Controlling Arduinos from a mobile phone can be a challenging task. The amount of effort that’s required to program an app often isn’t worth it. So when Blynk was launched on Kickstarter I was really excited. Blynk is a mobile app which lets you control Arduino or Raspberry Pi using ethernet or wifi. The well thought out interface lets you create dashboards of virtual buttons, sliders, and other widgets to not only send requests but receive and display data.
Arduino libraries are provided to interface with the app and are bundled with a good selection of example scripts to get you started.
Once connected to the network the app asks you to create a dashboard where an authentication ID is generated for you. After pasting this ID into the Arduino script you’re able to make a connection. I was using an Arduino Uno with a standard wifi shield and was able to make a connection without any snags.
From here you can add Controllers, Displays or Notifications. We’re told that more of these will come, but there are enough to satisfy most situations.
Controllers: buttons, sliders, large sliders, timer
Displays: Value, LED, Gauge, Graph, Terminal
Notification: Twitter, Push notification, Email
I created a circuit a while ago to control remote plug sockets, activated by a PIR sensor (motion sensor) and LDR, and wondered if I could build on it to make it mobile-controllable using Blynk. I had something up and running in around 15 minutes. Not only could I control the plug with a virtual toggle button but I could also return the value of the LDR in a graph plotted by the second.
Blynk’s communications go through their remote servers and I would have expected some delay, but the response time was incredibly quick. There was no difference in delay to that of the remote control the plugs come with. If, for whatever reason, you’d like to run the server yourself all of the code required is available on Github.
The app is free for Android and iOS with premium widgets available for purchase (soon). This makes it a very cost effective solution and my personal goto for situations where I need a mobile interface.