Tweets
Replying to @mark_mcgookin
Yep, pretty much! Buck/boost ”switched mode power supply”; it’s super versatile, but requires an inductor it can switch on & off to do its job. If you’re only stepping down (like many Feathers) you can use an LDO instead, which can be less efficient, but doesn’t need an inductor.
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Replying to @xuyunzeng and @Raspberry_Pi
Great article btw — I’m bookmarking that!
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Replying to @xuyunzeng and @Raspberry_Pi
Interestingly it might only apply to the Pico! The Pico W uses a different buck/boost, the RT6154, which has higher max output (presumably for the wifi). Its data sheet suggests that it doesn’t have the same level of efficiency at low draw as the RT6150: https://www.richtek.com/assets/product_file/RT6154A=RT6154B/DS6154AB-03.pdf
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Replying to @ajbauer
If you’re having pond problems, I feel bad for you son. We got 10,000 lakes but a Kari ain’t one.
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Replying to @josecastillo
this is something I discovered when feeding different input voltages to the Open Book with a Nordic power profiler. I was surprised to find that at 3 volts I was drawing less power than I was at 3.7 volts. Dug up the data sheet, and I found my answer why. https://www.richtek.com/assets/product_file/RT6150A=RT6150B/DS6150AB-05.pdf
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Raspberry Pi Pico tip: if you’re powering your gadget with AA cells, you might be tempted to use three of them. If your current draw is high, that might make sense. But if it’s <10 mA — like the Open Book — the Pico’s RT6150 buck/boost is at its most efficient with just two AA’s!
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Replying to @yacky_yam
I’m working on the BOM today, it’s live in a branch of the repo but I want to merge it to main this week.
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Replying to @MakeItHackin
With NiMH batteries ≥2.8 V is fully charged, and it completely cut off around ~1.8 V. But I didn’t track the middle part. Based on the discharge curve, I sense that it’ll decline quickly to 2.6 V (80% charge), then slowly to 2.4 V (20% charge), then quickly again to 2 V (dead).
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Battery finally died after a month of reading + testing, so I’ve added a voltage label. This is why I needed a proper UI framework: I add a subview, hook it up to the power update event, and magically my UI framework tracks the updated region and refreshes it at a byte boundary.
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Replying to @josecastillo
ok clearly this is my design now. My head’s still in old school BBS-oriented retro stylings; this is almost all done with plain text and Unicode box drawing characters. (The Open Book’s font is stubbornly 8x16, a hard requirement that’s limiting, but necessary)
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Replying to @josecastillo
🤔
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Replying to @_initrd and @DLX
I might have to steal that cross hatch, it’s quite nice!
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Not my designs obviously — the iPhone UI is concept art called “iOS ‘86” by Anton Repponen — but I’m throwing some old school monochrome designs onto the Open Book’s screen, just as an exploration. (I don’t think these make a lot of sense fwiw)
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Replying to @ItsMrJP, @voctav, @helenleigh and @DHammarskjold
I’m sorry I forgot to give you one @voctav! @sethkazarians printed several, but I was still carrying one by the end; it must have been the one I meant to give you. Files are online though! STL here, I’m hoping to put the OpenSCAD source up soon as well. https://github.com/joeycastillo/The-Open-Book/tree/reboot/3D%20Printed%20Case
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A question about the Hiking Log (over on Mastodon — get yourself over there!) got me to dig up an old thread about it. In hindsight, 2019 was such a pivotal year for me. I feel like my whole philosophy of building things emerged through the making of this log-shaped data logger. https://twitter.com/josecastillo/status/1178833560851103744
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RT @Twitter: Twitter is about to go offline. See you soon!
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Replying to @_ekau
Turns out it’s well within your skillset!
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This makes me so happy! One more Open Book out in the wild. Congrats Erika!! https://twitter.com/_ekau/status/1592228023373529088
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Replying to @josecastillo
Thanks @prcutler for chatting with me, and for cutting my ramblings into something comprehensible 😃! Also make sure to listen to the end for my answer to Paul’s weekly question: “You’re about to start a new project. Which microcontroller do you reach for?”https://overcast.fm/+3B6DsPVeA
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Replying to @josecastillo
Finally, low power. If you’re even remotely interested in extending the battery life of your gadgets, give this section a listen. This clip talks Arduino, but we soon get to CircuitPython Deep Sleep + a ton of good practices for sipping power on a budget: https://overcast.fm/+3B6DsPVeA
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Replying to @josecastillo
Next: GUIs and the Open Book. Its UI framework, Focus, is a sort of event-driven framework with views and subviews and a responder chain, and I first implemented those ideas using CircuitPython! A framework I called “circuitpyui”. We delve into that story: https://overcast.fm/+3B6DsPVeA
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Replying to @josecastillo
First up: I²C. I’d shared that I built the I²C driver for the LCD FeatherWing in #CircuitPython first, then later ported it to Arduino. Paul asked why, and this is the kickoff to that answer. TL;DL: when something isn’t 💯, CircuitPython explains why. https://overcast.fm/+3B6DsPVeA
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It was so great to talk to @prcutler for the @circuitpyshow this week! We had three main areas of focus: I²C and the LCD Wing, GUIs and Open Book, and building for low power. Highlight thread, but first, here’s me on the origin of “Oddly Specific Objects”. https://overcast.fm/+3B6DsPVeA
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Replying to @crulge
The most fucked thing is, if it makes them money (or prevents a greater loss), wouldn’t the banks have a fiduciary duty to sell him the debt? Just like Twitter “had” to force the sale, because selling at that price created the most value for shareholders. It’s all just so absurd.
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Replying to @gennyble
Starting things is the hard part. After that you just need to do things, which is… also the hard part. Then you have to keep doing things. That’s hard too. and don’t get me started on finishing…
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Replying to @josecastillo
Who am I missing, I tagged the mastodon folks… @helenleigh @voctav @DHammarskjold @ItsMrJP, firmware update for Supercon Open Books! Better lock screen experience, plus support for plain text files without title metadata. UF2 to upload to the Pi Pico: https://www.oddlyspecificobjects.com/projects/openbook/book.uf2
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Replying to @josecastillo
OH ALSO! If you built one of these at Supercon, there’s a new firmware that you should use instead of the one I flashed: https://www.oddlyspecificobjects.com/projects/openbook/book.uf2 fixes some lock screen UI, and adds support for plainer plain text files. 🐘davedarko@chaos.social… https://mastodon.social/@joeycastillo/109338451288846086
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this has been an ABSOLUTE MONSTER of a weekend writing documentation for the new Open Book, but my god it feels good to have something out there. Complete with some hand-made “screenshots” of the UI, since I don’t have code to do a screenshot on-device 😬 https://www.oddlyspecificobjects.com/projects/openbook/
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Replying to @MakeItHackin
For e-paper screens I’d write “It’s now safe to press the power button.”
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Replying to @craigsburden
Power saving, yes. Ideally I’d like the lock button to go into low power mode and wake back up from it, but the RP2040’s dormant mode doesn’t go as low as I’d like. So for this version I’m directing you to pull the Enable pin low via the switch, to kill all power to the board.
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Replying to @Aask42
Your PCB has this tweak already! This change was a couple of revs ago; the only thing I’m changing for the next round is some silkscreen text, and a very slight adjustment to the buttons for easier hand soldering. They’re currently fine, but could be made even friendlier :)
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Replying to @josecastillo
The joy of this UX: you’re reading, you’re pausing, you press the button. Power is on; this message directs you to turn it off. But it’s e-paper, so the message stays on screen! Later, you pick it up. “Slide the power switch to continue.” Same text, but now it turns the power on.
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Working on Open Book firmware tweaks for folks who built one. UX note: I literally respun the board to enable this interaction. When you press the Lock button, I wanted message directing you to turn the power off. Obviously I had to move the power switch to align with the banner!
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Replying to @ajbauer
I’m fond of saying that a Republican has won the popular vote for presidency twice in my lifetime: 1988 and 2004 (and even then only with the benefit of incumbency). In terms of “getting elected” with a popular majority, George H. W. was the only one to do it.
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Highly suggest reading this whole thread. “Over the next few days, we have a chance to make this the worst website to ever exist. We have a chance to act like a pack of rowdy orphans with nothing to lose but our twitter handles and our lives.” https://twitter.com/handsomeadult/status/1591088861266202625
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*in an all hands call on the mars colony*
“the truth is yes, starvation is a possibility, and I don’t know how you’re going to make more food. But if you want to get stuff done, you know: maniacal sense of urgency. Just go ‘aah!’ Hardcore!”
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Replying to @JeremySCook
Me either, but this sounds accurate tbh: “A widely detested derangement engine ruled by a sociopathic algorithm, reviled and abandoned and in every sense but the most literal a haunted space station where lonely retirees turn into blood-and-soil fascists.” https://defector.com/facebook-meta-asks-wouldnt-it-be-nice-to-die/
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Replying to @josecastillo
It would be sad for something so significant to die in a slow decay like MySpace or Facebook, shambling along zombielike through various schemes. Much better for it to go supernova, a blinding flash of a cautionary tale, a beacon for those to come: “Don’t let this happen to you.”
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I joined Twitter before it knew what it was, but my fondest memories were when it was the ambient intimacy system: a place where you could tweet “I’m at Little City” and a friend would show up to say hello. I hated what it became, and if it has to die, I’m glad it dies like this.
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Low power gadget watch! 41 days in, and I’m only now getting a low power indicator on the Newt. I didn’t put a battery icon in my Inkplate’s UI, but it’s still dutifully updating the satellite view. @crowd_supply https://twitter.com/josecastillo/status/1582962218626613249
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Replying to @ajbauer
We’re all so focused on verified account hilarity that we’re neglecting real advances in the reply-guy state of the art since reply-guy in chief has taken over.
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with thanks to @GregDavill for suggesting free-angle routing. https://twitter.com/josecastillo/status/1583660714597974016
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Reused packing material tells a story of how things get made. Paper padding from DigiKey in Minnesota, in a JLC box sent from Shenzhen to Augusta that I received in San Antonio full of Sensor Watch boards. Now headed back to Georgia full of LCD Wing panels. 😎
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Replying to @tdsepsilon
Seeing a lot of folks on http://leds.social and http://chaos.social, but it doesn’t really matter. Personally I’m on the original http://mastodon.social and I still see everyone’s posts; with limited exceptions, all the servers connect to each other.
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What I imagine Twitter company laptops look like right now. (CW: flashing lights, motion, mention of self harm) https://twitter.com/rgb_0/status/1585361251638874112
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Replying to @AlpenglowInd and @virgilvox
NET SEND represent!
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interesting data point: this was cross-posted from Mastodon, and it’s gotten more comments and discussion over there than it has here. Maybe partly Twitter algo deranking, but still. There’s no denying that we have a critical mass of #ElectronicsTwitter folks over there. https://twitter.com/josecastillo/status/1590805535695126529
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Replying to @kfury
It too isn’t boring. https://www.statesman.com/story/business/technology/2022/11/08/elon-musk-tunnel-austin-tx-plans-canceled/69616709007/
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🤔 https://twitter.com/TesIaReal/status/1590820573932052480
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Am I missing something, or is this “recommended solder footprint” kind of useless?
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