Anyway...

Although Im still waiting for the new LL Pro Lens set to come in, and I havent finalized the design for p-brain version 2 (you can read all about p-brain V1 development here: http://www.diyaudio.com/forums/showthread....&threadid=62055 ), I thought I'd start my PLOG anyway.

My current test bed projector has:

- 15" Benq 567
- 250 watt HQI Bulb
- ICECap Ballast
- LL Standard Lens Set
- LL UV Protection film
- IKEA napkin ring reflector
- P-Brain Version 1 DIY Projector controller

Here's the plan...

To build a new HDTV projector utilizing a 17" LCD, the new LL Pro Lens set, and the 400 watt LL lamp kit.

I already have the lamp kit.

What I need 1st are suggestions/comments about the following...

1) Which LCD should I use? Ive been eyeing the Westinghouse 17W7 for its contrast ratio and response time. I want a PJ that I can watch movies on, and play Video Games. (If I can ever make up my mind on whether to buy the new XBox, or the soon to be released Playstation)

2) What other features to incorporate into the P-Brain V2? So far, in version 1 I have:

- Lamp Power control
- Fan power control
- Fan fault detection
- Projector Indicator control
- Audible warning beeper control
- No motion detected timeout after 3 hours shutdown
- Timeout after 6 hours if power button not pressed shutdown
- Leave fans on for 3 minutes after bulb extinguished

V2 has all V1 features plus:

- IR Remote control (Turn the PJ on off, or reset timeouts using an IR remote)
- Bulb life counter (how long has your bulb been lit? How long did that last bulb last?)
- Serial PC interface (control/configure your PJ from your PC)
- Fan speed control
- Temperature sensitivity (Lower fan speed unless the PJ becomes too hot)
- Projector boot counter (how many times has the projector been booted?)

* A couple of people have mentioned that they would like to see electronic keystone correction, however because of the fact that folks build their projectors differently, this would be difficult... very difficult to do in a generic fashion. Some people do straight through PJs, some do folded, some fold once, some fold multiple times. Trying to incorporate a generic Keystone correction mechanism in an environment like this, could happen but it would be very difficult to get to work properly in all cases.

So...

My intent is to design and build a projector based on Lumenlab components using Lumenlab subscriber's input as to how it should function.

HELP!

Ambitious project... I'll be interested to see how you tackle it.

Obviously keystoning requires a good bit of custom mechanical design... but would you consider integrating remote focus control? It'd just be a two-way control over a motor.

I know most of your p-brain's capabilities are diagnostic -- I'll be wracking my brain to think up some other possible functions.

Any kind of mechanical movement would be difficult to do because of the fact that there are many ways that people accomplish the task of video projection. Sure there are many who follow an exact specified mechanical plan, but there are all kinds of DIY projectors out there. The focussing mechanism on my projector is definitely mechanically different from most others. So if I designed an automated focussing mechanism for my PJ it probably would not work on the next PJ I built unless I built it exactly the same way. I mean... could you use a mechanical/motorized focussing or keystone correction mechanism that works on a 15" straight through projector on an 8" LCD projector with a folded design? Maybe... but... something would have to give.

Sounds great!
I was planning on having ir controlled focus and tilt control in my Ver2!!
I have an oopic-r sitting in my garage doing nothing,so I thought I could put it to some use!!
I look foreward to your build,it sounds like it will be very interesting.
Cheers P
( BTW: Xbox all the way,you cant beat xbox live!)

Nice Plog, you forgot 1 thing a luxmeter

DIY Luxmeter

Oh sure... if you are going to build a custom focussing/keystone mechanism for your projector design then go for it. Just keep in mind that it probably wont transfer very easily to your next design.

IMO keystone correction could be done better without the electronics. Just build a Knob into the projector that connects mechanically to the field fresnel and use it to tilt the fresnel one way or the other. To add motors to it would be cool but only if those motors knew how to adjust keystone without human intervention based on projector tilt. If you manually have to adjust keystone what different does it make if you have to turn a mechanical knob, or push a motor control button?

What Im trying to do is to build a generic control that works for multiple projectors (I plan to have at least 3 projectors so I dont want to have to reinvent the wheel for each one). The controller should implement a basic set of standard functions that all projectors should have.

The way I see it... The true trick in getting everything right with this is to:

1) Enlist the assistance of the DIY projector community.

- P-Brain V1 was deisgned in part by me... and in part by the DIY PJ community.


2) Actually put the thing into a projector and live with it for a while.

- How well do certain features fit my lifestyle? Dont know till I use it..

Looks good, although I would go with thermal shut off for the fans, 3 minutes after shut down is not long enough unless you are using turbo fans from an air boat! Mine takes at least 30 minutes to cool down properly after bulb shut off. In pj2 I have an attic fan control and it takes 15 minutes to cool before it shuts off the fan. I also like mechanical keystoning with gravity, and if its a big angle you can tilt the screen to match the angle of the PJ. I agree with Pun15her, Xbox all the way!

All the times will be configurable...



Actually there is kindof a built in luxmeter in the current version, but its being used to detect light coming directly from the bulb and the controller either sees or doesnt see light... it doesnt measure the light incrementally. If there was a real luxmeter in there... where should the detector be positioned?

Good point, i guess the sensor would be located near the triplet but should not interfere with the projection so i dont know if it would be possible. Such a luxmeter would be great for tweaking adjusting your PJ.

One feature that I think would be neat is something that can interface to the LCD itself to replace the buttons for contrast/brightness, menu, etc.

Basically, since you're gonna have an IR remote anyhow, you just need to have a system that will map buttons on that remote to switches on the control panel. Then your p-brain can have inputs that it switches closed when the corresponding buttons are pressed on the remote. The end user would have to take cut the wires from the button panel and connect them to the appropriate p-brain inputs.

Is that making any sense?

Also, is an RF remote a possibility? Since so many people are trying to get the PJ's above/behind the seating area, IR might be an even bigger pain in the butt than it is with a regular TV.


Hope this helps,

Yeah it would be hard to position it so that it was getting a good measurement but wasnt in the light path.



Yeah it would be cool to add control for the LCD... In my current version I just control the LCDs Power via a solid state relay. I see there being two different approaches to this: 1) use relay closures to replace the buttons, or 2) Mimic the electrical signals coming from the LCD keypad and send them directly to the LCDs controller board. It would probably be easier to do this using relay closures because that way the controller would just need to know how many buttons the LCD had then map an IR pulse stream to a button.

Actually you can do this without an entire "Projector Control System". Take a look at this:

http://www.rentron.com/remote_control/IR-D15A.htm

This chip is a dedicated IR Decoder that comes preprogrammed with several manufacturers IR remote control codes. All you need to do is add a power supply, IR detector, and your relays, then wire the relays up to your LCDs keypad... and voila! Heck... you could even use it to control your lamp/fan power/etc from an IR remote, with a little extra circuitry. Only problem is it only does Sony codes, so its possible that it could conflict with other equipment you might have in the room. To get an even better solution, the IR detection mechanism would need to incorporate a "Learning" capability so that you could use any remote, and any buttons on that remote for control.

As for the RF vs IR, from my experience IR detectors are pretty good at picking up IR pulses even if you arent pointing the remote directly at the detector as long as the remote and the detector are in the same room, and the batteries in your IR remote arent low...

I was thinking of exactly the approach you describe in #1. Although I was thinking that transistors would serve just fine as switches - no need for relays, I'd think.

I know that this can be done without a complex PJ controller - but you asked for features to be incorporated into the controller, and this one seems like an obvious one to me.



Wow - your experiences with RF are the exact opposite of mine! If one of my cats is between my IR remote and the detector on my TV or DVD player, then it's useless, regardless of the battery strength.

Personally, I'm officially boycotting any IR remotes from now on whenever possible, which is why I'll be driving everything from my HTPC with RF remote.

Of course, if you built it such that the IR detector is beside the projection screen and ran the signal wires back to the PJ controller, then using the IR remote it would be nice and intuitive.


Hope this helps,

Yep transistors should work. What I was thinking was that using relays might be the easiest way to mimic a button press, without having to know anything about the electrical signal that pressing the button generates to the LCD controller board, and It would also keep the controller electronically isolated from the LCD.

Dont get me wrong... the more I thought about your suggestions, the more I liked them.

I only mentioned using the other method (stand alone IR Decoder and relays) as a possibility for someone who might be listening in and just wanted that specific funtionality in their projector without embedding an entire control system.

That same website I mentioned in the previous post has quite a few RF remote control projects as well... It might actually even be easier to implement than IR since there are no funky IR codes to worry about, I could just transmit commands from the remote to the controller as a serial data stream over RF. There wouldn't even be a need for implementing "Learning capability" as would be required with IR because I could just build my own RF remote and design a proprietary serial communications protocol to communicate with the controller.

Hmmmmmmmmm...I like this...(rubbing beard) now youve got me thinking.

As I understand it, you'd need a transistor to drive the relay anyhow, so rather than using the transistors to drive the relays, just use them to close the circuits in place of the panel switches.


Uh oh!

Good luck, and keep us posted,

Actually Im considering doing a little side project based on what we've been talking about...

The way I see it... people always like to have a choice...

Small,Medium,Large,X-Large.

I think that projector control systems can be designed to subscribe to that paradigm.

In otherwords... instead of building a solution where everyone had to have an "Intelligent Projector Control System" to control their projector... there may be some mid points where they could get a certain amount of control without a complete, all encompassing "Brain" being embedded.

For example:

Currently I have P-Brain Version 1 embedded in my projector. It controls basic functionality (Lamp/Fans/LCD Power/Auto shutdown/etc)

Now... from here I can go in many different directions...

I could build P-Brain Version 2 which has all the intelligence of V1 plus a bunch of other features...

OR

I could build an add on to P-Brain 1 that adds more features but doesnt require dumping P-Brain 1.

What am I talking about?

Ok... lets forget about the P-Brain controller for a minute.

Lets say that I could build an embeddable system that didnt have ANY "Intelligence" but could be controlled via RF remote. So this way you would have an RF remote in your hand... you would push one button to turn on the lamp, one button to turn on the fan(s), one button to power the LCD. Of course the Lamp On button would also have to send the fan on command so that you dont turn on the lamp without the fans being on. So basically via the RF remote you could turn the fans on without the lamp, but you could NOT turn the lamp on without the fans.

NOW...

Lets say that on that same remote, the LCD control buttons/functionality was already there, but wasnt usable till you embedded the LCD controller board. Once you embedded that... from the same remote you could now control your LCD functions as well as your lamp/fans etc.

I LIKE IT!!!!

Then.... If you were REALLY hardcore, and wanted the FULL BLOWN projector control system, you would embed the Brain board, which would add intelligence to the whole system.

Im really digging this... but... it would be pretty hard to do (this is the ultimate system) because I would have to design a control system that would work now, and when the other pieces were plugged in... Its almost like trying to design a PC where you design the backplane/motherboard, then the Video Card/Network Card/etc.

AND!

It would have to be designed so that the "Motherboard/Brain" need not be installed to get the basic functionality of controlling the lamp/fans/lcd power via the remote.

I think the best way to approach this goal is to build each system independently... then figure out how to integrate them later.

This being said...


Since I already have P-Brain V1 in my projector, Im thinking of doing a side project to build an LCD controller that is NOT integrated with the P-Brain but provides control over my LCD. This would be a separate circuitcard/system. It would be something that could be installed into a projector, and would just provide LCD control functionality, and would NOT need a brain to do so... just the remote. When I embed it into my testbed I would have 2 Independently functioning systems that are not integrated. 1) P-Brain and 2) LCD-Controller.

What the End Game is... is to have

Small: Control Lamp/Fans/LCD Power via remote

Medium: Control Lamp/Fans/LCD Power/LCD Functions via Remote

Large: Intelligent Control over the entire projector with Remote control functions

Sound design. Good plan. Fun project.