Sunday, January 27, 2013

Remotely operated rover - Andoid and IOIO Basics

When I first started the project, I had never written an Android program before. I've built simple Atmel-AVR and Basic Stamp robots, and usually the first thing you do is make sure you can blink an LED from the microprocessor - it's "Hello, world" for micros. First, I needed to get the compiler up and running for Android, and understand something about how Android works.

I started with the excellent Android dev tutorials and worked through the first few programs. I then followed the tutorial at Sparkfun to get the IOIO sample projects working, and tinkered with them a bit. I found that the IOIO worked great on my Galaxy Nexus and Kyros 7127. My older Droid X2 needs the USB connection set to "charge only" to work. I plan on using the Droid for the rover. I am pretty impressed with the design of the development kit for Android, and extremely impressed with the IOIO. A great deal of thought has gone into making it easy to program for and interface things with.

 I first experimented with the Hello IOIO application, which runs a GUI application and a thread to talk to the IOIO. It worked fine, and is a great way to test the IOIO on your phone. The Hello application let's you turn an LED on the IOIO on and off from the phone.



 The sample programs also include a sample service, that runs in the background and only communicates with the user via statuses. I decided this was the way to go for controlling a rover. Android apps have life cycle that you must track to deal with incoming calls, screen rotation, and other events. That actually tears down the program and restarts it, and your program has to deal with it. This is not ideal for a realtime control application.

The service makes it a little trickier to provide feedback and debug, but you can use the logging feature to get what you need. A robot or rover will be talking to the user over the network anyway, right? :-)

 The next step was to decide how to handle the networking aspects, which proved to be very interesting. That will be the topic of the next post.

3 comments:

  1. Thanks so much Jason im engineering student and developing this as a final year project Android Vehicle with Live Streaming and this blog is really helpful. Thanks Alot! for uploading these :D

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  2. You are quite welcome. Good luck with your project!

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