mackuba/smogwatch

watchOS app for checking air pollution levels, created for my blog post series

SmogWatch

This is an app I'm building for my blog post series "WatchKit Adventure". Its goal is to display the level of PM10 smog pollution (fetched from a local monitoring station) on the Apple Watch's watch face. Initially it only works for a single preset station in Kraków, Poland.

The second goal is for me to learn programming for watchOS and also get some experience that I can share in the blog posts :)

Installation & Running

If you want to try out the app, clone the repo (or download a zip) and open it in Xcode. There are currently no external dependencies, so just build the project.

Running a watch app in the simulator is about 100x easier than getting an actual device to cooperate, so try that first. Then, to run on the real watch, you will probably need to edit at least the developer team and the app ID. If you manage to run it, let me know what else you needed to do :)

The app currently uses http://monitoring.krakow.pios.gov.pl for the data and has a hardcoded ID of PM10 parameter on the Kurdwanów station. If you want a different station (as long as it's from the Małopolska monitoring system) then open the site in the browser, select only PM10 parameter only on one selected station, load the data and check in the web inspector what parameter was sent in the request. The query in KrakowPiosDataLoader.swift is the place you need to update.

Yup, it's all very very rough right now - did I ever say this was a finished app? It's basically version 0.0.1 :)

It's possible that there are other regional monitoring systems in Poland that use the same API, so let me know if you find one.

Complications

The part that's working so far is complications. Not all families are supported, currently Modular Small works best since that's what I primarily use (on Modular or Siri watch faces). If you really want to use a different complication that isn't supported yet, look in ComplicationHandler.swift, and also enable the complication family in the target settings.

Main UI

The app itself has currently no UI whatsoever, so if you see a black screen, don't worry, it's not broken. First things first, you know...

Credits

Copyright © 2019 Kuba Suder. Licensed under WTFPL License.

I've made the code available under WTFPL because the whole idea is for other people to be able to learn this stuff together with me and reuse any pieces they need from my app to build their own. So take what you need and build cool shit, and don't worry about licences. Of course if you want to mention me somewhere, I'll be very happy :)

smogwatch's Issues

can't show PM10 data on Apple Watch

I try with same parameters on Postman, which works. and then I hardcode those params for Apple watch extensions as show above, but failed to fetch data on apple watch.

Tried your app, works on simulator but no background refresh on device

Hi!
Thanks for sharing your code. I've run into it because I'm trying to do something similar (getting data from a website to display on the watch and a complication, without an iPhone app running).
I've installed and ran your app, it works 100% on the simulator, but on my device (watch 4 44mm running 5.1.3) the background refresh is scheduled but never happens.
Have you managed to run your app on a device?

How can you use URLSession in a background refresh task

I am writing a weather application which should provide some complications and after watching the WWDC video the slide at 20:51 states that you cannot use URLSession in a Background App Refresh task. If I understand your code, this is exactly what you do though and I would like to know if you had any problems with this?

AFAIK, the documented way to do this is schedule a url session background task to download the json, then decode it and store it (in your case in user defaults) and in the extension delegate's handle(:) schedule the next background task and reload the complications.

OpenSense Sensor data

Hi, I'm trying to build my first Apple Watch app based on your project. I want to eventually add more features, so that user can choose the base station (or better yet data is served from closest one). I would like to use sensors from opensensemap. They have a simple API which I can query successfully from Postman, but I don't have experience getting data with swift.

I can't read these two values: lastMeasurement.value and lastMeasurement.createdAt

Could you please give tips on how to modify the KrakowPiosDataLoader.swift so that it would work with a basic JSON? Thank you.