Android + Arduino project: should I have them talk via Bluetooth or USB?

Question

I'm starting a project where I'm going to try to write a program for Android that will control and/or send/receive input to/from an Arduino gadget. Like, make an LED light blink, as the simplest example. I can either get a Bluetooth shield for the Arduino board and go the Bluetooth route, as per the example Androino! Control an Arduino from your Android device using a cheap Bluetooth module.

Or I can buy a USB host shield for the Arduino board and have the phone talk to the Arduino device via a USB connection, as per the example Adventures in Android ADK Development: Hardware.

Which implementation option is easier and more foolproof both from hardware setup (soldering? compatibility issues?) and programming perspectives (additional Python scripting required? 'listening' on Android for a Bluetooth device vs. a USB device and sending data back and forth?) I've been doing Android development for a couple of months, but I have NO experience with Arduino.

I don't mean this to be a lazy question - I'm able to do the research, but I'm inexperienced and am trying to choose my implementation right away so I can order the right hardware stuff in time for a deadline. I have to make sure I choose an implementation I can actually DO.

EDIT: Might it be easier still to use an ethernet shield on the Arduino board and have the Arduino gadget talk to the Android phone via TCP/IP? I don't know why this didn't occur to me from the beginning. But there seems to be far less in term of tutorials on this kind of implementation, for reasons I'm unsure of.

Answer 1

I am currently working on a project that interfaces an Arduino and an Android phone via bluetooth. And from my experience so far all I can say is STAY AWAY!

All the articles online about cheap bluetooth modules working perfectly are highly misleading to say the least. It might be easy and perfect if you buy an $80 shield, but not if you're on a budget. I bought a $30 shield and it only seems to work on one of the seven Android devices I have tried to use. Furthermore, it seems completely unresponsive to the standard bluetooth connection methodology and requires a host of workaround/hackish method calls that are all highly unsafe and unstable.

On the other hand a USB connection is far more reliable, better supported and of course has the inherent advantage of speed and since it is well supported does not suffer from all the pitfalls bluetooth connectivity does. It is just as easy to setup from a hardware perspective (no work required if you get a decent shield), reasonably priced compared to bluetooth shields and in my experience generally easier to code.

If you are on a budget and can do with a hardwired connection I highly recommend USB over bluetooth.

Answer 2

I don't know the details of either. But I would say if the phone is going to stay with the board then use USB. For lower latency and in general, I find a hardwired connection to be better for all applications.

Answer 3

I have no experience in Arduino and some decent experience in Android and I decided to get the usb connection to work from the phone to arduino to light up the led.

I used a Nexus One and an Arduino Mega ADK and I got the usb connection working in around 5 hours of tinkering and I was absolutely excited to get the led to light up when I clicked a button. But then I decided to go to the next level because bluetooth sounded way too cool to pass up.

Anyways around 30 hours later I FINALLY got it working and I can say it was COMPLETELY worth it. There was a TON I needed to learn, but once I got it working I can say it was not all in vain.

I bought the Bluetooth Itead V2.2 shield ($25 for me) then connected it to my arduino and used my Nexus One with Amarino to send a signal to my chip and turn off and on the led.

http://iteadstudio.com/store/index.php?main_page=product_info&products_id=468

From my experience it was definitely difficult, but the learning curve is what makes these projects so fun. So I would say GO FOR IT!

Good luck in your future works!