If you’re lucky enough to work from home, you’ll soon find that it presents its own set of challenges, mostly related to work/life balance. It can get so bad that you don’t know what day of the week it is. Really. Ask us how we know.
Rather than miss a meeting (or a day off), prolific hacker [Arnov Sharma] created this day of the week clock. It uses a customized LED driver board with seven sets of three LEDs, each driven by a MOSFET. Each MOSFET is controlled by a DFRobot Mini Beetle ESP32-C3. It runs on a 2200 mAh, 3.7 V lithium-ion battery.
While this is mostly PCBs, there are three printed parts that turn it into a displayable object. We really like the look of this clock — it has just the right amount of pizazz to it and reminds us of a and old movie marquee. Be sure to check out the great build instructions.
We love a good clock around here. In case you missed it, here is the latest from [Moritz v. Sivers] that uses a caustic lens to display the time.
Umm this is seven-state finite machine. Somehow I think the ESP32-D3 is an overkill, but if it is cheap and runs mostly in deep sleep, to be awaken and send once-a-day-command, then it is kewl.
Point being, seven-state binary machine can be built with 2n2222s flipping on one state at a time. All the ESP32 has to do is wake up and read the current state, and if it is the same as needed, go back to sleep, otherwise slip it one bit forward.
I think I have my weekend project set :-]
(on a separate thought, a humble 360 degree servo can be the seven-state machine; a tiny magnet on the servo arm would turn on one of the seven reed switches … or something like that … mebe gray code wheel with seven sectors, one transparent … :-) )
@Sammie Gee: your first suggestion of a simplification make sense and then suddenly there is the servo approach… controlling a servo only makes things complicated again. While just a simple synchronous AC motor and some large gear ratio is all you need to make it turn 1/7 of a circle a day and done (use it to drive a splitfap or a large arrow on a circular scale).
These projects aren’t about the goal, they are just an excuse to play with the overkill tech. and to try out new ideas. And it does look nice. Anyway, if you want to know the day of the week, just watch the phone, you don’t even need to unlock it in most cases and that thing even tells the time…
Jan, yepyep, I usually have at least two unrelated thoughts running concurrently :-]
Electronically speaking, some kind of seven-state flip-flop with transistors would be easily readable by a microcontroller, and can directly drive the leds (or mosfets that light up the leds). That was the original thought. A transistorized shift register reinvented, of course (which could be done with 74VHC164, but transistors would be more fun to play with).
Electro-mechanically speaking, the simplest solution would be a ratchet rotating some kind of a plastic wheel with seven states that can be read by some kind of input device; reed switches seem to be the reasonably cheap and reliable tech, so a wheel with seven magnets, and no servo is needed.
Basically, I just reinvented the humble electric flip clock of the 20th century :-]
I was never found of the cell phones replacing simple and reliable tech (clock and calendar), but that’s just a retrograde me thinking “there is no reason to drive an eighteen wheeler where a small Beetle would suffice”.
Back to the thread at hand, I admire the design, which alone wins the contest of fitting the maximum amount of information within the minimum space available. Coupled with simple reliable tech makes it one awesome solution I’d probably find worthy repeating and potentially forking.
Sorry about the run-on rumblings, discard if pointless/irrelevant, etc.
Also, an AC motor rotating a seven-state splitflap sounds interesting. Comes this weekend I may give it more than one hour of thinking.
speaking from experience, you can’t use a 555 for counting days because its speed isn’t stable enough, after 24 hours you definitely notice the error :)
Close enough.
Besides, you can always use the ESP32 to reset the 555 when it get too far out.
There are 7 day clock movements available, so a seven segment face could accomplish the same task.