Week 2.5 – Flashing a LED without a Micro

555 Timer
iCircuit Logo
iCircuit Logo

In Week 2 we made a single LED blink using an Arduino, now about 99.9% of the time this would be overkill (the 0.1% of the time is when you are learning); actually tell a lie, There is a VERY good reason to flash a LED with a micro, but I will cover that later.

To flash an LED we can use a 555 timer:

Introduced in 1972 by Signetics, the 555 is still in widespread use due to its low price, ease of use, and stability. It is now made by many companies in the original bipolar and in low-power CMOS technologies. As of 2003, it was estimated that 1 billion units were manufactured every year. The 555 is the most popular integrated circuit ever manufactured.

The circuit is fairly simple:

The supporting components are:

  • One small cap
  • Two resistors

So the bom1 price is about 35p if you buy from Farnell.

  1. Bill of Material

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