Here's a challenge for you all!

[kjennejohn]

Could you list the IC number and IC type? I can't make out the IC type from the picture.

IC1 -
IC2 -
IC3 -
etc...

Hi. It's all been done and is sitting on this page spread over a few posts, just before your excellent drawing. You'll find the chips by IC number, their type, and jumps to data sheets for all these.

Nice job, Hackable. Unfortunately, something isn't right. You say two pins on the connector go to pins 5 and 11 of IC2. These are data output pins. Those should be going to the inputs of the HC154 and the HC138. I'll explain:

The 4094, like the 5821, takes serial data in on every clock. After you've shifted in 8 bits (more in our case, since we have more than one chip), you bang the STROBE line to latch these bits into the output register. You can just pull the OE (Output Enable) line true and forget it. The old data disappears immediately to be replaced by the new data. This is true for all these serial-to-parallel chips, the 5821s and 4094s. The chip designers realized the user may want to put out a long stream of data, so they provide a pin that allows serial data to 'overflow' to the data input of the next chip in line. You pump 64 bits to fill the 5821s and 8 more to fill the 4094 (and maybe 8 more to fill the other 4094, for reasons unknown). I think some more checking will show that pins 9 or 10 (Q's and Qs, the 'overflows') of the 4094 connect to pin 2 of the first 5821 in the chain (IC6?).
Your check of the connector pins show pins 15 (OUT ENABLE) and 3 (CLOCK) of IC2 are what we'd expect. I think you need to check and see if pins 1 (STROBE) and 2 (DATA) are really hooked to the connector pins somewhere, not pins 5 and 11, which are data outputs. I believe you'll find that 7 of the 8 data outputs of the 4094 (pins 4, 5, 6, 7, 11, 12, 13 and 14) go to the seven input pins of the HC154 and HC138. Which of the 4094s this is you'll have to find out yourself.

As for performance: this means the processor has to pump 72 (or 80?) bits for every row to be displayed. And it has to do THAT 21 times to fill the display. This is a VERY busy processor, but it only has one job, and these chips can be clocked up to 5 MHz. So, while outputting the previous row, you clock the next row's worth of data in, then pump the STROBE. You'll want to update the display, say, 18 times a second. That means you'll have to refresh the data in the latches 21x18 times a second, or 378 time a second, which is a row every 2.6 millisecond. A row-display is 72 bits, for a serial data rate of 2.67mS/72, or one bit for every 3.67 uS. No problem. Piece of cake. A mere 27K-bits per second. Not even modem speed.

Enough already. Later!
kenjj

 

[hackableFM]

As Kjennejohn says I have already supplied the info on the IC's but here it is again anyway.

IC1 = HCF4094BE
IC2 = MC14106BCP
IC3 = HCF4094BE
IC4 + 5 = MC14526BCP
IC 6 - 13 = UCN5821A
IC 14 = MM74HC138N
IC 15 = MM74HC154N

I will do more checks on the possible error's I read at the connector later on tonight when I get back from work.

Thanks again to all of you! for all of your input on this.

hackableFM.

 

[Mike - K8LH]

Hi. It's all been done and is sitting on this page spread over a few posts, just before your excellent drawing. You'll find the chips by IC number, their type, and jumps to data sheets for all these.

I saw that list but thought I may have missed something because HackableFM says edge connector pin 1 goes to pin 15 on IC2 (the 14 pin MC14106B)... Then you say pins 5 and 11 on IC2 are outputs but the MC14106B Hex Schmitt Trigger Inverter data sheet shows them as inputs...

 

[kjennejohn]

Hi. My bad, I roared through the IC list and mistakenly took IC2 to be another chip. Yes, these are all inputs. That's half the gates on this chip. Since there are so many inputs to feed, they are likely using the 14106 to increase signal strength. This is a factor called "fan out": the processor's outputs may have only had one or two milliAmps of output, which wasn't enough to drive all the inputs on this board. Also, the 14106 has Schmitt inputs. This is good for dealing with slow and noisy signals. Hackable, did you mistake pin 13 for pin 15?

If you check for continuity between the pins on IC2 you may find that the outputs for these pins go to other inputs on this same chip. This would "turn the levels right side up" so as to maintain the original control levels. That is, they are inverted twice. Then again, the programmer need only keep this in mind when setting levels at the processor. If you need a low OE at the IC, then put out a high signal at the processor and the inverter turns it low.

We progress.
kenjj

 

[Milan Syrovy]

Hello. I have query, if resolve you the problem with draving SP.ACE MATRIX DISPLAY BOARD, about which yourself wrote. I have same board and I don't know how she control. Thank you. I am sorry, my English is not good.

 

[TTX]

I found a neat little display board lying around in the shed which I got from an old Bandit/Fruit machine. It was probably used to create moving pictures as you regularly see on bandits.

It has 3 rows of 12 (36!) dot matrix LED Displays on it. Each LED Display has 5 x 7 LED's segments on it (that's 35 LED's each!) The part number written on each LED Display is LTP757R, Also on this PCB are 15 IC's, 21 Transistors, and a load of resistors. There appears to be no micro controller on the board. The PCB has 1 connector/Interface, The connector has only 9 pins.

Now my question is probably one you'll laugh at but I grabbed this sometime ago thinking it might be of some use but to be hoonest although it looks to be a useful little gadget I can't think of a use for it, nor for the life of me can I even begin to think of a way to 'drive' it.

Has anyone got any idea's on what I could use it for? Novelty idea's are welcome.... If I could make it say "Merry Christmas" then change to say "Happy New Year" or something silly, Just so I can put it to some sort of use as a Xmas decoration if nothing else!

I'll be amazed if someone can come up with an idea and a simple enough driver to get this display functioning!

hackableFM.....

***EDIT*** Other markings on the PCB are "SP.ACE MATRIX DISPLAY BOARD" and ""VERSION 2 REVISION A"

Hi hackableFM,

Sorry to drag up an old thread but do you still have this display board kicking around?

This is a fantastic forum, I work as a Test Engineer and there's some really useful stuff on here!

Cheers.

 

[hackableFM]

Emmmm, as it happens I am sure it's still kicking about somewhere, I never did get round to doing anything with it so it'll still be there somewhere!

Might I ask why you are interested?

P.S. I will be away for a couple of days so you'll not get a reply for a while after this one

 

[TTX]

I would very, very much like to buy it from you if possible please! I own a fruit machine that uses these and I've been looking specifically for a Rev2A display board for several years now.

If you'd like to have some fun with it first, I've sussed out how to drive it:

Pinouts:
1. - EN DISP
2. - DATA
3. - STROBE
4. - CLOCK
5. GND
6. PWR GND
7. +5.6V LOGIC
8. PWR GND (no pin / key)
9. +VDISP
10. +VDISP


To illuminate a single line, perform the following steps:

1. Clock in 64 bits for the column selects (bits 57-60 inc. are ignored);
2. Clock in 8 bits to select a row to drive (0x0 = bottom row);
3. Clock in 8 bits to determine the row brightness (0x0 = 100%);
4. Pulse the Strobe;
5. Repeat 1-4 for the next row.


NOTES:

1) All inputs are inverted.
2) Tie ENDISP to ground or you get nothing!
3) The input order of the column data is not what you'd initially expect!
4) The logic and VDISP supplies can be from the same source.
5) Be sure to feed it at least 1 amp @ 5vdc.
6) Do not leave one row on for too long, you may blow a row transistor.
7) I've no idea what the scan frequency should be but a PIC16F960 @ 20MHz does the job nicely.


The guy who designed this board (and the rest of its control system) is one David John Powell (DJP), electronics genius of the fruit machine world. One day I hope to have a chat with him about his work!


Have fun!


My original sussing-out thread here:
Ace Space Mpu Dot Matrix Displays - Fruit-Emu

A video of my machine running:
YouTube - Castle - Crackerpot

 

[Sceadwian]

What's the other side of the board look like? That looks like a really nice display, how you get it working.

 

[TTX]

I sussed it out using a combination of a service manual, datasheet reading and track tracing. There was a bit of luck in there too! I'll be out and about for a few days, will post some pics when I get back.

 

[TTX]

Well, here are the pics of my board, just a bit later than planned!!!