A programmable watch you can actually wear
127 points
2 days ago
| 21 comments
| hackster.io
| HN
oritron
7 hours ago
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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.
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serf
2 hours ago
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an esp32 on an 1100mah battery will last years on deep sleep, and about a day with wifi on and in high power modes.

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.

the thing is clunky and heavy , anyway -- so if it lasts as long as an off the shelf watch who cares?

also, the primary reason : lilygo shoves ESPs into everything.

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explodes
14 minutes ago
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Several Garmin watches last for weeks (24 days full charge, actual 1-2 weeks with heavy gps and fitness tracking), and I struggle to understand why consumers accept anything less. It seems like consumers don't realize what's available.
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shadowpho
1 hour ago
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I’ll need to check my notes on power consumption. I’ve spent quite a bit of time trying out different modes and configurations… it’s not great. I would not expect years at all. You gotta be very careful about what has to stay on and off.

Furthermore, bugs. To this time there’s random crashes that happen with sleep which limits their use

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sho_hn
36 minutes ago
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I have some relevant experience. I built this a few years ago:

https://imgur.com/a/diy-automatic-e-ink-newspaper-using-rust...

After careful optimization, the v1 got about 6 months out of a 1100 mAh battery. Later improvements and bumping to a 3300 mAh battery got me to 14 months, before my kid yanked it off the wall, total'd the panel and I rebuilt it. The test continues.

That said--op isn't wrong. If power usage is the metric you optimize for, there's much better BOM than an esp32.

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jolmg
1 hour ago
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An advantage of ESP32-S3 could be that it seems possible to run Linux on it.
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smlacy
6 hours ago
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What would you suggest instead?
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oritron
6 hours ago
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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.
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jkestner
5 hours ago
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Different use case (environmental data recorder) but our current product uses an STM that turns on an ESP32 (not trusting that sleep mode) when it needs radio, to run on 2 AAs forever.
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rylando
5 hours ago
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Do you have any info you can share on this recorder? Sounds really interesting!
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jkestner
4 hours ago
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http://supermechanical.com/pickup Been in production hell thanks to tariffs (wrote a lot about it) but should ship by summer.
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hrimfaxi
6 hours ago
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Most of their lora devices are ESP32.
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jblezo
7 hours ago
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That's more a programmable watch than a DIY one :-)

I build mine from scratch, including the PCB and a 3D printed case.

For sure, that's not at all the same level of customability, programmability, capacity, nor quality. But It is really a DIY one.

For anyone interested: https://github.com/jblezoray/hpdl1414-watch

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sho_hn
29 minutes ago
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Love it, especially your choice of digit display. Very nice hack! I'd wear that.
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Guestmodinfo
6 hours ago
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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
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hrimfaxi
6 hours ago
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The HPDL-1414 appears to be discontinued though still available from some suppliers in varying MOQs and leads.
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dang
2 hours ago
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Ok, we'll make the title say programmable instead.
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Retr0id
7 hours ago
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It's cool that the firmware is hackable but I think "DIY" is an imprecise way to describe that.
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deferredgrant
1 hour ago
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The nice thing about a project like this is that it shows how much taste matters in engineering. 'Works' and 'you'd actually use it' are very different milestones.
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sho_hn
34 minutes ago
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This is mean-spirited and daft.

This is a product aimed at a very specific hobbyist segment of the smart tinkerer, who will probably get more joy out of it than most buyers get out of their Apple Watch. Is that a smaller market? Yes. That doesn't make it a bad product.

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Retr0id
23 minutes ago
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I think it's a relevant critique for something that goes on your wrist, especially when products like PineTime exist in the same market segment with aesthetics much closer to an apple watch (an aesthetic I'm not fond of either, but hey, it seems to be popular)
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pickleglitch
5 hours ago
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This is almost $80. The PineTime watch is less than half that price. Obviously the specs are different but that's quite a difference.
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npodbielski
4 hours ago
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Where you can buy pinetine for 40$?
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jjulius
3 hours ago
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briandw
6 hours ago
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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.
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MrDrMcCoy
6 hours ago
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There are only a few features I care about in a smartwatch:

1. O2 monitoring. I have sleep apnea and live at high altitude, so this matters to me.

2. Motion sensor. Also mostly for tracking sleep.

3. Vibrator for notifications.

4. A screen backlight.

5. Battery life longer than a week.

6. Waterproof enough to survive a splash in the shower/rain.

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 :(

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Findecanor
6 hours ago
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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.

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.

I'd think combining 1 and 6 (O₂ monitoring and waterproofing) would be difficult.

[1]: https://www.sensorwatch.net/

[2]: https://www.olleewatch.com/

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zimpenfish
26 minutes ago
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> I'd think combining 1 and 6 (O₂ monitoring and waterproofing) would be difficult.

By O2 monitoring, they mean "blood oxygen through skin via LEDs" - there's no impact on waterproofing from that (as the Apple Watch demonstrates.)

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curiousgal
5 hours ago
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The Pro version has a better screen (still segmented but more), RGB LEDs and an infrared sensor.
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doctorpangloss
5 hours ago
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my experience with a sensor watch has been terrible.

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...

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rbanffy
2 hours ago
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I would love to see some extra sensors for heartbeat, temperature, blood oxygen and whatever else could be captured by the design.
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gitowiec
7 hours ago
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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?
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amelius
2 hours ago
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When can we finally buy a smartwatch that can keep its (color) display ON during the entire day?
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taejavu
2 hours ago
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September 18, 2020. That's when Apple released their Watch Series 6, which has an always on color display, and enough battery to last all day.
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gnabgib
2 hours ago
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A Garmin memory-in-pixel eInk (MIP) watch? Lots of choices there, since about 2015. Modern versions (MIP not AMOLED, the category is getting confusing) last about 10 days on a charge.
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joe_mamba
2 hours ago
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Watches with color memory-in-pixel displays have existed since Pebble.
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jolmg
1 hour ago
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To add, the current Pebbles are estimated to last 30 days. 10-14 days for the round ones.
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HardwareLust
2 days ago
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LILYGO site shows pre-orders of all 3 versions are sold out unfortunately.
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Animats
5 hours ago
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There's an older "Plus" model available on Amazon.[1] Surprisingly cheap, at US$66. This new model is the "Ultra".

It's amazing that the market is big enough to get the price that low.

[1] https://www.amazon.com/LILYGO-T-Watch-S3-Development-SX1280-...

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inasio
6 hours ago
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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?)
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fjfaase
6 hours ago
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It had a Bosch motion sensor with AI abilities it says in the description.
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sdevonoes
4 hours ago
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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

Ofc, im excluding apple

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jdiff
27 minutes ago
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It's an ESP32, it has wifi.
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matt_trentini
2 hours ago
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Oddly, the article didn't mention it - but the watch does have wifi.
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jdiff
26 minutes ago
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The article mentions it as "Wi-Fi" if you were scanning with Ctrl+F.
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chaosprint
4 hours ago
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I doubt if esp32s3's power consumption can be used in real life.
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JaggedNZ
4 hours ago
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Anyone know what the battery life is likely to be like?
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padjo
3 hours ago
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Bad.
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gamerslexus
8 hours ago
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s/Watch/Smartwatch

Regular DYI watches aren't big news...

(I would be over the moon for a DIY smartwatch with zero AI and e-ink screen.)

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stackghost
7 hours ago
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I would consider a DIY mechanical/analog watch to be far bigger news/more impressive than a smartwatch.
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bloggie
7 hours ago
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To be honest there is not much to it, you buy the movement, put it in a case, and put the hands on it. you can get everything from aliexpress. it's easier and often cheaper to just buy a normal watch if you need one.
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Avicebron
7 hours ago
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It's impressive you start with a lathe and make the movement yourself!
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saltcured
6 hours ago
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Not nearly as impressive as designing and fabricating your own integrated circuits and display!
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NooneAtAll3
7 hours ago
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buying movement is like buying whole PCB

DIY analogy would probably be about acquiring individual gears

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gamerslexus
7 hours ago
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Is it different with a smartwatch? You buy the kit, it's not like you solder much as far as I understand.
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gamerslexus
7 hours ago
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I thought so too, but after quick research apparently there are kits. For various values of "DIY", I guess...
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stackghost
7 hours ago
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Sure but buying a movement kit is no different than buying a pcb. Writing code is not impressive any more.
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jwr
7 hours ago
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This does look very cool. Every peripheral one could think of, even LoRA!
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hrimfaxi
6 hours ago
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That stood out to me, too. Garmin should take a hint.
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ImPostingOnHN
7 hours ago
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Preorders sold out already!
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dariosalvi78
5 hours ago
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No heart rate sensor
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ck2
8 hours ago
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have wished for decades now there was an open-source Garmin on the level of Cyanogenmod / LineageOS for Android

not sure if it will happen this decade but definitely next decade

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)

someone once hacked and decompiled older Garmins but newer ones are encrypted/signed/locked-down

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m463
7 hours ago
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> newer ones are encrypted/signed/locked-down

I have a garmin watch and didn't know this.

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.

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jerlam
1 hour ago
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The underlying Garmin platform is so old that it predates iPhone/Android. I think you can plug in many Garmins via USB without any special software and simply copy activities and data off the watch.

They had a segment of customers who wouldn't have or be allowed to connect a phone - triathletes, long-distance hikers, military. But it's been slowly changing as users want more modern features and the company wants to increase sales.

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rjsw
7 hours ago
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Have you looked at the specs for the upcoming PineTime Pro [1]?

[1] https://pine64.org/2026/03/28/pinetime_march_2026/

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xrd
6 hours ago
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I'm very excited about this. GPS was the final piece of the puzzle.

I love(d) my bangle.js. Such a true hacker device. Really fun to use WebUSB and push JavaScript files as apps.

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.

I really wanted it to work because I built my own toy run tracker visualization tool.

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..."

I'll need to look that up. Anyone have a summary on what's the difference between that and regular GPS?

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branon
5 hours ago
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Oh nice, didn't realize they were doing a second one. Loved the original but I took mine rock climbing and cracked it :(
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mghackerlady
7 hours ago
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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
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ck2
7 hours ago
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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

https://garmin.bbbike.org/

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

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mghackerlady
5 hours ago
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oh bud, mine doesn't even mention USB in the manual. I got the thing for like a dollar at goodwill haha
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avipars
5 hours ago
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trun on and trun off
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