[HN Gopher] Creating a pick and place control board with the RP2040
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Creating a pick and place control board with the RP2040
Author : scottwick
Score : 100 points
Date : 2022-11-05 16:46 UTC (6 hours ago)
(HTM) web link (blog.thea.codes)
(TXT) w3m dump (blog.thea.codes)
| adamrmcd wrote:
| 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.
| philsnow wrote:
| Usually when I read through a build-out description like this,
| the author writes it for an audience that has a lot more
| background knowledge than I do. This article, on the other
| hand, was lucid and the explication helped me follow along.
|
| I got to the part about 3.3V being derived from 5V and thought
| to myself "why not get it from 24V?" and then just a tiny bit
| later, there's the bit about USB and how Starfish can just take
| 5V from the USB host, and it clicked.
|
| I also learned about Sparkfun's QWIIC connector in the aside
| about the chosen i2c bus switch having two "extra" channels.
| Love it, thanks for the article, Thea.
| theacodes wrote:
| 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.
| jakewins wrote:
| Second the poster above, really enjoyed the reasoning around
| how and why you picked parts and the intent of various
| circuits..
|
| Do you have any books you recommend on electronics? I feel I
| understand the basics, like what various components do in
| isolation, but would love to level up and understand circuit
| design like how you are approaching it here
| theacodes wrote:
| I'll echo sibling's comment about just doing it. Theory
| only takes you so far, it's important to actually build and
| experiment, even if it's just in a simulator.
|
| I can recommend Practical Electronics for Inventors as a
| solid base of projects to experiment with and learn from.
| If you want to learn how to improve circuits and optimize
| for specific behaviors, there is a wealth of information in
| manufacturer application notes. A lot of the protection
| circuitry used in my article follows advice found in
| application notes.
| caraffle wrote:
| IMO the best way is to just pick a project and work on it.
| Using application notes and datasheets lets you piece
| together circuits, and you pick up design patterns along
| the way.
| scottwick wrote:
| Fantastic write up - thank you! I also love hearing about why
| each part was chosen. As an electronics hobbyist I often
| mimic portions of others' designs but I'm not always entirely
| sure why a certain part was chosen among the various options.
|
| Do you prototype all this on a breadboard before making the
| PCB and picking specific parts? I'd be curious to hear more
| about your process. I feel like I always need to test
| everything I build on a breadboard first since I inevitably
| miss some small detail if I go straight to schematic + PCB
| design.
| theacodes wrote:
| Great question! It really depends. If I'm working with a
| part I haven't ever worked with before, I'll often make a
| minimal breakout board that I can talk to with a devboard
| like an Arduino or Feather.
|
| If I'm pretty familiar with everything, I generally dive
| into a rough PCB layout and debug from there. If I
| absolutely can't get anything to work, I'll go back to the
| drawing board and possibly do some little breakouts, for
| example:
| https://twitter.com/theavalkyrie/status/1457845661370568709
|
| Edit: for this specific project I did make breakouts for
| testing the MOSFETs and solenoid drivers. I'm glad I did,
| since I was able to try out a couple of different options
| for each:
| https://twitter.com/theavalkyrie/status/1550878465876004865
| sintezcs wrote:
| I'd be happy to read about the software part of the project. How
| was the firmware created? Which language was used and why? How
| does it communicate with the host and what software do you need
| to run on the host?
| theacodes wrote:
| Hi! I'm planning on talking about that in an upcoming post.
| There's options - you can run 3d printer firmware like Marlin
| (C++/Arduino) or Klipper (Python & C), the tricky bit is
| getting those to talk to the vacuum sensors. Communication is
| via gcode commands sent over USB serial. Most folks are running
| their Lumen with OpenPNP on the host.
|
| I'm actually running completely custom firmware that I wrote
| specifically for this board that's written in C and uses
| Raspberry Pi's pico SDK. It's similar to Marlin/Klipper in that
| the host communicates via gcode over USB serial and that
| movement commands are more or less done the same, but it gives
| me the flexibility to simplify the whole host view of the
| pneumatics. It absolutely wasn't necessary for me to this, I
| just wanted to.
| KANahas wrote:
| @theacodes-
|
| I'm blown away by the awesome inline KiCad visualizations. Did
| you use any tooling for capturing the layout view so the layers
| could be overlapped so easily?
|
| Any thoughts on making a library for this so others can build
| sites as beautiful as yours? It'd be a great tool for sure. As
| noted elsewhere in the comments, your documentation is top notch.
|
| Thanks!
| theacodes wrote:
| Thank you! For the board layers I just used macOS's screenshot
| utility, though I would like to do something fancier in the
| future. The schematics are rendered using code I wrote
| specifically for this article, but I am planning to publish it
| as an open source library so others can use it. It needs a
| little bit more polishing before it's ready, though! You can
| follow me on Twitter if you wanna get updates about it.
| e-_pusher wrote:
| I wish there was an easy way to embed a KiCad layout to a
| webpage in a zoomable format for design reviews. One way is
| to export an SVG file and show it on the web, but in my
| experience this starts to choke on large boards.
|
| This website has a cool implementation of a KiCad web viewer:
|
| https://climbers.net/sbc/kicad-web-viewer/
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