5 ms·

You can easily build some of these circuits with very low investment. The ICs (555; 4017; ...) for circuits like the "LED sequencers" are very cheap (less than

You can easily build some of these circuits with very low investment. The ICs (555; 4017; ...) for circuits like the "LED sequencers" are very cheap (less than $1/1€ each). With ICs in DIP packages [0], the circuits can be built on breadboards [1] since the pins can be inserted directly into the holes of the breadboards. If you are new to this then you can find an overview of electronic symbols in Wikipedia [2] for example - this is helpful because it gives you names and terms to search for. Having even a cheap multimeter to measure voltages, resistances or the polarity of diodes is better than nothing btw (but better don't use these to measure line/mains power - even if they claim to be able to do that). Have fun! [0] https://en.wikipedia.org/wiki/Dual_in-line_package https://en.wikipedia.org/wiki/Dual_in-line_package [1] https://en.wikipedia.org/wiki/Breadboard https://en.wikipedia.org/wiki/Breadboard [2] https://en.wikipedia.org/wiki/Electronic_symbol https://en.wikipedia.org/wiki/Electronic_symbol

kragen 4y ago
According to https://yaqwsx.github.io/jlcparts/ https://yaqwsx.github.io/jlcparts/ the NE555DR costs 11.98¢ but of course not in a DIP. That's about as much as four Padauk microcontrollers these days—if you can find those in stock somewhere. JLCPCB doesn't include the CD4017 in their "basic parts" list; Digi-Key has them for 52¢ but doesn't have a DIP version in stock, just an SOIC. The other night I took apart my cheap multimeter which claims "1000 V" and found no creepage clearance between the traces on the board. So far I haven't died measuring mains power with it but I don't think I'll do that anymore...
- buescher 4y ago
  555 timer is a sub-10-cent part in quantity. Digi-key even has the NE555P in stock for 40 cents onesies and 11 cents in 2500 unit orders. And there's a parts shortage on, if you haven't looked lately. Yeah, don't use cheap tools when your life is on the line.
  - kragen 4y ago
    Yeah, it's 8.87¢ in quantity 50. That's still the cost of two Padauk microcontrollers.
    - asddubs 4y ago
      so what's your point? people should be buying a reel of one time programmable microcontrollers that you'll have to program in an esoteric language in a proprietary toolchain and a programmer that costs more than 8 cents? Or put together one of those open hardware programmers themselves? I mean the padauk stuff is not really a very beginner friendly environment, and it's not as cheap to get going once you consider the accessories needed. just buying and re-using an arduino or a knockoff for a couple dollars would probably be better if you wanted to make the case that a microcontroller is a better place to start.
      - kragen 4y ago
        I had several points: 1. For jellybean ICs "less than [US]$1" understates the case by about an order of magnitude; it's less than [US]$⅒. 2. Other ICs mentioned like the CD4017 have ceased to be jellybean parts and have become esoteric specialty parts, but they're still less than US$1, if you can find them. 3. The reason for this is that, as microcontrollers have gotten cheaper and more capable, the range of circuits for which they are a good fit has grown enormously, and in particular covers just about every circuit where you'd use a CD4017. And once you have a microcontroller in your circuit you probably don't need a 4017 or a 555 because you can usually replace them with 1–5 lines of code. 4. Probing line power with a questionable-quality multimeter really is dangerous. Does that clarify? I agree that Arduino is a much more beginner-friendly environment, even more so than quasi-analog DIPs in a breadboard, and also that the programmer hardware for the Padauk μCs is a significant obstacle.
    - buescher 4y ago
      Sorry, for some reason I saw $11, not 11 cents and thought you were looking at a broker site at a very particular part. The biggest reason I wouldn't use Padauk microcontrollers is that they're not available in north american distribution. I personally really don't get the 555 timer love - almost anything people would do with one for a small design with no firmware, I would use an lm339 type quad comparator. They are great for detecting the presence/absence of pulses though.

kragen 4y ago

According to https://yaqwsx.github.io/jlcparts/ https://yaqwsx.github.io/jlcparts/ the NE555DR costs 11.98¢ but of course not in a DIP. That's about as much as four Padauk microcontrollers these days—if you can find those in stock somewhere. JLCPCB doesn't include the CD4017 in their "basic parts" list; Digi-Key has them for 52¢ but doesn't have a DIP version in stock, just an SOIC. The other night I took apart my cheap multimeter which claims "1000 V" and found no creepage clearance between the traces on the board. So far I haven't died measuring mains power with it but I don't think I'll do that anymore...

buescher 4y ago
555 timer is a sub-10-cent part in quantity. Digi-key even has the NE555P in stock for 40 cents onesies and 11 cents in 2500 unit orders. And there's a parts shortage on, if you haven't looked lately. Yeah, don't use cheap tools when your life is on the line.
- kragen 4y ago
  Yeah, it's 8.87¢ in quantity 50. That's still the cost of two Padauk microcontrollers.
  - asddubs 4y ago
    so what's your point? people should be buying a reel of one time programmable microcontrollers that you'll have to program in an esoteric language in a proprietary toolchain and a programmer that costs more than 8 cents? Or put together one of those open hardware programmers themselves? I mean the padauk stuff is not really a very beginner friendly environment, and it's not as cheap to get going once you consider the accessories needed. just buying and re-using an arduino or a knockoff for a couple dollars would probably be better if you wanted to make the case that a microcontroller is a better place to start.
    - kragen 4y ago
      I had several points: 1. For jellybean ICs "less than [US]$1" understates the case by about an order of magnitude; it's less than [US]$⅒. 2. Other ICs mentioned like the CD4017 have ceased to be jellybean parts and have become esoteric specialty parts, but they're still less than US$1, if you can find them. 3. The reason for this is that, as microcontrollers have gotten cheaper and more capable, the range of circuits for which they are a good fit has grown enormously, and in particular covers just about every circuit where you'd use a CD4017. And once you have a microcontroller in your circuit you probably don't need a 4017 or a 555 because you can usually replace them with 1–5 lines of code. 4. Probing line power with a questionable-quality multimeter really is dangerous. Does that clarify? I agree that Arduino is a much more beginner-friendly environment, even more so than quasi-analog DIPs in a breadboard, and also that the programmer hardware for the Padauk μCs is a significant obstacle.
  - buescher 4y ago
    Sorry, for some reason I saw $11, not 11 cents and thought you were looking at a broker site at a very particular part. The biggest reason I wouldn't use Padauk microcontrollers is that they're not available in north american distribution. I personally really don't get the 555 timer love - almost anything people would do with one for a small design with no firmware, I would use an lm339 type quad comparator. They are great for detecting the presence/absence of pulses though.