I had seen a machine (electro-surgical generator) used for surgery purposes; it had a digital interface having 7 segment displays on the front board. It was using a PIC18f452 and a Atmel EEPROM 24C64. What's the use of a microcontroller in such machine? Traditional (electro-surgical generator) machines use knobs and switches; why is the micro-controller actually used?

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    \$\begingroup\$ Well, you need something to crunch your knobs and switches into the 7-segment output :) \$\endgroup\$
    – Dzarda
    Jun 9, 2014 at 19:08

1 Answer 1


There's never a case where you have to have a microcontroller, at least not technically. Anything a microcontroller does can also be done by an appropriate combination of discrete components. What the microcontroller buys you is size and flexibility. The microcontroller does the job in a smaller package than the discrete components (which sometimes makes the difference between practical and not), and can be programmed to do a different job vastly more easily than a discrete component circuit can be redesigned.

There's also the fact that many engineers, especially younger ones, know microcontrollers far better than we know discrete components. I wouldn't know what to do with a 555 timer or a hex decoder or half the parts on the more dusty shelves around here. But I know I can accomplish all those tasks in a smaller chip. So if you asked me to design something like that, it would have a microcontroller just because that's what I know.

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    \$\begingroup\$ And furthermore, a single microcontroller that costs a couple bucks can replace dozens or hundreds of discrete components. The cost advantage can be enormous. \$\endgroup\$
    – Dan Laks
    Jun 9, 2014 at 20:11
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    \$\begingroup\$ Even moderately complicated algorithms can be prohibitively difficult to implement in hardware with discrete components. If you find that some of your components are ROMS and RAMs, and the other are starting to look like they are implementing a fetch-decode-execute cycle, then maybe it's time to reconsider. :) \$\endgroup\$
    – Kaz
    Jun 9, 2014 at 20:54

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