Creating a Arduino-powered smartwatch


Hi, now that I’m almost finished work on my previous project (a proper raspberry pi laptop), I’m looking to move on to another project.

'Wearable’s seems to be the word on everyone’s lips at the moment, and so that’s definitely an avenue I want to try my hand at. Lots of people seem to be making funky flashy jumpers at the moment but I want to try something different. i’m talking about real wearables. I want to do make a smartwatch.

I’m going to start off by just having it display the time, and then move on to bigger and better things. I’m going to need a screen - I’m planning on using either the Nokia 5110 LCD or the Adafruit OLED unit. It looks as as if the OLED is the most power-efficient, which is obviously important (although the backlight won’t be on all the time), but I also need to consider how many pins are needed to drive it, as I need to have a teensy microcontroller.

That brings me on to the next point - which microcontroller to use? The ones I’ve seen so far which look viable are the Adafruit trinket, the Adafruit gemma, and the smaller official Arduino boards. It needs to be small, but with enough oomph and pins to drive the LCD, a bluetooth module, maybe a couple of buttons, and hopefully a Neopixel - maybe even a ring round the edge.

What are your thoughts? What do you think would work?

I’m still learning :)





Sounds like a fun idea! - There are quite a few digital watches out there and they all have similar issues the major being battery life. You could try and integrate weather sensors to a rain coat and have a micro digital display giving live weather feed, i guess this wont hog the battery… something fun i guess *a talking point down the local pub.

:) - if you decide to make a watch post some pictures of your progress!


I’m going to be controversial and dive right in here and suggest that you might want to give the Parallax Propeller a look.

It wont be cheap, it wont be easy, but I’d bet it would make an awesome smartwatch core!


Love the video on that website! haha A day in the office does not seem so bad in that company !
That mini board would be awesome for a smartwatch.


That does look good - but it is going to be a mighty-steep learning curve for someone like me who is a beginner of all trades, but a master of none. As long as I ensure it’s mostly compatible (or failing that cheaply upgradeable) then I can start with something really simple, and upgrade at a later date.


Battery life will certainly be an issue. I was planning on using one of the tiny Adafruit LiPos, as they’re small, interchangeable and quite cheap and also support various bits of USB charging kit so that I could make a completely (or very nearly) self contained system. The current ideas I have to lengthen battery life as much as possible include:

  • Try and have a really low power display
  • Have the backlight, or maybe even the whole display be turned on/off at the touch of a pushbutton, whilst using a RGB LED as an indicator
  • wire a long JST extension lead into my most-used jackets/coats and keep a bigger (like 2000 mAh or something) battery in the pocket.

I also think that it should have a rumble motor in it to alert the wearer of texts etc. I might try my first 3D-printed case for this project - it seems like a perfect opportunity. We have a 3D printer at school, so I can easily get access to that as I currently don’t have a spare grand lying around for that kind of thing!

I will certainly post pictures, code and maybe even build instructions for both this, the Pi-Laptop, and some other projects I’m working on on my blog, and probably some pictures in this thread for this project.

Thanks for your replies :)


If you can get hold of them, that sounds awesome.

For my most recent project, I tried to use a Li-Po battery from amazon, but unfortunately, my order was blocked due to some new EU regulations. I tried sourcing them from cool components (a UK based firm), but they wanted something like £15.00 courier delivery on top of the cost of the battery - it just wasn’t affordable.


Hmm, that’s annoying.

Maybe that’s why the Adafruit Lipos have gone from the Pimoroni shop.

I wonder why small batteries are so bad?


Have you looked to see if your local model shop has any suitable LiPos? Maybe some of the ones used for indoor planes or helicopters might be suitable?


Good idea, actually. I tried that last week, but unfortunately they didn’t have any in stock.

Definitely worth a go, nonetheless.


Yes, I’ll try that next time I’m near a model shop. I’d still rather support the maker community, but it would do until I can get some from a dedicated ‘maker’ shop.


Hmmmm. Just discovered this round LCD. It’s 1.8" big (I assume diameter) and also you can see it a bit even with no backlight, so it would be annoyingly perfect for a smartwatch. That said, it would presumably be a nightmare to drive, with little documentation and certainly no tutorials for it working with (insert microcontroller here). As it’s a full blown colour LCD I would also need a much beefier CPU/GPU (I’m thinking raspi) to drive the kind of graphics and stuff I’d want if I went to all the bother of having an LCD.

Could be interesting though.



That’s a seriously cool LCD, but I can definitely see it being a total nightmare to drive.

I’m a huge fan of the Nike Fuel band, which uses a 5x20 pixel single colour LED display and a really shiny single row of 20 coloured LEDs from Red to Green. Amazing how much you can do with such a simple display, I wish they sold them ( and the other parts ) on breakouts.


check out the tiny screen and their boards!


They’re cool, but I’d feel that I was slightly cheating, using hardware that was probably designed to do exactlying what im doing. That said, I may have to pick up a few of them and have a play!


The Fuel bans looks very cool. I’ve just picked up a pebble, and it’s honestly one of the best pieces of consumer technology I’ve got in terms of usability. Adafruit do one smallish e-ink kind of thing (the SHARP memory display breakout ) but it’s not cheap at around £50+ this side of the pond, and I fear that it won’t be nearly as good as the high-res ePaper on the pebble. It also needs a shedload of RAM to drive, which is not ideal for a tiny low power watch! I think eInk/ePaper displays are one of those things that in 2 years time will be common among makers.


I’d be inclined to agree. The watch doesn’t try to be anything more than it is; it tells the time well and pings notifications from your phone onto your wrist. I’m a fan :)


sorry for late reply just saw this and thougt i’d help.

If you want adafruit lipos in the uk 4Tronix is really great and much cheaper than anywhere else I have seen :)


Ooh, that looks good. I’ve resorted to buying them on eBay from Singapore and China now - I haven’t used one yet as I’m still awaiting the charging boards to come. It was something like £5 for a pretty big one (3000mAh), which isn’t bad. It doesn’t have a connector on it which is a bit of a pain and it took a couple of weeks to get here, but it wasn’t expensive to ship and was a good fit size-wise for my project. I haven’t managed to find any of the really big blue ones (that have 3 cylindrical cells in them), which is a shame. They’re nice and cheap though.


I realise this is old now, but how did you get on? Gemma is driving me nuts. Did you work with gemma at all?