Creating a pick and place control board with the RP2040 • Hacker News Board

Re: Creating a pick and place control board with the RP2040

#21

Post by AceJohnny2 » Sun, Nov 06, 2022, 5:55 AM UTC

> Starting from the left, the power comes in through screw terminals (J201, J202). The extra screw terminal is for daisy-chaining power to other boards.

Sopa-box time! Screw terminals suck. They're just... the default.

Great Scott had a good overview of some alternatives: https://www.youtube.com/watch?v=KE3CjZ0BUFo

Re: Creating a pick and place control board with the RP2040

#22

Post by a9h74j » Sun, Nov 06, 2022, 6:59 AM UTC

adamrmcd wrote: post #2

I am absolutely loving the author's explanation on WHY each component was selected, placed, and caveats. The interactive schematics and gerbers are subtle but very effective. Overall a very clear design and tone I really need to follow for my own PCB projects.

FWIW, when I was thinking more about text-based literate circuit design, one of the advantages I thought of was to leave ample place to comment upon selection rationale for (and subsequent experience with) particular components.

Re: Creating a pick and place control board with the RP2040

#23

Post by fuckstick » Sun, Nov 06, 2022, 7:19 AM UTC

AceJohnny2 wrote: post #21

> Starting from the left, the power comes in through screw terminals (J201, J202). The extra screw terminal is for daisy-chaining power to other boards. Sopa-box time! Screw terminals suck. They're just... the default. Great Scott had a good overview of some alternatives: https://www.youtube.com/watch?v=KE3CjZ0BUFo

Funny because none of those are really alternatives though - the screw terminals are a PCB mounted device and the comparisons were all wire to wire.

And in the final analysis of that video they measured out to 22 mohm so they note they’re fine for low current work.

Screw terminals don’t suck - they have their applications and they’re economical.

Re: Creating a pick and place control board with the RP2040

#24

Post by shadowpho » Mon, Nov 07, 2022, 11:32 PM UTC

theacodes wrote: post #3

adamrmcd wrote: post #2

I am absolutely loving the author's explanation on WHY each component was selected, placed, and caveats. The interactive schematics and gerbers are subtle but very effective. Overall a very clear design and tone I really need to follow for my own PCB projects.

Author here, thank you for the kind words! My goal is always to write the thing I would've wanted to have when I started out.

Beautiful write up! I love seeing those flyback diodes and ESD, many DIY and even products avoid them and product suffers.

One thing I wanted to add - I recommend placing a large-ish cap (22u) when using ferrite bead\inductor, as you can get ringing/oscillation otherwise.