need Multiple USB Display project help

Kristof1965

New member
Here's my original project idea:

Multiple (8-10) LCDs connected to a controller hub that is connected to a PC. From the PC I will be able to send messages to each of the individual displays, or all of the displays together, or just a select few. I can either type From the PC I will be able to send messages to each of the individual displays, or all of the displays together, or select a group of two or more. I can either type (or cut/paste) a message into a displays "window" and send it, or I can select from a drop down list of messages and send one of those.

I originally planned to do this with the same 20x4 AZ Displays my company uses and pay one of the electronic engineers at our sister company to design the parallel interface and program for me, probably using an AVR Microcontroller.

But then during the search for parts and pieces I found CrystalFontz, and I realized that the 632 and/or 631 would probably meet my needs, cost the same or less, possibly have more features (if I use the 631), be quicker to get up and running and maybe, just maybe I could handle most of the programming myself. I'm thinking from all the info I've browsed through here that it shouldn't be too difficult, the hard part is actually selecting what I need to purchase and at what points I'm going to need help.

So here's my re-imagined project, and then some questions:

8-10 631 (or 632) displays, all connected to a USB hub, which is connected to my PC. Again, from the PC I will be able to send messages to each of the individual displays, or all of the displays together, or just a select few. I can either type (or cut/paste) a message into a displays "window" and send it, or I can select from a drop down list of messages and send one of those. It's very important that I will be able to access all of the displays from the same screen and send to multiple displays at once. In addition, if I go with the 631, I would like each of the buttons on the 631 to trigger some sort of alert message/event (haven't decided exactly what, yet) on the PC AND tell me which display it came from.

1. Are there any known issues with running multiple USB 631/632 displays off of a hub?

2. Are there drivers available for running the multiple displays and addressing each of them individually? Or would the standard drivers handle that?

3. My programming experience is limited to about 15 years of basic (pre visual basic days), Excel spreadsheets/macros and my companies proprietary E-Code (which is like a menu driven basic for I/O control). Given that back ground, any advice on what parts to farm out to a professional and what I can do myself?

4. How difficult will the button programming be from a driver stand point?

5. What programming resources would you point me to from drivers/tutorials/etc? I will probably be programming in VB if I do it myself.

The part that scares me about tackling this whole thing myself is the required drivers. I know enough about what I need from the my user interface to know I can handle that part, and as long as I have an straightforward method of sending to/receiving from the dispay within VB, I'm pretty confident I can stumble through that portion as well. After all, I'm not gathering data from WinAmp or my system properties information to send and constantly update - I'm just sending text and possibly recieving button presses.

Thanks in advance,
Chris
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CF Tech

Administrator
You should not need any special drivers. Each display will typically assign itself to a new COM port.

So your program only need to find out what COM ports are available on the system (an example is in 633_WinTest) and open all the COM ports that have "CFA-635" in their identifier.
 

Igor

New member
Hi Kristof.

Did you get any final answers?

My projest is similar to your, i even require up to 30 displays. My question is about possibility to connect all these devices to one pc. Will there be possibility to create 30 com ports? Is there a chance to work stable? What about power? So much displays - will there be no lack of power from usb hubs?

I found usb hubs for max 7 devices (d-link) - have you found one
with larger amount of slots?
 

Kristof1965

New member
No final answers. I ran into two problems, so I can't realy proceed anyway - a financial crunch combined withthe demise of my laptop.

Until I get those resolved, I'm dead in the water anyway.

Even though I've seen a hub max size of 7 as well, I've daisy chained two 4 port hubs before, and, as I understand, theoretically, you can daisy chain as many hubs as you need. How the system will handle the Com ports is a question I can't answer, though.
 
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