Tweets
The character set, I think! Because of the F-91W’s quirky LCD layout, there are some limitations: the 1st and 3rd digit require a “lowercase” 7, and can’t display most letters. Top left can do almost everything; its neighbor, less so. Top right pair can show numbers from 0 to 39.
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Replying to @josecastillo
update: power on at my folks’ house; they’re warming up. Side note, if anyone in your feed tries to blame green energy for the blackouts, send them this. TL;DR: it was mostly natural gas, offline due to cold weather, ineffective regulations and capitalism. https://www.greentechmedia.com/articles/read/texas-energy-system-faces-a-winter-reckoning
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My grandma’s lifeline phoned my parents because it detected a temperature of 40° F (4.5° C) inside her house. She’d been without power all night. They braved icy streets to get her, but now she’s headed back to their house, where power is on for 2 of every 20 minutes. WTF, Texas?
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Replying to @tablatronix
I think it’s possible that on the prototype board, there was higher stray capacitance from the longer traces to where the capacitors had been, and maybe that was enough to get it ticking. Either way, I need to put them back if I want the device to work reliably.
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Replying to @tablatronix
the data sheet suggested I could use a 32k crystal with low load capacitance and omit external capacitors. to be fair I pulled the caps off of one prototype to try it, and it seemed to work… then I omitted them from the design only to find that now the crystal doesn’t oscillate.
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Replying to @josecastillo
We’ll get there.
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Replying to @josecastillo
on the upside (downside?), I’m doing such a terrible job at porting the software libraries I need, odds are I’ll need the extra time just to find my way out of the firmware morass in which I’m currently tangled.
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i’m without question upset about the fail I brought upon myself with this rev. But there are wins in here too. The pinout is set, and I can now address all segments of the F-91W LCD. Will have to burn another $30 and 2 weeks waiting for boards with the tweak, but hey, so it goes.
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on a more joyful note, my sister and I wandered out to Jamaica Bay Wildlife Refuge yesterday. Eleven years now in NYC, and somehow I had never made it out there before. Magical spot.
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current mood
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Replying to @yacky_yam and @kaeptnkrunch
Still waiting on that one last part, a navigation joystick, before I can get a first run of boards made. Unfortunately the order just barely didn’t make it out of China before the lunar new year, so it’ll be a bit more of a wait 😕
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Replying to @josecastillo
but i also recognize that for the better part of a decade i’ve been guarded and armored, refusing to let anyone too close. because the truth is, i like living life on my own terms. idk. i may try one day to do better. it isn’t much. but it’s the valentine’s day wish i can manage.
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Replying to @josecastillo
but looking back, i did everything on my own terms, to the point that i didn’t leave room for anyone else. surely part of my issue is years living through homophobia and fear; that kind of upfuckedness doesn’t leave your brain the moment society decides it should get better. (2/)
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a few years back i wrote a mission statement for my life: “save enough money to do great work on my own terms, and trust that the right guy will catch up.” in hindsight it was not a very good mission statement. oh, it started off fine: i built my moat, and the work is sound. (1/)
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This vote makes clear the dire importance of ensuring a Republican never holds the presidency again. I don’t care if Democrats aren’t to your liking. The next R to win the presidency will treat it as license to end our democracy. #voteforthedemocrat like your life depends on it.
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Replying to @jasoncoon_, @autodesk, @ADSKEAGLE, @adskFusion360, @kicad_pcb and @FreeCADNews
I also the hate the idea that I’m locking anyone who wants to fork my designs into this pricing structure. It’s probably the biggest factor pushing me toward KiCad. (tho KiCad looks like a great tool, and I sense I’ll really enjoy using it once I’ve spent some more time with it)
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Replying to @AdhesiveCup
I’m impressed at how many tapes have stuck around!
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Replying to @mattk
Thanks! I’m going to be honest, I’ve used it in some past projects and I’m about 50/50 on actually getting it soldered down and working. But I’m better at this now than past-Joey was, so fingers crossed!
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Replying to @tahnok
This is why I’m so stoked on the possibilities of the 9 pin connector and the tiny ’extra’ area… that idea totally didn’t occur to to me, but it might be doable, and I’m curious what other possibilities people might come up with!
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Replying to @tahnok
Oh totally, a compass would be a great addition! And one could reuse the weekday display slot for cardinal directions: there’s exactly one slot on the watch display that can show a W.
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came up with three extension boards for the Sensor Watch tonight. Well, two; one just adds a Flash chip, tho I expect it won’t work all that well. The space available for extra parts in the watch case is minuscule: <6x6mm, and no part over 1mm tall. Still, room for possibilities!
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Replying to @lisica27538942
Big brains, little power, I hope!
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more paper craft fit tests. Because it wasn’t ambitious enough to stuff one custom PCB into a 34mm watch case. I’m going to try for two.
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Replying to @tannewt, @oshpark and @timonsku
I’ve been using this part with success so far. This is with copper only on one side and soldermask only on the other. Measured thickness of that part of my flex PCB is 0.17mm, which is within tolerance; I might add silkscreen underneath for the last .03mm. https://www.digikey.com/en/products/detail/hirose-electric-co-ltd/FH19C-9S-0.5SH(10)/9360237
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Replying to @josecastillo
side note: I think it’s funny that I can earnestly say that my work now involves a quest to find the right crystal. am a new age healer / psychic? part of the marketing team for goop? video game hedgehog? all these things could be reasonable, given the prompt.
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tonight’s build went well overall. There’s one bit where I may have shot myself in the foot. but I’ll figure it out another night. (tried to use a crystal without external load caps. but the data sheet said I could do it, so maybe it’s just a matter of finding the right crystal?)
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Replying to @cynorg
But in terms of real resources that got me to the point I am now, this tutorial from @siddacious that brought a lot of the big picture stuff into focus; then it was a matter of looking at many boards and schematics until things started to make more sense. https://learn.adafruit.com/making-pcbs-with-oshpark-and-eagle?view=all
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Replying to @cynorg
It all started with my desire to build the Open Book, honestly! At first I was just poking at Eagle not knowing what I was doing, looking at Adafruit’s open source designs. But this was the first PCB I ever designed, based on the perma-proto FeatherWing: https://twitter.com/josecastillo/status/1124856274494140416
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Replying to @josecastillo
Coda: now that I feel confident this design is going to work, I’ll tag some of the folks who inspired it: @travisgoodspeed’s GoodWatch led @GregDavill to design arm-watch with a SAML22. Lukas K’s Pluto, a design based on the Casio F-91W, inspired the rest. https://github.com/carrotIndustries/pluto
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Replying to @josecastillo
While I couldn’t use OSH Park for the final boards — they needed to be 0.6mm to plug in to USB, and to fit in the watch case — these prototypes taught me a lot, and gave me a platform to hack on for the last three weeks. Now my boards are here from overseas and I’m ready to roll.
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Replying to @josecastillo
It feels to me that OSH Park has sped up that loop for hardware, from “this feels so difficult as to be unlearnable” to “upload your design Monday and we’ll fabricate it by Friday”, at a price point where you can just try some stuff and not freak out if the stuff doesn’t work.
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Replying to @josecastillo
Last month Limor Fried of @adafruit gave a great keynote at #lca2021. In it she mentioned how valuable it is to speed up the loop between writing & running code. Like, back when you had to wait 30 minutes to reprogram a microcontroller, iterating was hard. https://www.youtube.com/watch?v=jZnDCs80b_A
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Replying to @josecastillo
A few years back, long before I knew how to design a PCB, I remember just accepting that it was a skill I’d never have. It was expensive and slow to get boards made, and I didn’t know how I would ever learn. Then OSH Park made it cheap and quick — quick enough to learn by doing.
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Replying to @josecastillo
30 days ago this was a wild idea for a tiny gadget based on a chip I’d never worked with. For $10, I was able to get boards to play with inside a week and a half. Built them, found some mistakes, learned from them; designed a second rev; learned some more. https://twitter.com/josecastillo/status/1348474279952855044
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Second prototype, we hardly knew thee! Final prototype boards for the watch are in; I plan to assemble one tonight. These boards are not purple. But this thread is a love letter to @oshpark. The fact that I was able to bring this design into the world hinges on them. Some notes:
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Replying to @tannewt
Not yet, but this does seem like the way to go since eventually I’m going to want tinyusb working on this device regardless. Thanks for pointing me in this direction!
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Replying to @tannewt
I started w/ Adafruit’s fork of uf2-samdx1, but the SAML22 is surprisingly different from the D21/51 so there are a lot of ifdefs and it’s possible I’m missing a crucial step. Do you think it’d make sense to do tinyuf2 instead? The project structure does seem clearer for porting.
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Replying to @josecastillo
in hindsight it was ambitious to think I could do this in a weekend. It compiles, I guess, but it doesn’t work — probably because I don’t know anything about anything. I don’t even know what I need to learn to get it working. but not knowing is the first step to figuring it out.
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Replying to @_nitz
this was in the middle of my screen when I opened twitter, and I instinctively tapped “not now” twice before realizing it was a screenshot, so yeah, ya got me.
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coda: one month ago tonight. https://twitter.com/josecastillo/status/1347008547016601603
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One month ago today. Never forget that it happened here. Our democracy is more fragile than we thought, and this autocratic attempt damaged it further. Never forget that it could happen again. Stay vigilant, and oppose fascists in every election. Because next time, it could work. https://twitter.com/josecastillo/status/1346935172738985987
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One month ago today. https://twitter.com/yoda/status/1346911147774001154
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One month ago today. https://twitter.com/byaaroncdavis/status/1346908166030766080
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One month ago today. https://twitter.com/josecastillo/status/1346904023123824645
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Replying to @VE7FIM, @GregDavill and @arturo182
That’s a very good point, you’re probably right. I know the RPi folks are optimizing for something, but I’m almost certainly not clever enough to know exactly what it is.
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ok so my segment mapping needs some work, but at least second prototype can address all the digits I want to display! (side note: it’s gonna be watch stuff for a few days here)
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Replying to @theavalkyrie
I clicked the “like” button, but I meant it as an “I feel your pain” button 😖
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I believe this watch idea has potential. but there are a few things I need to do to get it there. Step 1: port the UF2 bootloader to the SAM L22 that runs the watch. Drag & drop firmware upload over USB will make it easy for folks to program it the way they want. Weekend project.
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Replying to @GregDavill and @arturo182
I’m wondering if those six extra GND pins on the Pico are meant to become GPIO while keeping the same footprint. 56 seems like an odd number of pins for a chip. 64, on the other hand…
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Replying to @arturo182
Well would you look at that! I’ll admit, I never think to search LCSC, but those both tick all the boxes. Thanks for pointing me in this direction!
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