Author Topic: need VERY tiny microcontroller (Read 7684 times)

Admin · « **on:** May 18, 2007, 10:45:41 AM »

Can anyone recommend a microcontroller that is smaller than .7cm in width/height (any length is OK), including pin spread and wire tracing to connect it up?

Unfortunately Digikey lists 17274 microcontrollers and has no ability to search by size $:-\$

I just need a single timer, at least 4 PWM or D/O (more the better), and at least 2 ADC. Memory size and part cost are no concern.

As always, I ask weird questions, and Im not allowed to talk very much about the application . . . sorry!

hgordon · « **Reply #1 on:** May 18, 2007, 11:14:36 AM »

Philips/NXP LPC2103 body size is 7mm x 7mm x 1.4mm and has the features you describe. It's a QFP package, so the lead extend out, but you could bend them down and mount through holes drilled in your mounting substrate.

http://www.standardics.nxp.com/products/lpc2000/pdf/lpc2101.lpc2102.lpc2103.pdf

Admin · « **Reply #2 on:** May 18, 2007, 11:45:27 AM »

Ill probably be using a thin flexible PCB.

I didnt realize how advanced the tiny sized microcontrollers have gotten . . . its about 7.2mm, or 9mm with pins sticking out. Not sure if I can get the traces in there . . .

But its really close to my specs so Im not going to rule it out.

I guess that brings me to 2 new questions:
Whats the best way to solder something like that? (aka what equipment should I buy?)
How do I program that thing in circuit? I see it has MISO/MOSI stuff similar to AVR . . .

JonHylands · « **Reply #3 on:** May 18, 2007, 11:58:32 AM »

I use the ATmega168 in MLF-32 form, which is 5mm square, with the pins tucked underneath.

http://www.huv.com/blog/uploaded_images/IMU-04-750971.jpg

The board in that picture is 1.15" x 0.75"...

- Jon

Rolf · « **Reply #4 on:** May 18, 2007, 12:27:17 PM »

Many of the Atmel AVR microcontrollers are very tiny. I think you can choose from many AVR MCs within your specifications. I have recently made a few orders from futurlec. They have very reasonable prices, and ship within a day or two. They also have a wide variety of AVR MCs.
http://www.futurlec.com/ICAtmel.shtml

Admin · « **Reply #5 on:** May 18, 2007, 12:38:17 PM »

perfect! thanks! AVR it is then.

Brandon121233 · « **Reply #6 on:** May 19, 2007, 11:45:03 AM »

Jon did you make or oder that PCB? I'm guesing you ordered it but that looks pretty sweet!

JonHylands · « **Reply #7 on:** May 19, 2007, 02:00:42 PM »

I designed it, and had a prototype printed (one of the yellow ones, with no soldermask or silkscreen). After that, I made a few changes to the design, and had 100 copies of the board printed with the full soldermask and silkscreen.

Its a control board for a 6-axis IMU for the Bioloid robot kit. I plan to start selling them soon, as soon as I get a bunch of other higher-priority stuff out of the way.

- Jon

Admin · « **Reply #8 on:** May 21, 2007, 07:55:41 AM »

Ok now I need a tiny tiny battery to power everything . . . I can put many in series so power isnt the issue, but width/height both must be under 1cm.

The closest I can find is this guy:
http://www.powerstream.com/ultra-light.htm

Unfortunately it measures 1.5cm x 1.5cm which is way too big $:-\$

Voltage should be around 3.6V so I can power the microcontroller . . . suggestions?

Rolf · « **Reply #9 on:** May 21, 2007, 08:05:47 AM »

I have never seen a rechargeable battery smaller than that. The site also says "NEW: The smallest rechargeable battery in the world at 500 mg".

If you dont need the battery to be rechargeable you can always go with a series of watch-batteries.

JonHylands · « **Reply #10 on:** May 21, 2007, 08:33:21 AM »

http://www.bsdmicrorc.com/productDetails.cfm?ProdID=10434&catID=10001

The guy who just made a pico-bot uses them, and he managed to squish it into 12.5mm space...

http://www.poor-robot.com/pico/

At the bottom of that page:

"There is talk of a 5 mAh Li-Poly in the works too."

You might want to cross-post on one of the micro-flyer forums, since they are the guys driving these tiny Li-Poly batteries...

- Jon

dunk · « **Reply #11 on:** May 21, 2007, 08:38:23 AM »

so do you have a maximum length requirement?
AAA batteries are definitely less then 1cm round and you can get rechargeable ones.

dunk.

Admin · « **Reply #12 on:** May 21, 2007, 08:43:36 AM »

Thanks for the idea Rolf!

Ok so I did a search on battery watches and found this list of battery dimensions. The mAh arent correct, but apparently there is some kind of standard that matches dimensions that I can use.

Anyway, apparently the watch battery number CR927 has dimensions of 9.5mm x 2.7mm. I found one that is rated for 150mAh at 3V, and is a rechargeable lithium!

http://www.quality-items-flashlights.com/product_info.php/info/p11781_Coast--LED-Lenser--CR927-Lithium-battery-for-Coast-LED-Lenser-flashlights.html/XTCsid/34332826308e317eecac8efbcf766fac

Quote

You might want to cross-post on one of the micro-flyer forums, since they are the guys driving these tiny Li-Poly batteries.

Does anyone recommend one?

Quote

so do you have a maximum length requirement?

Yes and no. For now lets say no, but length could hinder mobility if its excessive.

Quote

AAA batteries are definitely less then 1cm round and you can get rechargeable ones.

hmmmm apparently it isnt:
http://www.batteryspecialist.com/Merchant2/size-aaa-dim.html

JonHylands · « **Reply #13 on:** May 21, 2007, 10:49:31 AM »

Quote from: Admin on May 21, 2007, 08:43:36 AM

Anyway, apparently the watch battery number CR927 has dimensions of 9.5mm x 2.7mm. I found one that is rated for 150mAh at 3V, and is a rechargeable lithium!

You won't be able to pull more than a couple mA from a battery like that. Look into AAAA batteries as well - they are not common, but there are places that sell them, and they are under 10mm...

http://en.wikipedia.org/wiki/AAAA_batteries

- Jon

maverick monk · « **Reply #14 on:** June 10, 2007, 09:00:28 PM »

i got your realy realy small battery right here, if you cant find them whole sale, ill tell you were you can get them, I have no metric ruler, but I pulled a gp 7AAAHR2A
Battery out of a Zip Zap SE ( the one with lights), its 3/8 inch Diameter and its a pack of 2 cells ( for 2.4 volts) thats 3/4 inch long, so thats 3/8 inch per cell, each Zip Zap SE has 1 2-cell in it, right below the circut board
160mah.

robotvisionary · « **Reply #15 on:** July 09, 2007, 10:14:53 PM »

Quote from: Admin on May 21, 2007, 07:55:41 AM

Ok now I need a tiny tiny battery to power everything . . . I can put many in series so power isnt the issue, but width/height both must be under 1cm.

The closest I can find is this guy:
http://www.powerstream.com/ultra-light.htm

Unfortunately it measures 1.5cm x 1.5cm which is way too big $:-\$

Voltage should be around 3.6V so I can power the microcontroller . . . suggestions?

Wow that is really small. the smallest battery i know in the stores is the one they use in earbuds or the flat ones they are also rechargeable. You can get them at you local radioshack.

KambeiX · « **Reply #16 on:** July 10, 2007, 11:11:34 AM »

you could try molding a LiPo. after all, one of the advantages of LiPo is that you can give them any form you want.

Soeren · « **Reply #17 on:** July 13, 2007, 08:38:50 AM »

Hi,

Too bad Fairchild discontinued their, relatively young, ACE microcontroller family - since they had seriously small outlines like can be seen http://d116.com/ace/.
Actually, it's still possible to get some of the family members, so if you need ultra small, might be worth a look.

For a small battery, zinc-air button cells are pretty impressive primary cells - The largest is a P675, which is the exact size of an AG10 button cell (the size used in many LASER pointers and what not), but with a capacity ranging from 600 mAh to 680 mAh (differs between manufacturers).
However, zinc-air has to be used within a month or two from when they are "primed" with air (by removing the adhesive tab on the back, exposing tiny holes for the air) - and no, re-taping an allready primed cell won't change that.

Hey, I'm getting "naughty" ideas while writing this, since I throw away dozens of good cells regularly, some just because they're close to their expiry date - why not make a couple of tiny desktop robots/battery exhausters - I'm sure the kids among my patients would like such a scenario

paulstreats · « **Reply #18 on:** July 13, 2007, 05:22:48 PM »

Quote from: Soeren on July 13, 2007, 08:38:50 AM

Hi,

Too bad Fairchild discontinued their, relatively young, ACE microcontroller family - since they had seriously small outlines like can be seen http://d116.com/ace/.
Actually, it's still possible to get some of the family members, so if you need ultra small, might be worth a look.

For a small battery, zinc-air button cells are pretty impressive primary cells - The largest is a P675, which is the exact size of an AG10 button cell (the size used in many LASER pointers and what not), but with a capacity ranging from 600 mAh to 680 mAh (differs between manufacturers).
However, zinc-air has to be used within a month or two from when they are "primed" with air (by removing the adhesive tab on the back, exposing tiny holes for the air) - and no, re-taping an allready primed cell won't change that.

Hey, I'm getting "naughty" ideas while writing this, since I throw away dozens of good cells regularly, some just because they're close to their expiry date - why not make a couple of tiny desktop robots/battery exhausters - I'm sure the kids among my patients would like such a scenario

There is also a link to a potato powered web server on the link above

This is very funny and made me laugh for quite a while!

Battery exhausters... sounds like some fun projects up ahead! Also can use up spare components

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Author Topic: need VERY tiny microcontroller (Read 7684 times)

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