https://blog.jgc.org/2025/07/pimping-my-casio-part-deux.html John Graham-Cumming's blog 2025-07-18 Pimping my Casio: Part Deux Close to three years ago I wrote about using Oddly Specific Objects' alternate "motherboard" to modify a classic Casio F-91W watch: Pimping my Casio with Oddly Specific Objects' alternate motherboard and firmware. That blog post goes into the detail of swapping out the guts of the Casio and building and uploading the firmware. Happily, Oddly Specific Objects is back with a "Pro" version of their alternative Casio internals which now features an accelerometer and an alternative LCD. The original Sensor Watch used the existing Casio LCD display but the custom LCD allows for more complicated text to be displayed on screen. It's not a dot-matrix display so there are lots of limitations but it's still a fun upgrade. Also, the Sensor Watch Pro, as it's called, requires no soldering (unlike the original version). Here's one I prepared earlier (that is a Casio F-91W with new internals): [sw-pro-1] You can see the new display in action there showing the day as FRI. As with the original Sensor Watch there's a browser-based emulator that uses emscripten to get the watch running on your computer. This is pretty important because flashing new firmware to the watch requires dismantling it. [sw-pro-2] Since there's no soldering the process of upgrading your Casio is simply take it apart and put back in the parts that came in the kit (along with a small piece of metal that's transferred from the original Casio watch to make the battery connection): [sw-pro3] Since I bought the optional accelerometer add on it's necessary to put in place a little piece of Kapton tape (you can see if covering the five pads on the image above) and the insert the accelerometer board itself: [sw-pro-4] The five vertical traces at the top are the micro USB interface used for flashing the firmware. [sw-pro-5] I modified the firmware to remove Imperial units and 12 hour clock (which I never want) and to choose my own selection of screens (I added the tally, accelerometer and light sensor screens). The complete sequence of commands needed to build the firmware was: brew install --cask gcc-arm-embedded git clone https://github.com/joeycastillo/second-movement cd second-movement git submodule update --init --recursive make BOARD=sensorwatch_pro DISPLAY=custom And then to upload to the watch you connect the micro USB, click the tiny switch on the back twice very rapidly and a volume called WATCHBOOT appears on your machine. You can copy the firmware over to the watch with make install. To run the emulator you build with emscripten: brew install emscripten emmake make BOARD=sensorwatch_pro DISPLAY=custom python3 -m http.server -d build-sim And then visit localhost:8000/firmware.html in your browser. at July 18, 2025 Email ThisBlogThis!Share to XShare to FacebookShare to Pinterest Labels: clocks, hardware No comments: Post a Comment Older Post Home Subscribe to: Post Comments (Atom) Search This Blog [ ] [Search] Labels * anti-spam * babbage * behind the screens * calculators * codes and ciphers * gnu make * hardware * machine learning * mathematics * minitel * popfile * privacy * pseudo-randomness * radio * retro * security * the geek atlas * well... actually Popular Posts * [sw-pro-1] Pimping my Casio: Part Deux Close to three years ago I wrote about using Oddly Specific Objects' alternate "motherboard" to modify a classic Casio F-91W w... * [lbs] Low-background Steel: content without AI contamination Somehow I forgot to blog my site: https://lowbackgroundsteel.ai/ . I created it back in March 2023 as a clearinghouse for online resources t... * [casio-1] The discreet charm of the infrastructureless Early in the morning in a European city, I awoke and wondered for a moment where I was. The room was totally black apart from a small glow f... * [punch-1] Rabbit hole: stumbling across two Portuguese punched cards Look, here's the thing, I don't like mysteries that involve technology. I think I hate them because I know that some other human cre... * [casio1] Pimping my Casio with Oddly Specific Objects' alternate motherboard and firmware Some time ago I bought a replacement motherboard for my classic Casio F-91W from Crowd Supply. The project keeps the original Casio LCD but... * [Picture] Your last name contains invalid characters My last name is "Graham-Cumming". But here's a typical form response when I enter it: Does the web site have any idea how rud... * [AEn0k_uUwW] Controlling the Taylor Swift Eras Tour wristbands with Flipper Zero Many large concerts feature wristbands that light up on command. They are used to produce varied visual effects across a stadium. One compan... * [171421935] Cracking an old ZIP file to help open source the ANC's "Operation Vula" secret crypto code It's not often that you find yourself staring at code that few people have ever seen, code that was an important part in bringing down t... * [dim-bulb-5] It was time for a dim bulb current limiter One of my Minitels (the one that I modified a few years ago to run new firmware ) started having power supply problems: the LED was on but n... * [calcs-2] Just one more calculator, bro, just one more, I swear it's the last one I'm not much of a collector of things. Long ago I decided that on the retro-computing front I would not collect any machines that weren... Blog Archive * V 2025 (11) + V July (1) o Pimping my Casio: Part Deux + > June (3) + > April (2) + > March (1) + > February (4) * > 2024 (19) + > December (3) + > November (1) + > October (1) + > September (3) + > June (3) + > May (1) + > April (1) + > March (3) + > February (2) + > January (1) * > 2023 (30) + > December (2) + > November (5) + > October (3) + > September (4) + > August (1) + > July (5) + > June (1) + > May (3) + > April (3) + > March (3) * > 2022 (24) + > December (2) + > November (3) + > October (8) + > September (1) + > July (2) + > June (2) + > April (2) + > March (4) * > 2021 (6) + > November (1) + > July (1) + > May (2) + > April (1) + > January (1) * > 2020 (2) + > June (2) * > 2018 (2) + > December (2) * > 2017 (4) + > May (1) + > April (3) * > 2016 (11) + > November (1) + > September (1) + > July (2) + > June (1) + > May (3) + > April (1) + > March (2) * > 2015 (11) + > November (1) + > July (2) + > May (1) + > April (5) + > March (1) + > January (1) * > 2014 (4) + > November (2) + > July (1) + > June (1) * > 2013 (39) + > September (4) + > August (1) + > July (4) + > June (2) + > May (5) + > April (12) + > March (3) + > February (2) + > January (6) * > 2012 (77) + > December (3) + > November (6) + > October (6) + > September (7) + > August (6) + > July (6) + > June (8) + > May (4) + > April (9) + > March (7) + > February (9) + > January (6) * > 2011 (79) + > December (5) + > November (7) + > October (2) + > September (5) + > August (2) + > July (8) + > June (10) + > May (6) + > April (9) + > March (6) + > February (12) + > January (7) * > 2010 (95) + > December (13) + > November (9) + > October (16) + > September (19) + > August (2) + > July (9) + > June (12) + > May (1) + > April (1) + > March (4) + > February (2) + > January (7) * > 2009 (31) + > December (1) + > November (8) + > October (3) + > September (6) + > August (9) + > June (1) + > May (1) + > January (2) * > 2008 (19) + > December (2) + > September (1) + > June (3) + > May (3) + > March (2) + > February (6) + > January (2) * > 2007 (34) + > December (2) + > November (3) + > October (5) + > August (2) + > July (2) + > June (4) + > May (3) + > April (1) + > March (6) + > February (4) + > January (2) * > 2006 (25) + > December (2) + > November (2) + > October (3) + > September (5) + > July (1) + > June (1) + > April (6) + > February (1) + > January (4) * > 2005 (3) + > December (1) + > November (2) Copyright (c) 1999-2025 John Graham-Cumming. Awesome Inc. theme. Powered by Blogger.