: GND, reset/cs, data, (nope), clock, +12V. I'm not sure if these pins have the exact function as i wrote, but i managed to drive it somewhat and display letters all across the display(sending still the same byte all the time). I cannot set the uC to send it at the best frequency so as amresult there was blinking of dispalyed characters, disappearing of letters, misdisplayed lettters, byt i think i'll be able to drive it as it should be done.

You're going to be pretty well doomed to drive the things from your own hardware. The chances of you finding the communication protocol is so close to zero, you may as well do it yourself.

The processors are capable of driving fluorescent displays directly, which will be tricky these days. You need to be able to pull the segments down to -30V or so, at a very low current to do it. I'd probably use an optoisolator to level shift.
About the best you can do is google the part numbers off the driver ships on the back.
janw (author)  mpilchfamily3 years ago
I allready tried that, but the NECs are microcontrollers so I still need to know what data they want to receive and what the pinout is of the boards.