New book: Making Android Accessories with IOIO

My new book, 'Making Android Accessories with IOIO' is out on Amazon now.

Its a small project-based book, that gets you started using IOIO boards.

IOIO boards are interface boards that allow you to connect electronics to your Android phone or tablet.

Although IOIO will work with Google's Open ACcessory standard, it will also work with the much older ADB standard which means that almost any Android phone will work with IOIO.

IOIO will work with either a USB cable or using a low cost Bluetooth USB dongle, making it great for robotic control applications.

Projects

Here are the projects that you can build using the detailed step-by-step instructions in the book. Each project description includes a parts list.


PIR movement detector - sends an SMS when movement detected.

Temperature logger - to SD on the phone, Bluetooth or USB

LED Matrix - 8x8 multicolor LED Matrix, with animations

Bluetooth rover

All the source code for the projects is provided on the book's website.

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Freetronics USB Droid Review

5 Stars! The best thing to come out of Australia since Rolf Harris!

I was given one of these boards at Android Open, and rather like the IOIO of my previous Blog, I have only just got around to having a play with it.

It is intended as an alternative to the Android ADK reference board which is Arduino Mega-based and so probably overkill for most Android Accessories that you are likely to make. The USB Droid is far more practical in size.

It comes in a nice retail pack, with a Mini USB lead which is used to connect it to your computer rather than the 'normal' Arduino USB-B connector - good choice.

And that is where the magic starts...

The board is extremely well made, and well thought out. When I plugged the Mini USB into my computer I was surprised to see a green LED light along with the blue power LED.

The green LED is labelled VBUS and yes, the USB 5V is passed through from your computer and out of the USB-A connector to your phone. A really nice touch as you don't have to use an external power supply while you are developing.

I am not sure Putting a Micro SD card on there is much use for making Android accessories, as effectively all the storage of the phone is available to you. But I guess you could make a data logger that worked off-line until you connected it to the Android phone to send the data to Pachube. Also it could come in handy for other types of USB host projects.

I have a minimal Android Open Accessory test app that I describe in my Arduino + Android book. You can download it from here (the app that is, not the book). There are also slides from my talk at Android Open here that describe the app. All it does is send a number to the Arduino that increments it and sends it back.

The sketch installed and ran perfectly.

I am very impressed with this board,  its certainly a lot neater than an Uno with a USB host shield on the top.

I see that Freetronics have done similar things with an Ethernet board. I look forward to trying out one of these.


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IOIO First Impressions

I picked up a IOIO (apparently pronounced YoYo) from Android Open and I have just had chance to play with it.

Unlike the Arduino, IOIO is not intended to operate independently. It has to be paired with an Android phone. While it can use the Android Open Accessory protocol, it can also use plain old ADB which means that it works on most phones rather than the smaller choice of phones that Open Accessory works on.

I even tried an old Android 1.6 LG phone that one of my kids cast off six months ago and it works just fine.

When creating a project, you do not change the firmware on the IOIO, but rather you issue commands that read values from pins and turn pins on and off from the Android app.

It took 10 minutes to get the example working that turns the on-board LED on and off from a little Android app. Although I had Eclipse and the Android SDK already installed. These are probably the most complex part of setting up.

IOIO sets out to do just one job and do it well. It is not a general purpose board like the Arduino, and for $50, it is just cheaper than an Arduino and USB host shield and smaller and neater.

I like it a lot and it looks great. Far more IO ports than you are ever likely to use. In fact, I will probably solder 0.2 inch screw terminals onto the connectors and just use make every other IO available.

Pros.
Pot to adjust charging current to phone
Nice looking board
Good documentation set on the Wiki (https://github.com/ytai/ioio/wiki)

Cons.
Only 20mA output current per IO pin (Arduino can do 40mA)
3.3V logic, but some pulls can cope with being pulled up to 5V
No Power socket, you have to solder power leads on. This means that to do anything with the board, you will need to solder.

Edit: I forgot to mention that IOIOs with the latest firmware can accept a cheap Bluetooth dongle and work seamlessly over BT. Even switching connection without restart if you plug in with USB.


About the Author
These are my books. Click on the image below to find out more about them.

Arduino + Android Projects for the Evil Genius

My new book 'Arduino + Android Projects for the Evil Genius' is now available for pre-order from Amazon. See the link to Amazon in the right-hand panel (scroll down a bit).

The cover on Amazon hasn't been updated yet, so it looks a little different.

The first books should be shipped around the start of December.

The projects are:

Chapter	Project	Notes
1	Bluetooth Robot	Control a small rover from your Android Phone using Bluetooth and an Arduino and Motor shield.
2	Android Geiger Counter	An Android Open Accessory Project using a USB host shield and Arduino Uno.
3	Android Light Show	A powered Open Accessory dock for your Android phone that drives three LED panels to make a sound sensitive light show.
4	Android TV Remote	Programmable Infrared remote control accessory for your Android phone.
5	Temperature Logger	A temperature logger that uses the Android phone to wirelessly send readings to Pachube.
6	Ultrasonic Range Finder	An Android Open Accessory for measuring distance.
7	Home Automation Controller	The Android tablet base unit with a audio jack interface to Arduino.
8	Home Automation Power Control	Add control of AC outlets and lights to the Home Automation Controller from Chapter 7.
9	Home Automation Thermostat	Add control of domestic heating to the Home Automation Controller using low cost RF data modules.
10	Remote Door Lock	Control access to your home using RFID tags, also with a RF link to the Home Automation Controller
11	Ethernet Flag	Network control of two flags that can be activated from any Internet device. Useful for the Evil Genius to summon minions.
12	Delay Timer	A simple to make Arduino-based delay timer.

About the Author
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Android Open Accessory without charging the phone

I have been spending some time recently working on Android Open Accessory using an Uno and the Sparkfun USB host shield. I'm including a range of accessories, Geiger counter, ultrasonic distance meter etc. in my soon to be released (well Dec 2011) book Arduino + Android Projects for the Evil genius

Although the feature that the accessory should provide half an amp at 5V to charge the phone is all very well for AC outlet powered accessories, it means battery powered accessories need a big battery.

Or does it?

I decided to do a bit of experimenting with a surplus USB extension lead that came with a USB modem dongle and just extends the USB lead a couple of inches.

Firstly simply cutting the red 5V USB power lead. This stopped the accessory being recognised and the charge indicator on my Nexus One did not indicate any charging (no surprise there).

If, however, I put a 1k resistor in line on the red 5V wire, everything works fine as an accessory, but the phone does not draw anything significant from the accessories battery, allowing it to be powered from a small 9V battery. At least it does if the phone is well charged.

WARNING: This result was derived experimentally. This may well void your phone warranty, if you connect it up like this. It didn't hurt my phone, but do it at your own risk. Also your wire may not use the same color coding as mine did, so red might be the wrong lead for you.

The following sequence of photos shows the construction of the lead.

Carefully cut away some of the outer plastic with a sharp knife on one side and tease out the shielded bundle of wires.

Scrape a gap between the shielding to get at the +5V wire.

Cut the red wire and strip and tin the ends.

Solder the 1k resistor into place. Then wrap it all up with insulating tape. Wrap the part behind the tape carefully, so that there is no chance of the bare leads from either side of the resistor making contact with the shielding wires or foil.

About the Author
These are my books. Click on the image below to find out more about them.