Ability to drive multiple IR transmitters independantly from PC

The RS232 serial commands are listed in the user manual. I would forget about IR.

You can get single port USB-serial adapters for $10 each. Run 4-wire modular cable from the RS232 end of each adapter to each projector. Cost: $10 + cable + connectors per projector. The only problem is getting 20 USB ports to plug the adapters into. I have 4-port USB expanders on a couple of machines but I haven't seen a 10-port or 20-port version.

Hi Alexis

I think (IMHO) the cheapest way forward would be to purchase a USBUIRT

Then make your own Homebrew Transmitter Zone Selector using say a pic micro.. Or connect the USBUIRT output to something like this...

Also with my FirM Kit if using only the Transmitter function no FirM Receivers required.......but as i mentione a serial interface would be required....

HTH Frank

Alexis, global commands should not be a problem if you incorporate them in the VB program running on the PC (Channel1, Channel2, ....All Channels, something like the All Lights ON in X10), and program the PIC to respond to that, besides the individual pin control.

Yes; you would only be restricted by the number of I/O pins available on the PIC. For a standard 40 pin that would be about 33 channels! And of course you could use even more PICs, if required, each having its own address.

Do you happen to know if

Are you referring to the hardware (PIC, Relay, USBIR hack) or the (Serial port, PIC)?

You'll find a lot of answers on the URL I gave above.

This is getting interesting. I'd love to help you all I can, so feel free to ask for more details. I'm travelling over the week-end, though, so I can only repond on Monda/Tuesday.

Regards,

Anand

An more costly alternative, if the PC has enough ISA or PCI slots available, is to do it with true RS232 ports using Byterunner 8-port serial cards.

If you're going with serial get some EdgePort multiport adapters. I've used their 4 and 8 port adapters and they're GREAT. It's MUCH better than using multiple single USB-serial adapters, if only because of avoiding the software driver NIGHTMARES. Get two 8 port and one 4 port adapter and only have to use ONE software driver and three USB ports, most likely just chained to a single hub.

Agree on all counts. The Edgeport made my life a lot simpler.

I got my 8 port very cheap on ebay.

In article , snipped-for-privacy@whocares.com (Dave Houston) writes: | Alexis wrote: | | >Dave Houston wrote: | | >> What are the details on the codes you need to send? Carrier frequency, code? | >> It may be possible to design something quite cheap to accomplish this. Can | >> you program in Basic? | >

| >I have to admit to my ignorance on this unfortunately. The projectors | >are NEC VT650 models, but unfortunately I'm unable to find any details | >of the IR specifications on the 'net. Is there anything you can suggest | >without knowing this information? | | The RS232 serial commands are listed in the user manual. I would forget | about IR. | | You can get single port USB-serial adapters for $10 each. Run 4-wire modular | cable from the RS232 end of each adapter to each projector. Cost: $10 + | cable + connectors per projector. The only problem is getting 20 USB ports | to plug the adapters into. I have 4-port USB expanders on a couple of | machines but I haven't seen a 10-port or 20-port version.

Another possibility would be to use one or more Ethernet terminal servers. IOLAN 16-port units can often be had cheaply on eBay. They can be configured to provide a transparent tcp/ip connection to each RS232 port. The application on the PC would open one socket for each projector connection. An advantage is that all you need on the PC is a standard Ethernet port.

Dan Lanciani ddl@danlan.*com

Bill, you sure have a lot of nightmares where others just have have sweet dreams - perhaps you should lay off the late night stacks. The single port adapters will use ONE DRIVER and cost less than the multi-port units. (At least, they cost much less, about 1/2 as much per port, than the multi-port units offered by Byterunner.)

In any event, Dan Lanciani's ethernet-serial suggestion, since it only needs one ethernet port, is probably the easiest way to go if you can find a cheap used unit. I don't usually recommend eBay because I prefer to look my fence in the eye when he tells me, "It fell off a truck". ;)

Assuming you make use of single port devices all from the same vendor and the then the same model/production run. While a number of them do base themselves on the same chipsets not all make use of the same driver software, and some are worse than others. Then there's the USB bandwidth and power issues. There you're running up against how well (or poorly) the hardware and drivers for the USB ports are set up.

I'll trade time wasted wrestling with bad drivers for a few extra bucks on a multi-port instead.

BULL!

Under Windows...

ALL FTDI chipsets work with the same drivers. (They offer both VCP and a direct interface with an API - the device developer chooses which.) ALL SiliconLabs chips work with the same driver. I haven't tried anything with the Prolific chipset but the fact they offer only one driver speaks to the fact that they must all work with that one driver.

I have used multi-port hubs. If you search, you will find I was the first to post about them here several years ago. The Entrega (later Xircom, later Intel) 4U2S1P hub was one of the earliest. There's absolutely no difference in operation between the serial ports on such hubs and multiple single port adapters from the same manufacturer which is exactly what I recommended, even giving a URL to the specific adapter.

I have an adapter made by FTDI using their very first chipset. (I think I was the first to post here about them.) It works with the same driver as any using their latest chips as well as any in between. I have 3 different SiliconLabs chips (CP2101, CP2102, CP2103). All use the same driver.

I have had an FTDI based adapter, 2 SiliconLabs based adapters, the Entrega hub with two USB-serial ports, a USB-UIRT (uses a later FTDI chipset) and a Byterunner 8-port PCI card on the same PC along with two motherboard serial ports with absolutely none of the fictional driver "nightmares" you predict. Windows finds the new hardware, asks for a disk if it doesn't already have a driver, installs the driver once (if needed) and operation is transparent and uneventful thereafter.

I have reassigned port names to test that my software can enumerate and connect to COM1-COM99.

I believe the FTDI and SiliconLabs drivers have been added to the Linux kernel. The FTDI drivers are included in XP.

Macs never had true serial ports and some of the USB-serial adapters originally designed for that market are the ones most often complained about by folks who try using them with PCs and applications that need all of the handshaking lines.

You've named at least three chipsets, I'm sure there are more. I've worked with quite a few of these adapters over the years (from at least a dozen different vendors) and have had very little success with getting most software working with them on a consistent basis. There's plenty of points of blame possible, from the software itself doing a bad job of just using serial ports, hardware conflicts (irqs, etc) and that's all before getting to the USB driver's layer. So in the real world there's lots of room for problems. Thus having found success using multiport adapters I'm given to encouraging others to trying it.

I'm not talking about hubs. I'm sure you're delighted with your vast array of knowledge, thanks for sharing.

Well, here you're plainly wrong. Granted, they weren't PC comm ports in the traditional sense but all (nearly?) pre-USB macintoshes came with two serial ports. 422 capable as well.

And I've never experienced any such difficulties. Go figure.

They had RS422 ports which use balanced signals. That's closer to RS485 than to RS232 which uses unbalanced signals. Most people would regard RS232 as "serial".

The ports would do RS232 just fine, this in addition to being able to do their Localtalk/Appletalk scheme based. What this has to do with USB-serial adapters is anyone's guess...