The Alesis IO Dock is a great product for iPad musicians – this small hack makes it even greater. It overcomes one limitation of the IO Dock: You can’t simply hook it to a USB hub. So I decided to build in an additional hub – which allows me to hook up additional class-compliant interfaces like my M-Audio Axiom master keyboard, and power them via the hub.

Yes, it works. No, it hasn’t been thoroughly tested yet. So try at your own risk.

The hack isn’t too sophisticated or demanding. Yet there are a couple of things we need to discuss before going to the step-by-step description. I’ve also tried to answer some questions that might arise in the FAQ.

What we’re doing:

We’re smuggling the USB hub into the connection between the iPad and the IO dock. (The video explains why.)

What you need:

• A USB hub. Edit, 4-Jan-2012:  After giving it some more consideration I think that you might start with a normal hub rather than a powered one. (I used a powered hub Belkin F5U404.) This has certain limitations, though. Why? USB knows two basic types of port power – normal USB ports are supposed to deliver a 5V supply current of up to 100mA. That is enough to power simple interfaces and USB sticks. It is not enough to charge your phone, or to power a USB master keyboard.  So using a hub without power supply would normally mean that the iPad is not properly charged – but the way the iPad charges is actually hard-wired in the IO Dock’s iPad connector, so the iPad will charge even without a powered hub. (It is connected to the USB port’s input rather than to its output anyway).  IMPORTANT: As we will be using the IO Dock’s power supply, there are some limits to what we can drive with our hub. Please: See the FAQ. And I’ll have a more thorough look at the IO Dock’s power supply circuitry soon.
• The hub’s connector cable. These cables have a flat A-type USB plug to go into your computer, and usually a micro-USB B-type plug like the ones for charging your phone (if you don’t have an iPhone, that is). We are going to cut up this cable and configure it to supply and interface the hub within the IO dock.
• 2x 1.27mm 2mm grid pinstripe connectors – one 6-pin male, one 6-pin female. If you can, get connector strips with turned sockets; you can use them as plug and as female connector, like these ones. The original connector is like this one: [sample]
• A small 100uF/6.3V capacitor - or something along these lines – as a buffer for the hub’s power supply. If you haven’t already, see the FAQ.
• Basic soldering tools and skills. 
• A Dremel tool to cut out a hole for the additional USB ports in the IO Dock.
• Glue to fix the hub within the housing – I used a run-of-the-mill hot glue gun.
• A class-compliant USB device for testing. (What’s that? See the FAQ.)
• Approximately 2 hours to do it.

So let’s get started!

It’s possibly a good idea to check whether your IO Dock has the latest firmware, and update, if necessary. Latest known version is v1.0.7. Earlier versions have been known to contain bugs.

First soldering task: solder a female connector to our mini-USB connector cable. Getting the pins right is easy – the cables are colour-coded, so just solder them in the same order as they are with the IO Dock’s internal cable. From left to right: (1) Red/5V (leave unconnected), (2) Red/5V, (3) White/D-, (4) Green/D+, (5) Black/GND, (6) cable shield.

To keep things simple, I just soldered this cable to the hub’s board. You could just as well make a cable from remainder of the USB connection, with the plug, and plug it into one of the hub’s outputs.

You see that I soldered in an additional wire: it connects the hub’s plug for the power supply (the plus line, that is) with the IO Dock’s +5V supply line. This is a bit dodgy, technically speaking: I had done a litte workbench test with the Belkin hub I’m using and noted that it worked almost too well: my iPad was still charged, now through the hub’s +5V power supply. So I simply replaced the external power supply by a connection to the IO Dock’s internal +5V bus.

So the iPad gets its supply current through the input plug of the Belkin hub now. If this does not work with the type of hub you’re using, you may have to cut up your hub’s connection to the input plug’s +5V terminal and rewire it to the +5V of the output plugs.

Whatever you do: don’t forget to solder in the buffer capacitor on the +5V line. I did, so it’s not in the photo yet.

In my case, I cut a hole that was 52mm wide and 8mm high, 17 mm from the lower edge of the IO Dock. BTW: Don’t turn the Dremel up too high, or you will melt the plastic rather than cutting it. Go for a rather low speed setting.

Just to remind you, this is what we’re doing:

After sticking it together – maybe try a little workbench setup first – test it: Does the IO Dock still work? Does the iPad still charge?

If the iPad doesn’t charge, you need to solder an additional power supply wire from the hub’s power supply input (where you soldered the single connection wire, you remember) to the USB micro plug’s +5V port.

The putting it all together thing in a short video.

FAQ

One of my Evil Mad Scientist skills: Reading your mind and coming up with the answers for the questions you haven’t even asked yet. Muhahahaha!

Does it work with my [insert gadget here]?

It will, as long as the USB device is class compliant. That means: It follows a standard that the iPad and other computers know, so that there are no additional drivers needed to get it running. A USB-to-Midi interface, for example, or an audio interface, a USB keyboard, or a foot controller. It might not work with the fancy flux compensator control you just bought on eBay, along with a floppy disc holding the drivers. Take a look at this device list over at iosmidi.com.

Another consideration is how much power the device needs. We’ll get to that in a minute, for the moment just remember that you probably shouldn’t defile the IO Dock by hooking up a mug warmer or a fan to it.

Is the IO Dock really capable of powering three additional USB loads?

Good question, actually. No, really. You may know that an iPad charging can draw a pretty hefty current – 2.1A, as far as I know. The IO Dock’s power supply is capable of delivering up to 3.0A, so wiring three 500mA loads to it – a USB/Midi keyboard, a Maschine-type controller, and a light – will drive it over the edge. Well, sod and burn the power supply, but the IO Dock’s internal supply voltage comes from a regulator,  and you wouldn’t want to burn that.

In my first experiments I hooked up a device that, while switching on, seemed to produce a spike current that demanded just a little bit more than the hub could supply – and this caused the hub (and the dock) to lose its power. I drew three observations from that: (1) Better add a buffer capacitor for the hub. (2) If you switch on the IO Dock with the load already connected, it works. (3) The IO Dock’s internal regulator is possible short-circuit proof, but no guarantee for that. It may still burn.

Scared now? You should be. I’m pretty confident that you are OK with one 500mA load (i.e. one device that only works on a powered hub, not on the camera connection kit itself) and two small loads like MIDI interfaces, but don’t blame me if anything goes wrong. We’re absolutely doing this on our own risk – I do, you do. Consenting adults, you know. 

Does the USB port for connecting the iPad to a computer still work?

Oddly enough, no. Which makes it all the more surprising for me that the hack actually works – a normal IO Dock seems to drive the iPad as slave rather than as a master, so once you force the iPad to be master, it won’t sync. (Theory.)

What the IO Dock still does when you plug it into a computer: It registers as an audio interface. Here what a Linux machine tells me:

[14339.660194] usb 5-1: new full-speed USB device number 2 using uhci_hcd
[14339.818328] usb 5-1: New USB device found, idVendor=13b2, idProduct=0020
[14339.818343] usb 5-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[14339.818353] usb 5-1: Product: Alesis iO Dock
[14339.818363] usb 5-1: Manufacturer: Alesis
[14339.866455] usbcore: registered new interface driver snd-usb-audio

Does the IO Dock’s MIDI and Audio interface still work?

Hell, yeah! That’s what it’s all about, isn’t it?

What if I don’t want the hack any more? Is it reversible?

Yes. Just unplug the hub, replug the IO Dock’s USB connector plug, and everything is the way it used to be. That’s why we did it with connectors rather than with the usual brute-force cut-the-wire-solder-it-in-to-hell-with-tomorrow approach.

You can even try it out before cutting a hole into the IO Dock’s housing. I did this in my proof of concept.

I’m scared of messing with my shiny new IO Dock.

Well, then this is not for you. And did you know that there is a huge sticker on the back of the IO Dock warning of the shock hazard if you open it? Dangerous 48 volts of phantom power inside, you know…

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• Proof-of-concept: Alesis IO Dock bekommt einen Hub (Sonntag, 30. Dezember 2012; Schlagworte: IO Dock, iPad, Modding, Musik, Synthesizer, USB Hub)
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