Wallbox to PC via Serial Port

[Carlito]

Hey everyone,
   First off this looks like a great board.  I'm hoping I'll be able to get some good help here.

I've read through the forum and haven't really seen anything that will help me for my specific need, so I'm hoping someone out there can.

What I'm trying to accomplish is hooking up my Seeburg 3W100 wallbox to my pc via serial port to play my music files through the pc.
I know there are commercial products available that do this, but in the interest of open source and my own curiosity I'm hoping to accomplish this myself (and of course with your help  )
What I need is some knowledge of how to physically make the connection from the wallbox to the serial cable.
Which pins to which terminals and such.  I have tried many different combinations but just haven't been able to get the pc to pick anything up.

So please, anyone with some knowledge in this area I'd be very happy to hear from you.

Thanks,
Carlito

[hng]

here's a link to a PDF for a manual for a wallbox-to-serial setup. pg15 has the connections for the seeburg... just a power and a signal. But, the power is 25volts AC... I'm assuming in the li'l black box on this adapter, it changes the voltage, to what, I'd also assume that there is a fuse in there... don't know what else though. I think the only way to get to the bottom of this is to buy one, and reverse engineer it.

http://www.datasynceng.com/download/pcp2man.pdf

http://www.cdadapter.com/pcplay.htm

I just got a rock-ola wall box and was planning on using the I-pod adapter, but if you could figure out how to this works, I'd be willing to jump on board and help with  figuring stuff out.

http://www.datasynceng.com/download/wipod.pdf

Only problem is I'll be moving in 10 days, so it will be a couple weeks before I can start messing with juke stuff. Not to mention I still have to finish my game cab.

[Carlito]

Hey, thanks for the info.
   I have seen this pdf before and was basically the reason I knew it could be hooked up to the serial port.
The problem I'm having is which pins in the serial port do those 2 wires hook up to? and what (if anything) is in the black box?

[hng]

My guess is the "black box" contains a Transformer to go from 25V AC to somewhere between 1 and 5V DC. Probably also has a fuse to protect the computer.

As far as what pins to hook up to on the serial end, my GUESS would be it doesn't matter. In the software you just tell the computer which pins to monitor.

I'm assuming that the Wall Box is acting like a switch, just sending a pulse signal, like morse code.

wait.. that doesn't make sense... if that was the case, the voltage would be supplied by the computer. Now I'm thinking that the 25V AC feed is being used to power whatever is in the "black box".

hmmm... it would probably help if we knew how many wires were going into the computer.

Lets assume the hardware part of this could be figured out... what about software?

[Carlito]

Software wise I have a couple linux bash scripts set up that should do the job.
When I finally find a way to hook this up to the pc I will write a script that reads the pulses and writes the time of each pulse to a file.
Then I have a script set up that will read the timings to determine which song was selected.  Then I map the song to a filename and play through a commandline mp3 player.

Everything is working nicely.  Well....except for the whole 'can't hook the wallbox to the pc' thing 

[BobA]

I think that since the original wall box controlled a stepping relay it is logical to assume that the black box is there to convert that signal to one the RS 232 port will recognize.  In the box the signal could be controlling a small relay that closes contacts across a pin and ground on the RS-232 port that is sensed by the Wallbox to PC program.  If you look up a serial port you will see that there are specific pins such as DTR or RTS etc that can be monitored.  These were often used for simple data input to a PC. You are probably not converting the pulses to anything in the box as it is simpler to let the program poll a pin and determine what the pulse stream is.

So don't look for an RS232 signal.  Just look for the toggling of a data bit on the port.  When you find what pin changes then you can work out how to decode the pulse stream.

Just a guess 

Edit: Added RTS

[hng]

So don't look for an RS232 signal.  Just look for the toggling of a data bit on the port.  When you find what pin changes then you can work out how to decode the pulse stream.

Just a guess 

Edit: Added RTS

Yup... from my understanding, the "signal" wire from the wall-box just sends out pulses... like reading a check engine light on late80's /early 90's cars... first set of flashes for  100's, then 10's, then 1's. So if you punched up 361, you'd get  "***pause******pause*"

From the pic in the PPDF I linked, it shows 2 wires coming from the wallbox. One is the Signal wire, and one is 24V AC. My question is how do I convert this to something the computer can: a)safely receive and b)read?

I guess it would help if I knew what was coming on the signal wire, but I haven't powered my wallbox up yet. I was going to wait till after I moved, but since today suddenly became my last day at my old job, I seem to have a lil bit extra time.

[BobA]

From the pic in the PPDF I linked, it shows 2 wires coming from the wallbox. One is the Signal wire, and one is 24V AC. My question is how do I convert this to something the computer can: a)safely receive and b)read?

Use a 24 VAC relay and onlly feed the contact closure to your RS-232 port.

To read it you need a program that can read the status bits on the RS-232 port and convert to meaningful info.  Probably what the wallbox to PC people are selling.

[hng]

so...

all I need in the "black box" is a 24V relay?  Don't I need to step the voltage down to something in the 1-2 volt range?


wait... I tried drawing it up, and I see whats going on... I have 24V and signal(ground) on the wall box side of the realy. They are being used to close (modulate) the relay. On the computer side of the relay, I'll have a voltage (whatever it is... 1,2,5 Vdc) and a ground.

I'm used to working on systems that are just 12volts, and use only a 3wire hookup,  so it didn't even dawn on me that the "two sides" would be isolated.

Jesus... if that's right, than that is freaking easy.

so now all thats needed is to know which pins on the computer are being monitored.

edit:
just re-read your post... only one wire coming off the relay into the computer?

[hng]

Would this relay work?

relay

[BobA]

It will work for the voltage and probably is fast enough if 15 ms is within the timming of the stepper relay.  Since I have no idea about the makeup of the stepper relay signal I am guessing.   There are two wires to the RS232 port.  The data pin and probably a ground connected to the NC or NO contacts on the relay.    Sorry I cannot help more but I am just trying to assist by best guess not with any knowledge of the actual wallbox signal as I have never worked on one and am going by the written description.

Edit:  I just thought that the relay chosen should fit in the enclosure that the commercial unit uses.  So if your relay is bigger then the box that they use it is probably too big.  Some relays are much smaller and faster.  They are called reed relays and are used alot on circuit boards.  Just an idea that came to me when i was thinking about the relay you chose which might be too big and massive. Thus a bit slow.  You do not need a 10 amp current capacity.  Only milliamps.

[hng]

cool... I think the relay I linked was about the size of an automotive relay. I was just doing a quick search, and I did see the reed relays. I'll definitely look into them.

[Barry Barcrest]

if you fedding this into the com port you could code a small visual basic program to monitor the port.

Here is the pinout for the com port.

http://www.aggsoft.com/rs232-pinout-cable/pinout-and-signal.htm

You will see there are TX and RX pins

[Carlito]

I'm not quite sure about this (again I'm no serial port expert) but do we really need a relay involved here?
Instead of using the 25VAC pin could we not use the signal pin and monitor that.
In essence is it not already doing the job of the relay?  I can double check the voltage coming out of the signal pin but I believe it is only 5V.
Again, forgive me if this is totally inaccurate.

Carlito

[BobA]

I thought that the 24vac was the only voltage involved.  No signaling line.   Just power on and off.  But since I am only going from what I have seen in this thread I could be off base completely.  When you are measuring the voltage are you using acv or dcv and if it is a pulsed ac do you can you  know that a pulsed AC can show up as a much lower voltage because youare only summing the RMS value withing the limits of your meter.

[Carlito]

Hmm, after double checking the manual I can't seem to find anywhere that says how much is coming off of the signal post.  Guess I made it up And as you said, it's hard to actually check it.
But yes, there are three posts in all.  Signal, 25VAC and GND.
From the manual it states:

The Wall-)-Matic operates at 25 volts AC, 60 cycles.  Power is supplied by the Power Supply Unit (which I have built)  Two of the three wires of the interconnecting cable carry power to the lights and motor.  The other wire and one of the power circuit wires comprise a selection circuit to provide remote control of the operation of the selection system in the phonograph.

So what I get from that is that the signal post will effectively act as a relay and send short spurts of 'pulses' which we should be able to read from a serial port somehow.
But then again, maybe I'm reading that totally wrong.

[Ken Layton]

Those pulses on the signal line have voltage on them! This is not simply a relay closing. The signal line sends pulses with an ac voltage on it.

As originally designed, the wallbox sent a 'signal' to the "stepper" unit inside the jukebox. These pulses were amplified by tubes (usually a 12AX7 and a 2050 tube)then went to a group of stepping relays which translated these pulses to the jukeboxes selection system.

[BigBird0000]

Has anyone solved the wallbox to PC (serial or usb)?
If so, are you willing to share your knowledge?

TNX

[BigBird0000]

For Anyone That Is Interested

(for Seeburg 3W1 - others will vary)

This operat1on is dependent on the number of pulses and the intervals of time between them.

Two series of pulses are required -- a first series for the selection of a selector coil circuit and a second series for selection of a group solenoid.

The number of pulses in each series is determined by which Wall-0-Matic selection
switches are pressed. There will be from 2 to 21 in the first series and from
1 to 5 in the second series.

The rate of the pulses and the time interval between them is determined by the design of the Wall-0-Matic and the motor speed. This interval between individual pulses in both series is approximately 1/25 second and an interval of approximately 1/5 second occurs between the last pulse of the first series and the first pulse of the second series.

The motor is designed to operate the Wall-0-Matic through a complete cycle in a
little more than 2 seconds. If the motor is slow, the current impulses to the step relay (in the Selection Receiver) will be slow and cause erratic operation of the step switch assembly. The motor can best be checked for speed by allowing it to operate steadily and counting the turns per minute of the contact arm. Normal speed is 24 revolutions per minute. Acceptable speed limits are 21 to 26 rpm. If the motor is slow, check for binding or excessive friction. If the motor runs slow when there are no hinds, it will have to be replaced.