Topic: Custom heated seat controller project

[TomatoSoup]

By request, just a quick thread about my new (touch sensitive) heated seat controller.  Not too many details, but some photos at least...

I've been planning this for quite some time and had designed the circuit and written the microcontroller software last year.  But it took me a long while to get around to raise the energy to design and make the actual buttons.

The controller is fairly simple, it just uses a couple of solid-state relays, one each side, and based on the number of presses, selects one of three heat levels (plus off).  It adjusts the heat by just turning the power to the heating elements on and off at different duty-cycles.  Simple really.  There is a red and blue ganged LED that signals the level selected - red=high, purple=medium and blue=low.

So on to the photos!  This first shows the top and bottom of my home-etched circuit board.  The little surface-mount chip on the bottom is the touch sensor chip, the chip on the top (middle) is the Atmel AVR microcontroller and the two black squares off to the sides are the solid-state relays:

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This shows the heavy sheet of aluminium that I used for the relay heat sink, mounted to the top of the A/C controller - probably overkill since I found the relays barely got warm:

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Then these are the 'innards' of the switch buttons.  At the back is a PCB that supports the backlight and signal LEDs, which is in turn glued to the touch-sensor PCB, in turn glued to the front lens. The lens was cut out of sheet acrylic, shaped and polished.  And the icon made from laser-printed transparency sheet.

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The switch PCB assemblies (above) are inserted into the barrels which are screwed into the bottom of the A/C controller.  Those barrels are (ahem) made from the hollowed-out top caps of two fingernail polish bottles

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Then this shows everything put together and mounted back on the Boomerang...

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And finally, the finished article from the front:

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[Sly Bob]

I love this stuff. Nice elegant solution Mark, looks awesome!   

[Rockchops]

That looks great, well done!!


Sent from an abacus

[ebrown0104]

Looks great, like it should be there from the factory.

[Gentleman Jack]

TS must be one of the least intelligent and useless members we have on this forum.

[Critterman]

So many things could be said here...................


But I will leave it at good Job TS, and thanks for leading the way in electric/electronic projects

[Sly Bob]

What would it cost to make a board like that at home Mark?

[TomatoSoup]

What would it cost to make a board like that at home Mark?

Component cost is pretty low, under $25 (the relays are the most costly part, ~$7 each).  The difficult bit is all the time and effort that goes into the cosmetic and mechanical pieces.

[Sly Bob]

And to make the bare PC board? I haven't made boards since college.

[2kwk4u]

[DeepBlueGXP]

Nice

[JoshMcMadMac]

Absolutely awesome. Well done TS!

[TomatoSoup]

And to make the bare PC board? I haven't made boards since college.

Laser print the track layout on glossy photo paper, iron on to a cleaned piece of copper-clad, soak in boiled-hot water and peel off the paper to leave just the print on the board, soak in Ferric Chloride etcher.  Done.

And you can repeat with a mirror-image of the component layout on the top of the board (but without the etcher, obviously) if you wish.

[Helios]

Wow!

[ChopTop]

Such a cool project. 

[Robotech]

Laser print the track layout on glossy photo paper, iron on to a cleaned piece of copper-clad, soak in boiled-hot water and peel off the paper to leave just the print on the board, soak in Ferric Chloride etcher.  Done.

And you can repeat with a mirror-image of the component layout on the top of the board (but without the etcher, obviously) if you wish.

Okay, this goes so far beyond my level of electronic experiance. Wow TS, great work. You coudl do a how to on just this process alone.

[sallysky]

This looks great TS. I would be happy with the rocker switch if I could get the icon illuminate. How hard would that be to do?

[TomatoSoup]

This looks great TS. I would be happy with the rocker switch if I could get the icon illuminate. How hard would that be to do?

Yeah - you asked this on another thread and I replied there.  Basically impossible.  The switch is not transparent, so you'd have to find a replacement switch that was.  I looked for something suitable and couldn't find ANYTHING that would work.  I even pulled some from other cars in a scrapyard, but they wouldn't fit.  That's why I ended up constructing my own.

[sallysky]

Thanks so much I forgot that I posted that guess I am getting old.

[Sly Bob]

Thanks so much I forgot that I posted that guess I am getting old.

Sure beats NOT getting old...