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Grogster

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Joined: 31/12/2012
Location: New Zealand
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Posted: 12:19pm 10 Sep 2014

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HA! - Got you!

You thought this was about one already done - sorry.

I am looking into this though, as little toaster ovens are quite cheap these days, and I was thinking along the lines of bypassing the thermostat on the oven, and have a MicroMite controller in it's place.

This leads itself to using an LCD with the easy LCD commands on the uM chip, and some basic keys, so you can set the pre-heat and reflow temperatures along with the cool-down, all into one nice little oven.

Other then the uM chip, we'd need a thermocouple for the oven temp sensor, an LCD display, some buttons and a main-rated relay to switch the oven elements on and off.

Do-able me thinks - anyone else done this already by any chance?
(I see plenty of videos on YouTube of people using toaster ovens like this, but we could use our child prodigy - the MicroMite chip for the controller!)

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Zonker

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Joined: 18/08/2012
Location: United States
Posts: 767

Posted: 01:24pm 10 Sep 2014

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Hay Grogs...

Seems like this controller would be the perfect fit for the new LCDuMite board..!
Lou sent some to Phil and he has them for sale... I heard he should be fitting them with 170's, so it would have the extra room if needed... Also the IR stuff seems to work ok, so you could use a remote to control it and skip the keyboard...

I will be posting the Gerber artwork for "rev B" this weekend... This fixes 2 errors from the first run of boards that Lou had ordered from Itead, one was a stupid wiring error on the temp chip pull-up resistor.. (somehow I connected it to GND).. the other error was a stacking error on the SOH (sea-o-holes) board with the power in barrel connector running into R4 (the LCD contrast pot) when you stack the boards together.... All has been fixed now...Edited by Zonker 2014-09-11

Grogster

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Posted: 01:38pm 10 Sep 2014

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Cool - where can I read about Lou's board?

Always easier to use a proven design, then have to re-design the wheel, if you know what I mean!

Yes, totally agree that IR would be the way to do it - no buttons then, just an LCD window and IR receiver hole.

EDIT: Found it. Not sure how I missed that one. So WhiteWizard sells them(aka Phil)?Edited by Grogster 2014-09-11

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viscomjim
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Joined: 08/01/2014
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Posted: 10:25am 15 Sep 2014

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Here is an article on the reflow oven with controller running picbasic pro, with pid control. This could be a great start for a uMite controlled oven.

ReFlow oven pbp

Grogster

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Posted: 12:53pm 15 Sep 2014

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Thanks for the link.

Smoke makes things work. When the smoke gets out, it stops!

viscomjim
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Posted: 02:39pm 15 Sep 2014

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Grogster, no problem. I am checking out how he implemented the pid and such, but this looks like a good starting point. I bet the uMite will be a great controller for this project. The surface mount thing was always a bit scary for me, but after watching quite a few youtubes on this method, it really seems very doable and not so scary. The thread on the qfn version of the pic32 made me want to start investigating this. Should be a fun road. I have a feeling that this thread may get big. (I hope).

EDIT....

Make sure you take a look at his GITHUB page as there is a software bug fix that seems relatively important.Edited by viscomjim 2014-09-17

Grogster

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Posted: 03:05pm 15 Sep 2014

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What always frightened me a bit about reflow oven, WAS the temperature.
Most IC's etc state that their maximum operating temperature is about 125'C or so, yet you bake the parts up to 230'C or so - you'd think that you'd kill the parts just by heating them up that much in the first place.

However, the same as you, I have watched lots of videos on YouTube etc of people doing this kind of thing with great sucess for the most part.

I was even watching someone hot-air reflow a QFN part the other day, so I guess if they can do it........

QFN, being contact really on the bottom of the package only, does need hot-air or oven to solder them, and this is exactly what I want to play with, so it will be a good learning curve for me as well as anything else!

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bigmik

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Joined: 20/06/2011
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Posted: 05:55pm 15 Sep 2014

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Grogster said
QFN, being contact really on the bottom of the package only, does need hot-air or oven to solder them,

The drawing of the QFN '170 part I looked at on MChip showed the pad was bottom and slightly up the side. sort of like the SMD 47uF cap. I reckon should be hand solderable..

Mick

Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<<

Grogster

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Posted: 06:12pm 15 Sep 2014

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I will confirm that for you when my chips arrive - they will probably be here in the next day or so.

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