I like a good smart watch and I appreciate open source, but an ESP32 isn't a great pick when low power consumption is important and the device is going to be communicating regularly. I'm surprised LILYGO went that direction in a watch form factor.
an esp32 on an 1100mah battery will last years on deep sleep, and about a day with wifi on and in high power modes.<p>a pixel watch 4 says they last 30 hours , ambiguously. they use a battery less than half the size. in reality with constant use they'll drop dead in 6 hours.<p>the thing is clunky and heavy , anyway -- so if it lasts as long as an off the shelf watch who cares?<p>also, the primary reason : lilygo shoves ESPs into everything.
What would you suggest instead?
Nordic Semi, or maybe ST Micro. I've got an STM32WB on my bench at the moment with sensitive coulomb counting and it looks very promising but without all those radios. Of course with all those radios (ie, if you need LoRa on a watch... which is a design decision I'm also skeptical of) then Nordic has a good track record.
Most of their lora devices are ESP32.
I would love to see some extra sensors for heartbeat, temperature, blood oxygen and whatever else could be captured by the design.
That's more a programmable watch than a DIY one :-)<p>I build mine from scratch, including the PCB and a 3D printed case.<p>For sure, that's not at all the same level of customability, programmability, capacity, nor quality. But It is really a DIY one.<p>For anyone interested: <a href="https://github.com/jblezoray/hpdl1414-watch" rel="nofollow">https://github.com/jblezoray/hpdl1414-watch</a>
Ok, we'll make the title say programmable instead.
I like your hpdl watch better than the LilyGo watch. As a lover of analog and casio watches I can tell you that your watch can soon build you a loyal following in its current form if you only build 3 such watches and put them on Amazon, etc. and price them at 50$. Next batch of 3 you could try at 100$.
Don't worry about glass cover, our local watch repair guy can easily slap one in it
It's cool that the firmware is hackable but I think "DIY" is an imprecise way to describe that.
No mention of battery life? I guess it depends on the software that you run. But it would be nice to have a benchmark for how long it would last in normal watch mode.
This is almost $80. The PineTime watch is less than half that price. Obviously the specs are different but that's quite a difference.
This device looks capable of a lot of features and possibilities. Unfortunately nothing comes to my mind because I'm not good with diy hardware (once connected raspberry pi zero with led strips). Could someone tell examples of interesting and/or useful projects one can implement with this watch?
There are only a few features I care about in a smartwatch:<p>1. O2 monitoring. I have sleep apnea and live at high altitude, so this matters to me.<p>2. Motion sensor. Also mostly for tracking sleep.<p>3. Vibrator for notifications.<p>4. A screen backlight.<p>5. Battery life longer than a week.<p>6. Waterproof enough to survive a splash in the shower/rain.<p>I consider GPS, cellular, AI, touchscreens, cloud-only sync and control apps, and just about everything else to be anti-features. There are no devices that really cover all this that I've found. A few Garmin and Amazfit/Zepp devices come close, but they have enough drawbacks for me to not be happy with them. The new Pebble is nearly perfect, but the lack of an O2 sensor is a dealbreaker for me :(
The Sensor Watch circuit board [1] inside the case of a Casio F91-W / A158W / A159W satisfies 2, 4, 5, and 6. Accelerometer or thermometer available as daughterboard.
Battery life measured in months, if not years. Although the simple LED backlight and the segmented LCD leaves a bit to be desired, and there is no wireless connectivity for notifications. Open source firmware.<p>The Ollee watch circuit board [2] is similar, better backlight but closed-source firmware and configuration over BLE in a smartphone app. Still no notifications over BLE though.<p>I'd think combining 1 and 6 (O₂ monitoring and waterproofing) would be difficult.<p>[1]: <a href="https://www.sensorwatch.net/" rel="nofollow">https://www.sensorwatch.net/</a><p>[2]: <a href="https://www.olleewatch.com/" rel="nofollow">https://www.olleewatch.com/</a>
The Pro version has a better screen (still segmented but more), RGB LEDs and an infrared sensor.
my experience with a sensor watch has been terrible.<p>imagine breaking a $3 watch that is not quite as indestructible as people think it is, but it is nonetheless pretty robust, and then trying to shove something 100x glitchier and 5x as expensive into its case...
I would buy it if it had wifi. A (decent to wear) watch with wifi would be awesome. Tons of ideas for apps I would build for myself<p>Ofc, im excluding apple
Does anyone know if this has an accelerometer? I recently got a nice sports-oriented smartwatch (non-Garmin), to use it mostly for rowing, but it doesn't track the rowing-rate. It should be pretty easy to program one if the watch has accelerometers, but couldn't tell from the spec sheet (maybe that means no?)
LILYGO site shows pre-orders of all 3 versions are sold out unfortunately.
There's an older "Plus" model available on Amazon.[1] Surprisingly cheap, at US$66. This new model is the "Ultra".<p>It's amazing that the market is big enough to get the price that low.<p>[1] <a href="https://www.amazon.com/LILYGO-T-Watch-S3-Development-SX1280-2-4G/dp/B0F48KVPB6" rel="nofollow">https://www.amazon.com/LILYGO-T-Watch-S3-Development-SX1280-...</a>
I doubt if esp32s3's power consumption can be used in real life.
Anyone know what the battery life is likely to be like?
s/Watch/Smartwatch<p>Regular DYI watches aren't big news...<p>(I would be over the moon for a DIY smartwatch with zero AI and e-ink screen.)
This does look very cool. Every peripheral one could think of, even LoRA!
Preorders sold out already!
No heart rate sensor
trun on and trun off
have wished for decades now there was an open-source Garmin on the level of Cyanogenmod / LineageOS for Android<p>not sure if it will happen this decade but definitely next decade<p>proper running/cycling metrics are hard as demonstrated by how many well-funded competitors are somewhat close but not there 100% yet (Coros, Amazfit, etc)<p>someone once hacked and decompiled older Garmins but newer ones are encrypted/signed/locked-down
Have you looked at the specs for the upcoming PineTime Pro [1]?<p>[1] <a href="https://pine64.org/2026/03/28/pinetime_march_2026/" rel="nofollow">https://pine64.org/2026/03/28/pinetime_march_2026/</a>
I'm very excited about this. GPS was the final piece of the puzzle.<p>I love(d) my bangle.js. Such a true hacker device. Really fun to use WebUSB and push JavaScript files as apps.<p>But the GPS on that device was a mess, honestly. I know this is a complicated problem but having to synchronize to satellites and recalibrate all the time was beyond me.<p>I really wanted it to work because I built my own toy run tracker visualization tool.<p>I am curious about this new lilygo device because it sounds like it has an alternative location sensor: "A u-blox MIA-M10Q GNSS module provides accurate location tracking..."<p>I'll need to look that up. Anyone have a summary on what's the difference between that and regular GPS?
Oh nice, didn't realize they were doing a second one. Loved the original but I took mine rock climbing and cracked it :(
> newer ones are encrypted/signed/locked-down<p>I have a garmin watch and didn't know this.<p>That said, I just used it out of the box, and never (on purpose) hooked it to wifi, bluetooth, garmin connect, etc. Can't do that with an apple watch.
I have a garmin from the late 90s and am saddened by the lack of FOSS software to even sync a new map onto it
not sure if this will help you but there is a neat website that allows you to build free maps for older Garmin models that didn't have them at first like Fenix5<p><a href="https://garmin.bbbike.org/" rel="nofollow">https://garmin.bbbike.org/</a><p>1990s is going way back though, they didn't even have mass-storage mode then, it was their proprietary "garmin mode" for usb which only things like BaseCamp can talk to