hey guys atm im in the planning stage of a complete scratch build, and was wandering if anyone had any experience in using the qslide or the qwheel from quantum? I want to build a fan controller from scratch either of these chips to control the fan speed and a led display. I have some skills in electronics but this is a little beyond me. any suggestions or advice would be invaluable. thanks Pooleo
Well, the circuit schematic for the q wheel looks simple enough from the q touch site, but the hard part is interfacing with its SPI interface. This can be bit-banged from even slow microcontrollers, so this shouldn't be too much of a problem. What microcontroller are you planning on using?
I have no idea! It is a little ambitious this one, but something I would really love to get going! Does anyone have any suggestions on an spi microcontroller that I could use? ZapWizard did something on Project redwood a while back, but there was not much detail on the qwheel side of things.(ace project btw!!!) This mod is part of a much much bigger project, that will be posted as soon as the aluminium extrusions I ordered show up!!!!!!!!!! Thanks
I'm sure you'll get a variety of opinions on this one... Me, I seem to have fallen into the Atmel AVR (wiki) camp because they are so easy to use and cheap to boot. You can build your own parallel port programmer with just a couple of parts (example). Plus, if your C isn't the sharpest (like mine), there's a great Basic compiler at Bascom that has simple, easy-to-use spi routines; their free demo allows for 4K of code which is enough to accomplish many projects. Of course, there are many asm and C compilers available as well, both free and commercial. I'm sure other platforms like the Microchip PIC are probably useable as well, but for me the AVR was soooo easy to get started with and was more than capable for my needs I just never left. I can't compare performance based on compiled code, but hardware-wsie I think the AVR's offer more performance per clock than the PIC's as well. [edit] btw, as I'm new here, I just went back to check out the ZapWizard's Redwood project that you refer to (excellent work!). It looks like he used a qTouch chip that has direct outputs, so no spi was needed. [edit 2] OK, I see where ZapWizard used the qWheel... he used a 6811 controller to interface the spi to rs232 for communication to the pc. This could also be accomplished with the avr and Bascom I mentioned above (perhaps even more easily, but prior knowledge and comfort with a specific platform do count for something). In any case, you would have to research the qWheel datasheets to gain an understanding of the commands used to control it and how the data returned from it is structured.
you can get QPRox QTouch ICs that give direct outputs in up to four buttons, the rest use SPI or similar interfaces. for micros i would go with a PIC Microcontroller with the CCS PIC Compiler
thanks for all the suggestions guys. My C is appalling, and my basic is going to be a little rusty! lol. Thank god my step dad is not bad at basic programming! might have to go and ask for his help on this 1!!!! AVR does look fairly impressive i have to say. going to trawl through the qwheel datasheet and see what it says! hopefully this project might see the light of day or the bit tech forum
Out of curiosity I Googled around for info on interfacing to a common Synaptics Touchpad (found in many dead laptops or for cheap on ebay). Although not quite exactly the same as the wheel, it might be close enough given that you might be able to obatin one for free or dirt cheap. Granted the Qwheel chips themselves aren't that expensive, but the nice development boards that save you from making a custom pcb are $90+ (boy can you tell these things are marketed towards businesses; that's just crazy expensive for a simple pcb and some cheesey test app that's probably only a re-hash of some MS kb article). I'm still researching this, but it looks like they come with either conventional ps2 or more technical spi interfaces. Either way, maybe a workable alternative? Just thought I'd throw this in the mix. Links so far: http://www.synaptics.com/decaf/utilities/ACF126.pdf http://www.mp3car.com/vbulletin/showthread.php?t=32899 [edit] New here, so I keep forgetting to search Several threads here regarding touchpads... [edit 2] btw, the Bascom Basic compiler has ps2 interfacing options as well, so theoretically you could interface a simple ps2 touchpad to an avr, and have the avr control the fans and led display. Oh, and I like to edit... memory isn't what it used to be
I would personaly use a picaxe, since they need no extra parts to programs them (Well, 2 resistors) they are dirt cheap (£4 max) and you can program them really easily. There are many examples of how to interface them with spi devices (Some natively, some through bit-banging) It really comes down to what you are happiest with - although everyone has their favorite chip, they all are fairly similar. Would you be able to post your source code if you manage it, I am planning on doing something similar.
fwiw I just had another thought regarding using a touchpad... conceivably you could have the pad segregated into different horizontal or vertical zones, where each zone would control a different fan. Don't know if this fits into your vision of the project, but I figured I toss it in the mix... I have a dead Dell Inspiron 1100 (with touchpad), I think I might just look into this a bit further when I get home today. [edit] Kind of like what they are doing here with led lighting (a pretty cool project in it's own right!)
