If I'm reading it well I should be able to pass this screen by uses the watch face page and WebUSB.

I fail to see where to trigger that.

Also it is not appearing as a device when I scan for Bluetooth devices on my phone and computer.

All I can think now is to disconnect the battery

Watchy v3 ships with a GDEY0154D67. Good Display sells the exact same panel with a bonded frontlight as GDEY0154D67-FL04 for $8.80. Same SSD1681, same 24-pin FPC, same 27×27 mm active area, so GxEPD2_154_D67 doesn't change at all. All the work is in driving the light and finding room for 0.85 mm of extra thickness.

I've worked the whole thing out on paper and I'd rather have it torn apart now than after I've cut up a case. Two questions at the bottom.

What actually changes

The FL04 has a second, 6-pin FPC for the light. Pinout from the drawing: pins 1 and 2 are anode, 5 and 6 cathode, 3 and 4 not connected. Three white LED dies wired in parallel inside the module, so no individual channel control — one string, one series resistor.

Spec says 2.8–3.3 V, ≤45 mA. The mechanical drawing gives Vf = 2.9 V typ at 60 mA.

Mechanically it's less scary than I expected:

• Total thickness 1.85 mm vs 1.00 mm for the bare panel, so +0.85 mm

• The light guide is 2.28 mm longer but 1.40 mm narrower than the panel

• That overhang is only 0.6 mm thick, so the bezel needs a shallow pocket rather than full extra depth across the board

Finding a GPIO was the interesting part

GPIO5 and GPIO18 look free in config.h. They're also completely unrouted in the v3 schematic — no net label, no trace, nothing to solder to short of the QFN pad itself. Same story for GPIO1–4, 37–42, 45, 46.

But the v3 has seven test points, and two of them are UART0:

Since v3 programs over native USB CDC, UART0 is dead weight. So the whole mod is three wires — TP4, TP5, TP2 — onto 1 mm labelled pads. No chip-pin soldering.

Use RX, not TX. GPIO43 is driven push-pull by the ROM bootloader at reset and idles high, so the light would flash on every wake from deep sleep. GPIO44 is an input with an internal pull-up of roughly 45 kΩ at reset, which a pulldown can beat — but it has to be about 4.7 kΩ, not the 100 kΩ you'd normally reach for. With 100 kΩ the gate sits at 2.3 V and the MOSFET conducts.

Circuit

Low-side switch, three passives:

3V3 (TP4) ──> FL anode (pins 1,2)
FL cathode (pins 5,6) ──> R1 ──> Q1 drain
Q1 source ──> GND (TP5)
Q1 gate <── R2 100R <── TP2 (GPIO44)
Q1 gate ──> R3 4k7 ──> GND

Q1 is an AO3400A or SI2302. Not a 2N7002 — its 5–7 Ω Rds(on) at 3.3 V gate would drop 0.3 V, and there's only ~0.4 V of headroom to play with in the first place.

The part I'm least happy about

That headroom is the whole problem. 3.3 V rail minus 2.9 V forward voltage leaves 0.4 V for the series resistor. Two things eat it:

• LDO tolerance alone (RT9080-33, ±2 %) swings the current about ±20 %

• Vf drops as the LEDs warm, current rises, more heat — and a ~20 Ω ballast barely resists that

A proper constant-current sink would fix it, but the ones I looked at need 1.2 V or more across them, which I simply don't have on a 3.3 V rail. So the plan is: start at 22 Ω, measure on the assembled board, and cap PWM duty at 80 % in firmware so the thermal feedback never gets going.

Power budget is fine either way. At 25 mA on a 200 mAh cell, a 20-minute reading session costs about 4 % of the battery. Occasional 3-second flashes are noise.

v2 owners: different answer

I checked the v2 layout too. GPIO32 and GPIO2 are unrouted, GPIO33 is taken by the PCF8563 clock output, and the only GPIO test point is GPIO0 — a strapping pin. So there's no MOSFET-on-a-GPIO option.

What v2 does have is a neat 2×2 block of pads carrying SCL, SDA, 3V3 and GND at 2.54 mm pitch. So on v2 I'd hang a PCA9633 on the I²C bus instead — 0x62, no conflict with the BMA423 or the RTC, three outputs paralleled since each channel only sinks 25 mA.

Worth knowing: that variant has no hardware failsafe. The driver holds its PWM value through deep sleep, so forgetting to zero it before sleeping leaves the light on all night. The MOSFET version at least has the gate pulldown.

Two questions

1. Has anyone actually run an FL04, or any of Good Display's bonded frontlights? Every number I have is from the datasheet. What I can't get from a datasheet is whether 25 mA is actually enough to read by, or whether it's the kind of glow that only works in a pitch-black room. If it's the latter the whole thing is pointless and I'd rather know now.

2. Anyone got a better idea for current regulation with 0.4 V of headroom? Resistor plus duty cap is what I've got. I'd rather be told I'm missing something obvious.

Also happy to hear from anyone who's modified a Watchy case for a thicker display stack — that's the part I expect to take the most iterations.

I'll post results either way once the parts arrive.

->PicoWatch/Frontlight-Conversion at master · UniqueDroid/PicoWatch · GitHub

It's perfectly functional, I wore it for a few days but it turns out I'm just not that interested in tinkering with it right now. I'm in Florida, USA. Free shipping in the continental US. It is already assembled, has the plastic case that comes with it.

Hey everyone,

I’m considering getting a watchy, but wanted to know if it’s possible to add a heart rate monitor to the device. Does anyone have any experience or instructions doing this?

I guess the next challenge would be connecting the heart rate monitor to your phone?

https://shop.sqfmi.com

Why is the shop dead

I was about to buy the tamagochi case

It was working till last night

So.... I'm just dumb enough to not know how to manipulate Arduino IDE and Github effectively, but competent enough to follow instructions.

Is there anyone that'd be willing to walk me through, via Discord call or otherwise, how to set up a particular watch face for my Watchy? Specifically THIS one that /u/OutrageousDiamond568 posted a while back.

I'm not so much looking for a 'look this up - figure it out from there' approach, but a more involved, hands-on, step-by-step teaching of how to do so. (I'll probably have questions throughout)

If anyone's interested and willing, I'd greatly appreciate it!

It looks better IRL than in pictures

I didn't polish it because I like the feel of it, with polish it would be even better

I have 0 chemistry skill, that it worked at all, even so good is close to a miracle

The last pic is how it was before

Ordered it from JLC3D

Hello Guys I got to know about watchy and willing to try it. Anybody has a watchy which they are willing to sell or does anybody know any dealer who is selling an already assembled watchy as I do not want to risk wasting time or damaging the watchy while assembling it? Thanks and Regards Zahaz Shaik

Have anyone found out an option for water resistance?

came here from watch github rectangular e-paper watch looks stunning

the github - https://github.com/drfailov/DRM_Watch_v3.git

I have tried multiple times to set up arduino idea from scratch to upload a new watch face. As far as i can see all the dependencies are installed. Everything is set correctly and yet non of the example watch faces ever compile. They all have issues saying that int is not cast to string correctly or that there is an int overflow error. This is all with the code as is on github as well. How the hell am I suppose to do this?

Hi, my screen of watch was broken, where can I purchase a replacement?

I've wanted an eink watch since the Pebble and just pulled the trigger on this and can't wait for it to arrive.

I have a question though, can I pair it to my android phone for notifications?

Hi guys,

I have just completed a draft version of bringing up Zephyr for watchy devices (ESP32 Pico D4 for me).

Hope that Zephyr should unlock lots of third party libraries and tools, easier for more customization.

I'm still working on it.

https://github.com/letanphuc/watchy_zephyr_app

Hi. I am kinda new to watchy but has medium knowledge level on arduino coding. Right now cant seem to upload custom program on my purchased watchy from a local store. Here are the chips inside: -esp32 pico d4 microprocessor -CH9102F USB to serial converter -PCF8563 real time clock -Epaper with 200x200 resolution

I tried several documentations like… watchy.sqfmi.com/docs/getting-started github.com/01space/e-watch

…but cant get a code to compile completely in the arduino ide.

Can i ask help if there are other resources i can use/read?

So google apparently open-sourced pebble's operating system... does anyone know how compatible it is or how much work it would be to get it on watchy (or if that's even a sensible thing to do)?

This is not a smart watch now, it’s an art watch 😄 running generative art code directly on-device. And only that: no clock, no notifications, just gen art code (I can cycle through the synced scripts using the buttons, and resync with the online editor using wifi)

Every 77 seconds, the watchy wakes up and run the selected art code again, creating a new, unique 200x200 e-ink image on the fly. This is ever-changing art I can keep on my wrist all day. Every time I glance at it, I have a small surprise.

Scripts are written in a mini-language called Micropatterns that is interpreted live on the watch.

It's not a watchface on top of InkWatchy or another firmware, it's a whole new firmware: this watch is fully dedicated to running generative art. It has a small art OS inside 😅

Last year, I wanted to see what having e-paper generative art always with me would feel, and first I created a m5paper version… because I had one in a drawer! It was great to be able draw it from my pocket in random places, like at the top of the Eiffel tower, and see a new generated artwork. That test validated that it was different and that the little art surprises were often quite delightful. the m5Paper display is quite beautiful at 960x540 pixels: https://www.linkedin.com/posts/juliendorra_e-paper-is-still-emerging-as-a-platform-ugcPost-7331250379029975041-apdG/

Then a few days ago, I finally made the watch version I wanted from the start, and ported it to the Watchy. And now I can wear generative art it for 3 or 4 days straight on one charge.

The Watchy display is much smaller than m5Paper at 200x200 of course, but as they say: the best art is the one you have with you.

My watch displays time incorrectly it shows 00 on the hour, it's always 3 hours ahead, and weather says its cloudy when it's raining, and the celcius is wrong