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DynamoBen
08-01-2007, 12:07 AM
The subject of this thread is a little deceiving but let me explain. I just finished watching a presentation at OSCON about open source hardware, present and future. I found it very interesting and exciting, but it got me thinking about DIY Christmas hardware.

I like most on this forum I am an electronics hobbyist and am interesting in building my own dimmers. While I understand electronics, and could design my own dimmers doing so takes up both time and money; both of which are always in short supply. ;)

Between this forum and Computer Christmas there are literally dozens of different hardware designs and methods for controlling lights. While all a great they all have their advantages and disadvantages. For me I really wanted my dimmers to have local SCRs and receive both DMX and RDM, nothing like that really exists.

How cool would it be to have DIY dimmer “building blocks?” Most folks here are familiar with Sean’s SCR blocks, what if you could buy several SCR blocks and either solder on a connector for remote use or solder on a header for local use. Then you could purchase or build a “motherboard” that you could plug/cable your SCRs too. For this example lets say that the motherboard is Pic microcontroller based, so you buy a microcontroller for it. Lets say the microcontroller and motherboard allowed you to load whatever “flavor” of dimmer code you wanted via a serial port; it could be anything from lynx, to renard, or whatever else it out at the time. Finally you add the interface from the dimmer to the PC, for this example you add the RS485 interface. You’re done…you have a fully functioning dimmer.

The advantage with this method is down the road you could change the dimmer as you see fit or as something better comes along. In addition the smart folks on the forum can focus on firmware updates and additional “building blocks” to extend the dimmers capacity instead of being spread out over multiple projects. And going into the future these building blocks could be used to do automation, video, you name it. Now I’m not saying get rid of all the individual development, I’m saying focus efforts toward interchangeability and creativity.

What I have in my head that might be similar is products like Arduino, the Basic Stamp and EFX-Tek Prop controller. The hardware is partially complete, you can buy addition interfaces, you set it up the way you want; you can use existing code or create your own…and away you go.

Maybe I’m missing the mark here but I thought this might spark some good discussion.

So what do you think?

If you are interested watching the video from OSCON about Open Source Hardware this is the link:
http://www.makezine.com/blog/archive/2007/07/phillip_torrone_and_limor.html

stempile
08-01-2007, 12:31 AM
Sometimes people are selling there finished DIY projects on this forum. But for me its all about building it from scratch from plans and co-op PCB or homemade PCB.

There are commercial kits to build SSRs, and computer controlled ports already out there already. They are copyrighted and tested by professionals that have insurance. I wouldn't sell anything I made because I don't want the liability when the end user hooks it up wrong and damages something...

Taking a plan from this site or other DIY site and making it "available in a package" is difficult due to possible license and legal issues.

ms

DynamoBen
08-01-2007, 12:57 AM
Sometimes people are selling there finished DIY projects on this forum. But for me its all about building it from scratch from plans and co-op PCB or homemade PCB.

Please don't misunderstand I like the co-op and homemade methods, that would be what makes this all work. None of this would be for capitol gain.

The goal would be to get folks working together on toward a common goal with an emphasis on expandability and flexibility. For me coming up with design ideas and writing firmware is cool but I'm not that great at laying out circuit boards or specifying parts. But I know there are other that really enjoy and excel in these areas...I want to link up with them. For me I would much rather take an existing hardware platform and use it as a building block. Kind of like Vixen, its the main platform but the plugins add features and functionality.

P. Short
08-01-2007, 01:12 AM
I'm not sure that I understand where you are trying to go. Is modularity what you are looking for - a Lego-like building block approach?

--

Phil

ErnieHorning
08-01-2007, 08:05 AM
I’m not sure what’s being asked either.

“Open source hardware” as defined in thousands of places on the internet means that every file needed to understand and rebuild a project is open and readable by either open source programs or at least by freely available commercial tools.

Just like open source software though, you still have to do the final assembly.

pete
08-01-2007, 08:25 AM
In most case we do have just what ben is looking for just a little backwards. our base for most of the different types of controller is Sean's SSR boards. If I've read right most of the available control boards that don't have there own SSRs on board will work with Sean's SSR boards.

DynamoBen
08-01-2007, 10:42 AM
I'm not sure that I understand where you are trying to go. Is modularity what you are looking for - a Lego-like building block approach?


Kind of like that, keep in mind I'm just thinking out loud. The idea would be share common pinouts and designs. For example I could build a pic based dimmer that uses Sean's SCRs, mount them directly to the board, drop a pic on it, and then load my own firmware. The pic based "motherboard" would be a building block; Sean's SCR would be another building block. This eliminates the need for me to design something from scratch and opens things up for future development and enhancement.

I guess the ultimate goal is to take the best parts of the like designs and make one common platform design. So the board would have a pic, hearder locations for serial, usb, DMX, and possibly Ethernet. It would use a "standard" socket size, lets say 28 pin dip. You would have the option of populating the board base don your needs and loading the firmware that fits those needs. That has kind of happened with the parallel stuff, but hasn't yet happened with the microcontroller stuff.

ErnieHorning
08-01-2007, 02:24 PM
Really what you’re asking for is a development board. A main board that functions as a backplane and several headers (or slots) that allows you to pug in various inputs and outputs. Why not also allow the processor to be changed as additional I/O or processing power is required. The down side of a system like this is that you’re still guessing what your future expansion needs will be.

I created a system like this at work that emulated 37 different thermostat models. Everything was configurable (keyboard, display, power supply, outputs, A/D, memory, the processor was an emulator so it was externally configurable). This was quite a task since the micro’s pin assignments were different depending on the model. In the end though, I believe there was only a couple of flying jumpers between modules.

DynamoBen
08-01-2007, 03:31 PM
Exactly. Ardiuno has things called "shields" they all share a common pinout but each has a unique set of functions. You can purchase any shield and it can dock on the microprocessor board, just update your firmware and you are going.

Normally I develop with PicBasic and they programmer via ICSP. The trouble is PicBasic is fairly expensive and you have to purchase a programmer. Its a bit beyond the casual hobbyist. Because of this I've been doing some research on alternatives like PicAxe.

What’s nice about the PicAxe is it comes with a boot loader and a free IDE for programming (like a Basic Stamp). But because its a standard Microchip Pic the pinout follows Microchips standard, which is fairly consistent from pic to pic in the same series. Designing around the PicAxe would allow folks who are interested in developing or customizing an inexpensive and simple way of doing so. For folks like myself I can still program the conventional way using a pin compatable Microchip Pic.