[firethief]

> They address a specific category of low-cost, high volume, non-serviceable products with limited functionality. You need to wait for the push of a button and then let an LED flash exactly five times? You need to control a battery-operated night light? The sub $0.10 MCU is your friend to reduce BOM and shorten development time.

If you're allergic to 555s, I guess?

[HeyLaughingBoy]

The logic you'd need to add to a 555 to flash an LED exactly five times would likely cost more than doing it in an MCU.

[jpindar]

And at the last moment management would ask you if you can make it flash six times.

[throwaway2048]

These are cheaper than 555s, more easily available in various footprints, need almost no supporting passive circuity or glue logic, lower power usage, and more flexible to boot.

Popularity of the 555 waned a long, long time ago.

[thaeli]

More accurate timers, too. It's bizarre to think that "program a microcontroller" is actually cheaper - even in small quantity - than the 555 designs I remember building as a kid.

(In single quantities from LCSC the cheapest 555 is $0.07 and the cheapest Paduak microcontroller is $0.04 - in quantity the 555 is $0.04 and the Paduak is $0.025. Plus fewer support passives with the Paduak.)

[GeorgeTirebiter]

True. This is still cool, tho: https://shop.evilmadscientist.com/tinykitlist/652

[nsxwolf]

For the push button example I can envision using a pair of 555s or a 556 as a timer for the flashing and a latch to store the success condition, but how does it count to 5? You need more logic in here, so why not a cheap programmable chip?

[kragen]

The microcontrollers we're talking about here cost the same as a 555, or less, and don't need external timing components.