Lift your spirits everyday on Imgur:

Sam March

AttachmentsFri, May 17, 4:32 PM (19 hours ago)

to me
Hi Mik,

Thanks for the kind words! I love seeing other peoples work, so this is very very cool. I will try my best to answer questions and if I miss something, just let me know!
For the microcontroller, I ended up picking the dialog part for 2 reasons, one it is super low power! It only uses ~3mA during transmit. The other reason is it has a power management system baked right into the package, all you need is an external inductor and you have a buck-converter, various LDOs, and a LiPo charger all baked in. It was the first time using the part, but I had been wanting to try out a dialog part for a while. The whole project took me about 3ish months of work, but that was most during nights after work or weekends when I had time (roughly 60ish hours of work total).
I’m intrigued by the watch bands you ended up using. Are they for something like a fitbit? The slide/lock idea is going to be hard to get in something that isn’t aluminum (like you mentioned). I went with the pin design in mine since they are super cheap as a watch band option and left the possibility of so many ways to customize it. 22mm is a standard watch band size, so that’s what I went with.
The case is pretty robust! I’ve been wearing as my daily watch since about mid-March. The weakest point in the design is the watch crystal that I have covering the display. I haven’t glued it in place yet since I’m still tinkering with different stain colors on different case designs. Once I have something I like, I will switch to a sapphire crystal for a little more durability. The bands and pins have never twisted out or anything like that. 
In terms of materials, I only tried with PLA. The woodfill, was a PLA mixture. It is actually weaker than regular PLA since there are bamboo particles mixed in. It is a relatively solid design with very few thin walls anywhere. I think the thinnest wall is the area between the watch crystal and the top of the watch, but it is still 0.4mm (so 4 layers in the print).
I actually just last week had a CNC company reach out to me about sending me a free mill for future projects (after they saw the watch post). So in the future I am going to try and mill some hardwood myself. Maybe even some aluminum and try and figure out a better antenna situation.
In terms of comfort, it feels like a normal watch. It is lighter than any smartwatch I’ve worn before and no bigger than an old analog watch I had in my drawer. The biggest thing for me in this project was to end up with a watch I wanted to use daily.
Other than tell time, it forwarded notifications from my phone. I attached a video I just took of a message from a friend. Because it can forward notifications from my phone, I have it set to parse certain notifications (like weather or calendar events) so I can look at those at any time as well. I use tap gestures to control it (I felt a touch screen was too small for a screen this size). So for example, if you want to see your next calendar event – when the time is showing, tap the left side of the watch and the calendar event pops out.
Things that I think I did well:
  • Hardware – I was very happy with the schematic and PCB layout. It was compact and no major booboos on the first pass. 
  • Software – I was very happy with how the display driver turned out. I had some horrendous FPS using a different micro (PSOC 4 BLE) that I improved significantly with this micro.
  • Casework – A round watch! All I wanted was a round smart watch that looked nice. I think overall, the design and aesthetic are right where I wanted them.
Things I could have done better:
  • Hardware – I could have added an ambient light sensor so I could automatically adjust the screen brightness. I chose not to because I didn’t want to have to light pipe ambient light in, I thought it would ruin the look of the casework.
  • Software – There are always more power improvements, and I’m sure I could improve the display driver some more if I really wanted to.
  • Casework – Sealing. Right now, the electronics are not sealed at all. I would make sure that the watch could at least be IP22+ in the future.
Still wearing it daily! I get about 7 days of battery life (on average, some weeks are better than others), so I charge it Friday nights typically. It needs about 2ish hours to charge to full or if you’re in a rush, about 1 hour to get to ~80%
I hope that helped! If you have any other questions, feel free to shoot them my way. I am very excited to see more makers out there. I am honored you would reach out!