Skip to main content

Wakey Wakey - Network Alarm Clock

I repurpose old Android mobile phones (from the KitKat/Lollipop era) to use as alarm clocks in my 3 young kids' rooms. After a while, it gets pretty tiresome syncing up the alarm clocks (eg. when the next day is a public holiday and you want to disable the alarm just for that day so that everyone can get a bit more sleep).

I thought it would be pretty cool if I could update all the alarm clocks remotely from a webapp. I couldn't find any alarm clock app that can be remotely controlled on the app store, so I decided to implement my own.

For the webapp, I repurposed another project of mine called Shopping Buddy. This turned out to be relatively easy, because it basically involved stripping away features like bookmarks and history, and trying not to break things along the way. It was done pretty quickly, and I called it Wakey Wakey. 

The production site can be found at:

The Github repository can be found at:

Screenshots:



Now I needed an Android app that can talk to the backend, download the alarm schedule and basically function as an alarm clock.

For a humble alarm clock app, this turned out to be more difficult than I imagine. Unlike a normal app, an alarm clock needs to do a lot of platform-native stuff, including:
  • running periodically in the background to schedule alarms
  • activate the alarm, even if the application is not in the foreground, or the phone is asleep
  • setup everything again after a reboot etc.
I initially turned to Javascript-based app development frameworks such as Cordova, which will require platform-specific plugins to implement the above functions. But there was no single plugin that provides all the necessary functions, and the ones available seem to be old and buggy, which will require a lot of tweaking and debugging before they might even be fit-for-purpose. So given the options available, it seems most sensible to go fully native instead.

I downloaded Android Studio 4.0 and pulled in code from a few alarm clock apps from GitHub, including the one from ASOP KitKat. I wanted to target SDK level 19, because I wanted the app to work with Android versions as low as 4.0. It came together slowly. I had prior experience on Android development with Java, and it was every bit as laborious as I remembered, nothing like the brevity and levity one feels when developing with a higher level language like Javascript.

The UI is extremely plain and simple. The client will turn the volume up to maximum, so the alarms will ring even if the phone has been accidentally muted or airplane mode has been switched on (yeah, I can't remember how many times my kids have done that to me).

Once an alarm goes off, it will continue for 10 minutes, or until the alarm is remotely disabled on the webapp. The code is actually there to dismiss the alarm by touching the screen, but I have commented it out!

Replication happens in the background to a local database, so the alarm clock will function even if wifi is down (provided the changes have already been replicated to the local instance before the network went down).

The Android client APK can be downloaded at:

The Github repository can be found at:

Screenshots:




 
Labels:

Comments

Post a Comment

Popular posts from this blog

Update: Line adapter for Ozito Blade Trimmer

Update (Dec 2021): If you access to a 3D printer, I would now recommend this solution , which makes it super easy to replace the trimmer line. I have been using it for a few months now with zero issue.
5 comments
Read more

Line adapter for Ozito Blade Trimmer

This is an adapter for Ozito 18V battery trimmer (and possibly some Bosch trimmers as well) that uses a plastic blade for cutting. It lets you insert a 2.4mm trimmer line (about 8cm long) and use that for cutting. Simply cut a length of trimmer line and briefly heat up one end with a lighter so that a little bulb is formed. Then insert the trimmer line into the adapter and slot that into the trimmer as per normal. Make sure the trimmer line is not so long that it touches the safety guard. If that is the case, simply trim off any excess with a cutter or scissors. This part is best printed using PETG, which is a tougher and more flexible material. PLA is more rigid and breaks more easily. However, even with PETG, it will still break when it hits something really hard. Since this takes only 0.5m of material and 15 minutes to print, I will usually print a batch of nine at a time at very little cost. The blades that they sell do not break when it hits a hard object, but ...
Post a Comment
Read more

3D Printer Filament Joiner

I have been looking at various ways of joining 3D printing filaments. One method involves running one end of a filament through a short PTFE tubing, melting it with a lighter or candle, retracting it back into the tubing and immediately plunging the filament to be fused into the tubing: One problem with this method is that you can't really control the temperature at which you melt the filament, so you frequently end up with a brittle joint that breaks upon the slightest bend. Aliexpress even sells a contraption that works along the same line. As it uses a lighter or candle as well, it suffers from the same weakness. I am not even sure why you need a special contraption when a short PTFE tubing will work just as well. Another method involves using shrink tubing/aluminium foil, and a heat gun: But a heat gun is rather expensive, so I wanted to explore other alternatives. The candle + PTFE tubing method actually works quite well when you happen to melt it at the rig...
2 comments
Read more