Originally Posted by Darkknight512;12476065
Hey everything looks great, I'm in a high school shop class and I could learn a thing or two from you.
So about your fan controller idea, I don't know if you know much about computer programming and electronics but it's quite easy to build your own programmable fan controller.
An Arduino Mega is about 50 bucks, you can hook in 1 or more, 20x4 character LCD's ($20 bucks a peice) with your choice of backlight. Then you have pins for plenty of buttons ($1 for all), up to 15 knobs/temperature sensors ($1 for each temp sensor, $1 for a bunch). Then your have 12 PWM pins for fan control which you hook up to the red wire (through a power transistor), after that you just hook up all the black wires to a 12 volt source. The Arduino itself can take 12 volt as well. You should even be able to program in a shutdown sequence, have some way of detecting the power to the computers, whenever the power to the motherboard turns off then the fan array will turn off after (time delayed), or you can have fan off be manually controlled (possible with time delay as well) if your paranoid. The other problem is, the only way I know how to read the RPM is to use an interrupt on the controller, however I don't know how much CPU time that takes up, and the board only has 6... however you could still show the fan speed % on the screen because the controller knows that.
With enough power you should be able to drive as many fans as you want, even up to a ridiculous amount of power. If you want more fans, just get some multiplexers for the PWM (much more complex). Easier is to use the built in serial lines to daisy chain more micro controllers.
You could if you want have the micro controller control anything else (custom desk/case LED lighting?), laser trip wires, infrared blaster (maybe just power/channel/volume for a TV from your desk, no more remote!), make an alarm clock, motors, or anything else you could think of.
This should all be doable with about 500-1000 lines of code, if you know what your doing it should be done in about 2-3 days.
I would love to help if you need, I'm currently in the process of designing an automated watering system. I'm in Toronto if you want me to help with the programming and electronics.
Oh my. You're giving me some pretty fantastic ideas. I took logic circuit programming, as well as a bit of Java, C++, and other bits of software programming, so I realize what is possible, but I've never dabbled in the boards available for enthusiasts before... I will have to keep that in mind when it comes time to control the fans, etc.. Thanks!
Originally Posted by jpz;12476460
An Arduino Mega is way overkill for a fan controller. It's also a huge waste to use a development board in a finished product. If you don't already have a hardware programmer or development board and some experience you might as well just buy a fan controller. It'll cost about the same, you'll save yourself a lot of trouble, and likely end up with a better product.
That's not to say that you can't make a great fan controller from scratch. It can be done for very little(most microcontrollers only cost a dollar or two). You just need to have either the right tools and experience or a very strong interest in electronics for it to be a worthwhile project.
Also you can't control the speed of three-wire fans like that. The third wire(yellow) is for monitoring the fan rotation, not controlling it. The only way to control a three wire fan is by regulating the input voltage.
Oh, and it really shouldn't take much more than 100 lines unless you're programming in assembly.
Ugh.... you went and edited in a whole lot more...
You don't want to multiplex PWM. It just doesn't make sense. Run multiple fans on the same channels. If you must have more channels then buy a PWM chip rather than another microcontroller or god forbid another $50 development board.
Aaaand, there's the other side of things. I have an idea of how things will turn out in the end, but I haven't spent too much time figuring out those particular details just yet. I do have an interest in electronics and have some experience with those types of things, but it'll come down to how many useful functions I'll require in the end... We'll see I guess! Thanks for your input! (I DO like those Lamptron FC-6 controllers, mm mm)
Originally Posted by Darkknight512;12476584
I know putting a dev board in a finished product is not recommended. I was making an example, I know you can make bare ATmega board and program them over ICSP for a lot less. Through as a 1 time touching an electronics project it is probably not worth it to grab an ICSP programmer.
I put in 500-1000 lines because I tend to write that much for simple things because I want to do everything and I just keep adding to projects. I don't think you could put in an interface for setting up automated temperature control and actually doing it in then 100 lines.
Yea I made some changes to the post after I realized my mistake in the shower.
Thanks again for clarifying - from what I understand there is quite a large market for enthusiast-level boards with a wide range of capabilities.. I'll have to spend some time researching it I guess!
It's been a while since the last update, but basically, I got around to installing the dado blade on the table saw to make some important cuts for the two cabinets, and was able to do a bit of test fitting.
For those of you not really in the know, a dado blade has two regular saw blades (One for the left, one for the right) and some irregular shaped blades of varying thickness that you put in between, until you get the right width. I'll let the pictures do the talking.
The beauty of using dado blades in the table saw (At least I think) is that you can set it up at the right height and width, and then set the fence to the proper width and do all 3 of your supporting boards one after another so they will be lined up perfectly when it comes time for assembly.
I put 3 cuts in each of the 3 supporting walls of the left-hand cabinet. There was a bit of chipping, I should have probably put down some masking tape, but it's nothing major and will be on the inside anyways.
I threw on a bit of wood filler to patch up the chipped parts, and then let these 3 dry while I worked on the right-hand cabinet cuts.
I then had some time to put together a quick test fitting! Not bad! Some of the wood was just a bit crooked, so I'll have to spend some time with the sander to loosen up some of the dado joints.
This pretty much completes the first phase of the project - I won't have any use for any of the big, messy tools anymore.
All that's really left are a few small detail cuts, some holes need to be cut out, the whole thing needs to be sanded to pre-stain state, and then assembly and staining!
I'll be bringing all of the materials back to my place where I'll be doing just that.