que line waiting time display

[gadget-evilusions]

I am starting a new project.

I want to build a system that will use an rfid tag and reader, probably a prop-2, and a display to simulate something I saw at Florida Disney this past October. Every so often the staff would hand a person getting in line a special lanyard (I think with a rfid tag in it). When they got to the front of the line it would update a display with the current average waiting time for that attraction. At least that's how I think thee did it.

The one part I can't find is a large enough display that can be feed info from the prop-2. I have used parallax LCD displays, but they are obviously too small for a public display of information application. Does anyone know of a display that would work?

[Jeff Haas]

There are big displays available from a company named BetaBrite (http://www.betabrite.com/). There's open source code, designed to be run from computers, available.  Here's a website with info:

http://dens-site.net/betabrite/betabrite.htm

I originally looked into these so we could have a wall display at work that would update with data from a server.  There's also info in this PDF that mentions hooking it up to a microcontroller:

http://www.industrologic.com/betabrite.pdf

There's more if you Google "betabrite microcontroller".

[bsnut]

Brain,

I  found this on the web and may want to take a look at as well http://www.kronosrobotics.com/Projects/Alpha1.pdf about using an Betabrite sign with an microcontroller.  From what I see it will work with a PIC microcontroller with no problems form looking at the code.

I also looked at, the first site that Jeff Haas posted, which I like the best and think it may work with the Prop-2 or the Prop-SX. But, you my want to do some expermitents with the Prop-2 or the Prop-SX to see if wll work with these controllers. This site also shows you how to do make up the cable as well. 

If you can wait the HC-8 maybe able to handle your task without any problems. Why I say this, is because the Propeller chip can be programmed in "C". But, I would ask Jon first. Since the birth of HC-8 hasn't happen ;D.

The other cool thing, is these signs can work what RS-485

[JonnyMac]

If you can find one of those signs that work with RS-485 then the HC-8+ is the ticket.  Why?  Eight cogs (processors), baby.  You could use one for your main program, one to listen to the RFID port, one to run a precision timer, one to talk to display -- and you still have four processors left!

Since the birth of HC-8 hasn't happen

Good things come to those that wait....

[gadget-evilusions]

So, I found a couple options that are a little lower tech. I never thought to google giant 7 segment display.

This one looks pretty cool.  http://www.sparkfun.com/products/8530

Although it will take a little programming time for me, and probably the last of my dc-16's to be able to hook up 3 or 4 of them.

This one is cool too, just way too big, and not 12v.

http://evilmadscience.com/productsmenu/partsmenu/107-sevensegment

[JonnyMac]

Mind you with those big 7-segment displays you'll have to create a multiplexer/driver circuit.

[gadget-evilusions]

Is a multiplexer/driver circuit like that commercially available? I don't have the skills to make one myself.

[JonnyMac]

No, they're not, but we can help.  If you use an HC-8+ as the master controller then you could use three of the 5v outputs to drive an SPI chain of TPIC6A595 chips (one per digit).  These chips act like shift registers with very high current outputs (350mA per channel with all on).  The are also active low (like the ULN chips) which would work with the SparkFun digits.  I could write you a custom app for the HC-8+ hardware that would drive the digits.  It could even go back and forth between the wait time and the actual time (I'm working on an RTC add-on module for the HC-8+/FC-4+/RC-4+). 

If you want to go that route I'll draw a circuit for you that will be simple to make.

[gadget-evilusions]

That sounds awesome Jon. I would appreciate it very much. Then i can build it right after Hauntcon

[JonnyMac]

Let's talk about it while we're at HauntCon.

[gadget-evilusions]

Will do. Thanks.

[gadget-evilusions]

Jon,

I hate to bring up a really old topic, but are you still willing to draw up the circuit for driving these large sparkfun 7 segment displays? I have a project right now that I would love to use 4 of them for, and an HC-8, to be a count down clock. 60 minutes to zero.

[JonnyMac]

Why did I not post that before -- let me check to see if I have that drawing.

Questions:
-- You're still going to use an HC-8+?
-- You want to control four digits?

I've used the TPIC6A595 with the Propeller so I already have code for it. I also have a new timer object that I've been using a lot that simplifies delta timing.

[gadget-evilusions]

Yes, I want to use the HC-8+

Yes, I want to control 4 digits with this current project.

Please tell me if this is possible:

At power up of controller, digits display 60 00
Button 1 starts countdown backwards to 00 00 in real time
Button 2 pauses countdown and unpauses countdown
When countdown reaches 00 00 digits flash 00 00 with a frequency of off for 1/2 second and on 1/2 second until button 3 pressed
Button 3 resets display back to 60 00 until button 1 is pressed to begin countdown again

[JonnyMac]

I think I can do that. I will have to test using serial output to a terminal since I don't have the displays -- I'll leave that in so you can experiment without having the displays.

By the way, that is 60 minutes, right?