4 ms·

Heh, Using a 555 timer for preemptive scheduling in Linux is one of the biggest flexes I've seen in a while.

codeflo 2y ago
For me, the whole thing is an impressive flex, but I know next to nothing about electronics. Can you elaborate what’s interesting about using 555 timers in particular?
- gnunez 2y ago
  The 555 timer is considered one of the most successful chip designs in electronics. It has a simple, well understood, design. The timing on the 555 can be configured to generate a periodic signal using just a few resistors and capacitors. The 555 is often used as a timer in electronic circuits. The Linux scheduler is usually configured to respond to interrupts generated by a cpu. To replace those cpu interrupts by a simple 555 timer is impressive due to the unconventional nature of the setup.
  - javcasas 2y ago
    Also, the 555 is an ancient chip, that pretty much appeared as the basic chip (along with it's friend, the 741 general purpose op-amp), being the two of them the protagonists of pretty much 70% of the hobby circuits in the 80s.
    - deleted 2y ago
      [deleted]
- drewzero1 2y ago
  There's a bit of a meme among electronics hobbyists that for so many projects with an Arduino, somebody in the comments says "I could've done that with a 555”. It's a very common chip with a wide range of uses from arcade sound generation to the timer on a toaster to light/motion activated alarms.
  - pjmlp 2y ago
    As someone that grew up reading Elektor articles, that pretty much sums up most of the gadgets I see on Maker magazines. The big difference is that is much easier to program a microcontroller in software, than mastering electronics, specially when analogue circuits are evolved, and the only debugging tools are a multimeter, pen and paper.
    - drewzero1 2y ago
      I've seen it often on Hackaday over the years, and while they probably could do it all with a 555, I certainly couldn't... My specialties are software and mechanical stuff, for everything in-between I shove in an Arduino and hope it works!
- szundi 2y ago
  There is something about the 555 that triggers love from people
  - unwind 2y ago
    Yeah most chips don't get stuff like a discrete version [1] or a furniture recreation [2]. 1: https://shop.evilmadscientist.com/productsmenu/652 https://shop.evilmadscientist.com/productsmenu/652 2: https://www.google.com/amp/s/www.instructables.com/Giant-555-Footstool/%3famp_page=true https://www.google.com/amp/s/www.instructables.com/Giant-555...
  - BobbyTables2 2y ago
    I see what you did there :->
- phendrenad2 2y ago
  I don't think it's a flex per se, but more of a nod to where many people start off in their electronics careers. The LM555 has been used for four(?) decades to teach electronics to students. A cheap $1 8-pin microcontroller (attiny, avr8, pic) could do the job of an LM555 without the LM555's required capacitors/resistors. But that's not as fun.

For me, the whole thing is an impressive flex, but I know next to nothing about electronics. Can you elaborate what’s interesting about using 555 timers in particular?

gnunez 2y ago
The 555 timer is considered one of the most successful chip designs in electronics. It has a simple, well understood, design. The timing on the 555 can be configured to generate a periodic signal using just a few resistors and capacitors. The 555 is often used as a timer in electronic circuits. The Linux scheduler is usually configured to respond to interrupts generated by a cpu. To replace those cpu interrupts by a simple 555 timer is impressive due to the unconventional nature of the setup.
- javcasas 2y ago
  Also, the 555 is an ancient chip, that pretty much appeared as the basic chip (along with it's friend, the 741 general purpose op-amp), being the two of them the protagonists of pretty much 70% of the hobby circuits in the 80s.
  - deleted 2y ago
    [deleted]
drewzero1 2y ago
There's a bit of a meme among electronics hobbyists that for so many projects with an Arduino, somebody in the comments says "I could've done that with a 555”. It's a very common chip with a wide range of uses from arcade sound generation to the timer on a toaster to light/motion activated alarms.
- pjmlp 2y ago
  As someone that grew up reading Elektor articles, that pretty much sums up most of the gadgets I see on Maker magazines. The big difference is that is much easier to program a microcontroller in software, than mastering electronics, specially when analogue circuits are evolved, and the only debugging tools are a multimeter, pen and paper.
  - drewzero1 2y ago
    I've seen it often on Hackaday over the years, and while they probably could do it all with a 555, I certainly couldn't... My specialties are software and mechanical stuff, for everything in-between I shove in an Arduino and hope it works!
szundi 2y ago
There is something about the 555 that triggers love from people
- unwind 2y ago
  Yeah most chips don't get stuff like a discrete version [1] or a furniture recreation [2]. 1: https://shop.evilmadscientist.com/productsmenu/652 https://shop.evilmadscientist.com/productsmenu/652 2: https://www.google.com/amp/s/www.instructables.com/Giant-555-Footstool/%3famp_page=true https://www.google.com/amp/s/www.instructables.com/Giant-555...
- BobbyTables2 2y ago
  I see what you did there :->
phendrenad2 2y ago
I don't think it's a flex per se, but more of a nod to where many people start off in their electronics careers. The LM555 has been used for four(?) decades to teach electronics to students. A cheap $1 8-pin microcontroller (attiny, avr8, pic) could do the job of an LM555 without the LM555's required capacitors/resistors. But that's not as fun.