What is the simplest way to make a small low power and low price circuit that flashes LED's

Question

I am wanting to make a small handheld circuit that could flash anywhere between 4-6 leds in a programmed order. It has to be as small as possible and use very little energy. I am trying to make these cheap enough that I can make a lot.

I was thinking about using one of the AVR series mcu.

Size wise I was thinking of having it run on triple A'S. I am open to suggestions.

Edit I am looking for DIP MCUs not smd.

Answer 1

Depending on how programmable/complex your flashing is - you may be able to do it without software. In which case:

Most Simple Stoplight circuit

Blink an LED with just a capacitor?

If you do need to use a microcontroller - with 6 I/O pins which is low power and small then I'd look at:

MSP430 (Value Line). Here's an app note on powering an MSP430 from a single cell (using a charge pump). There's also now an MSP430 which runs at 0.9V.

AVR PicoPower is also worth a look. Even the ATMega168/328 used in Arduino though can be put into quite low power modes.

Here's a couple of Arduino libs to do it:

http://code.google.com/p/narcoleptic/

http://www.arduino.cc/playground/Code/Enerlib

Answer 2

Have you looked at the MSP430G2231? It's really low power and is pretty cheap too. Plus it isn't a SMD MCU.

Answer 3

if you want cheap you dont even need a micro controller for simple on/off. Infact i would avoid them alltogether. a Simple sequence of leds that repeat you could use a simple 555 timer and a counter module, i cant think off which ones off the top of my head but there are lots of option and would take some time to plow through data sheets.

Answer 4

You might also look at the MiniPOV. It's the simplest, smallest, and lowest-cost way to flash LEDS with a microcontroller that I've ever seen. But I'm sure you can find some way to "trim the fat" on this project :-).

• MiniPOV 1
• MiniPOV v2
• MiniPOV v3 has a parts list that links directly to a distributor of each part
• MiniPOV discussion forum
• MiniPOV 3 kit for sale -- note that this price does not include an outer case or batteries, which could easily double the materials cost of this item.

I've been told that lots of designers find it easier to make a new system when they can start with a "scaffolding" of a known-working system, even when they end up completely changing everything so there isn't any part of the scaffolding remaining.

Using a microcontroller for a simple LED sequencer seems like overkill, but any alternative I can think of requires more than 1 components to replace the 1 microcontroller chip -- and how can "more components" be simpler?

Answer 5

Have you seen the Throwie that blinks in Morse code? Instructables and Ward's own website. It uses an 8 pin DIP microcontroller (less than $3 in ones).