Author Topic: A small microcontroller with a digital and analog i/o. (Read 3540 times)

Hawaii00000 · « **on:** March 21, 2009, 05:01:05 PM »

Does anyone know of a small microcontroller thats no a PIC? It only needs one analog and one digital i/o. the key part is it needs to be kinda small.

SmAsH · « **Reply #1 on:** March 21, 2009, 05:04:27 PM »

are you happy to experiment with smd's? theyre small enough. what do you need it for? how much do you want it to cost?

Soeren · « **Reply #2 on:** March 21, 2009, 07:13:09 PM »

Quote from: Hawaii00000 on March 21, 2009, 05:01:05 PM

Does anyone know of a small microcontroller thats no a PIC?

Why do you not want a PIC??

Quote from: Hawaii00000 on March 21, 2009, 05:01:05 PM

It only needs one analog and one digital i/o. the key part is it needs to be kinda small.

Nothing beats the PIC10F222 in size, it's in a SOT-23 housing (like a regular SMD transistor, just with 3 pins each side.

SmAsH · « **Reply #3 on:** March 21, 2009, 07:16:22 PM »

Quote from: Soeren on March 21, 2009, 07:13:09 PM

Why do you not want a PIC??

programming language preference? a grudge? never used pics?

Razor Concepts · « **Reply #4 on:** March 21, 2009, 08:30:55 PM »

attiny25, attiny85 etc has 5 i/o including digital and adc

All in an 8 pin package, dip for testing and SMD for final product.

galannthegreat · « **Reply #5 on:** March 21, 2009, 09:17:53 PM »

MEGABitty is a full MCU board that is less than a square inch: http://www.junun.org/MarkIII/Info.jsp?item=49

Hawaii00000 · « **Reply #6 on:** March 22, 2009, 12:40:48 AM »

Quote

are you happy to experiment with smd's?

Could you explain what an smd is?

Quote

Why do you not want a PIC??

I don't wanna have to learn basic. I want to program in C.

Quote

MEGABitty is a full MCU board that is less than a square inch: http://www.junun.org/MarkIII/Info.jsp?item=49

It looks good but it needs to be assembled, and I'm very far from being a soldering expert

SmAsH · « **Reply #7 on:** March 22, 2009, 12:51:44 AM »

smd is a surface mount component. y'know like those really little chips. look at the axon, mostly everything on there is smd! they tend to save space but are harder to solder if you have an unsteady hand like me

Hawaii00000 · « **Reply #8 on:** March 22, 2009, 01:05:58 AM »

Are they the flat, square ones that have really small pins?

arixrobotics · « **Reply #9 on:** March 22, 2009, 01:32:11 AM »

You dont have to program PICs in BASIC. I do it in C.

SmAsH · « **Reply #10 on:** March 22, 2009, 01:43:45 AM »

what compiler do you use?

Soeren · « **Reply #11 on:** March 22, 2009, 06:02:08 AM »

Hi,

Quote from: Hawaii00000 on March 22, 2009, 12:40:48 AM

Could you explain what an smd is?

SMD, not smd, it's an acronym (so should be "upper case") for Surface Mount Device.

Quote from: Hawaii00000 on March 22, 2009, 12:40:48 AM

Quote
Why do you not want a PIC??
I don't wanna have to learn basic. I want to program in C.

You can program PICs in:

BASIC (an acronym again - Beginners All-purpose Symbolic Instruction Code).
C
Assembler
Pascal
Logo
Prologue
Ada
Forth
JAL (Just Another Language)
PICL

And a host of other languages and variations thereof.
Like the C compiler variant that I have, with a drag and drop interface where you can do maybe 80% to 95% of most apps by reusing timer set-ups, keyboard routines etc. and then finish off text-vise - (not that I really use it very often though).

TrickyNekro · « **Reply #12 on:** March 22, 2009, 09:16:54 AM »

I use ATtiny13 for such purposes....think of it as an option...

Soeren · « **Reply #13 on:** March 22, 2009, 09:26:51 AM »

Hi,

Here is a size comparison:

The chip on the PCB is a PIC10F2xx and the board will fit in a regular 8 pin dip housing (like the ATtiny13).

Hawaii00000 · « **Reply #14 on:** March 22, 2009, 06:48:22 PM »

Are the ATtiny and PIC about the same size?

Razor Concepts · « **Reply #15 on:** March 22, 2009, 06:50:48 PM »

Yes. The attiny is a hair longer (by like 1mm on the SMD package) because it has 8 pins instead of the PIC's 6 pins.

Hawaii00000 · « **Reply #16 on:** March 22, 2009, 07:23:45 PM »

Ok, I think I'll go with the ATtiny. Does anyone know of a good example for the wiring? Would it be similar to the $50 robot board?

SmAsH · « **Reply #17 on:** March 22, 2009, 11:24:34 PM »

google for a datasheet for it. then you probibly could wire it like the $50 robot but with less i/o

Soeren · « **Reply #18 on:** March 23, 2009, 05:09:04 AM »

Hi,

Quote from: Razor Concepts on March 22, 2009, 06:50:48 PM

Yes. The attiny is a hair longer (by like 1mm on the SMD package) because it has 8 pins instead of the PIC's 6 pins.

With SMDs, it's all about area!

SO-8 = 30mm^2
SOT23 = 7,5mm^2 (i.e. 1/4 of ATtiny)
2X3 DFN = 6mm^2 (i.e. 1/5 of ATtiny)

PIC10F2xx comes in the latter two packages (and in a DIP8 if needed).

galannthegreat · « **Reply #19 on:** March 23, 2009, 11:38:46 AM »

Good tip for soldering SMD parts is first ALWAYS tin one of the pads you need to secure a component to, so then all you'd need is a helping hands sort of thing to hold the board a nice pair of fine tweezers, fine tip on your iron and above all, patience, it is a virtue you need to have to do this.

SmAsH · « **Reply #20 on:** March 23, 2009, 12:56:06 PM »

and flux helps, has anyone else tried the method where you apply flux to the first pad solder it in and secure it then apply flux and solder onto a desoldering braid and melt that solder onto the chip legs?

galannthegreat · « **Reply #21 on:** March 23, 2009, 02:10:06 PM »

Yes it does work, but make sure that you do not put flux over multiple pads at a time, especially if they are small, this will cause a very annoying bridge between pads. But overall I've found that a good method for solder SMD chips. You even stick small amounts of silicone on places where components go to hold them down for soldering.

SmAsH · « **Reply #22 on:** March 23, 2009, 02:38:56 PM »

or blu-tack underneath. ive been wanting to get into SMD more than i am now. i barly use them at all. mainly because nobody near me sells them much.

Razor Concepts · « **Reply #23 on:** March 23, 2009, 03:10:03 PM »

An easy way is to just tin all the pads, put the SMD chip on and just cover all the pins with solder. Use solder wick to get rid of excess and you have a perfectly soldered chip.

SmAsH · « **Reply #24 on:** March 23, 2009, 03:14:12 PM »

ill have to try that one sometime. and does anyone know of a place that is in aus or has cheap shipping to aus that offers SMD resistors and leds caps...etc things like that. i can already get SMD microcontrollers from futurlec but i cant really find many SMD? can anyone help?

Hawaii00000 · « **Reply #25 on:** March 23, 2009, 09:47:25 PM »

Last time I tried to use a desoldering braid it didn't work. I was using it on a factory manufactured board so maybe my soldering iron didn't get hot enough to melt the special solder they use.

Razor Concepts · « **Reply #26 on:** March 23, 2009, 09:52:14 PM »

Chances are the "factory" solder is lead-free which takes a lot more energy to melt than leaded solder.

SmAsH · « **Reply #27 on:** March 23, 2009, 11:42:31 PM »

it does? wow never knew that before!

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Author Topic: A small microcontroller with a digital and analog i/o. (Read 3540 times)

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