Flip Dot Display - FP2800A interface issues

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Hello Everyone,

I have a number of Ferranti Packard flip dot display boards that I am trying to interface with an Arduino Mega. The boards have 2 FP2800a ic's, one to control the rows and one to control the columns. Both chips are then interfaced with a 26 pin connector at the edge of the board.

The FP2800s are hard to find, so before I started messing with the displays themselves I took out a few of them to play with. I was able to get them to light up leds when I sent the required data to the chip (Adress, enable, e.t.c) but now that I have them back in the boards I am struggling.

The 2800s have a VCC pin and VS pin. The data sheet for the ic says that it wants 5v on VCC for logic and around 25v on VS, which then gets sent to the appropriate coils. When I set the outputs to toggle row 1, col 1, instead of seeing 25 volts on those outputs I see 5 volts. I think this issue has more to do with the 2800s and less to do with the Arduino side, but does anyone have any ideas why this would be happening? I have double checked the pin out and my connections, but I feel like I may be overlooking something simple. Thanks!

Zach

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Any datasheet available from the archives?

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You have measured 25V reach VS ?

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Thanks for posting the data sheet, it matches the one I am using. Yes, VS reads 25 volts and vcc reads 5v.

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I have a data sheet for the 2800a but not the specific display board that I am using it with. I have been able to figure out the pinout of the boards connector just by probing for continuity.

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No problem. @zwieblum just posted it.

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Hey! I just found this post. Based on your description you've got the FP 317 displays. I have a few of these as well and I have actually reverse engineered them already and wrote an Arduino library for it. You can find it on my github:

Hope this helps!

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