Solving accessory incompatibility issues with the latest iPhone/iPods
This guest article was submitted by Andreas Ødegård.
Apple is notorious for making changes that break compatibility with current accessories. A few years back they removed the topside dock port in favor of a 30-pin bottom connector – a change that was actually needed. The changes they’ve made to the newest generation of iPods as well as the iPhone 3G, however, can’t be said to be very useful, breaking compatibility with various accessories – especially chargers."This accessory is not made to work with iPhone" is a message many people have seen since the release of the 3G version, but what exactly does it mean?
There are essentially two charging-related incompatibility issues in the newest Apple products as well as some incompatibility regarding line-out, microphones, Nike+ equipment, radio remotes, in-line remote controls, and AV (audio/video) out cables. These issues are all related to various changes Apple has made to the devices, all of them seemingly motivated by the desire to make money more than anything else. Read on for a list of incompatibility issues you might encounter as well as solutions to some of them.
First off, you have the issue regarding AV cables: cables used to connect to a TV. In previous generations of iPods, this was handled through a 4-pin 1/8-inch jack plugging into the headphone port and giving you some sort of AV interface in the other end, like S-video or RCA (three plugs: red/white/yellow). This is a fairly simple cable and it wasn’t long before you could get fully working cables for a couple of bucks from third-party manufacturers. This, of course, costs Apple money since they’d much rather have you spend $50 on their official cable.
What they then did is to make the cable work through the docking port instead; they also included an authentication chip. This chip basically tells the iPod/iPhone whether it’s a real cable or not; without the authentication, you won’t get an AV signal. To make things worse, there isn’t a cheap workaround to this problem. There are third-party cables available but they will still run you a bit of money, and while cheap unlicensed Chinese ones do exist, they often only work until the next firmware upgrade (when Apple has found a workaround for the fake chips).
The second incompatibility issue introduced in the newest generation of devices was the addition of a trigger-circuit for line-out cables. For those that haven’t used line-out cables for iPods before, these are cables that plug into the dock connector of the iPod and give you a clean audio signal that hasn’t been amplified by the iPod. The point of bypassing the iPod amplifier and running the signal directly to an external amplifier of some sort – be it a headphone amplifier, a car stereo, or a Hi-Fi stereo – is to give you better sound quality and a steady signal. You cannot, however, use it directly with headphones because there is no volume control when using line-out.
The way Apple restricted this little feature is very similar to the AV cable, but it's not as sophisticated. In earlier generations, all you needed was a dock connector with three wires going to ground, left channel, and right channel and you were set. I myself made several of these cables back when I had a first-generation iPod touch and had no problem making them work. That however changed in the newest generation and my current second-gen touch doesn’t work with any of my homemade cables.
The reason for this is that the devices now require an accessory detection to activate line-out. The dock connector has a pin that’s made specifically to allow accessories to identify their use through different value resistors connected to the pin. Basically, a docking station can tell the iPod/iPhone that it’s a docking station and the device will allow line-out to be used. Most brand name accessories already have this identification circuit for other reasons and so compatibility with them isn’t broken; however, cheap accessories as well as homemade ones don’t have this trigger circuit and therefore don’t work.
If you want to make your own line-out cable, there are places (e.g., Ridax) that sell connectors for DIY use. Some forum members over at Head-Fi reversed-engineered the new line-out cables and found that bridging pins 11 and 30 on the connector as well as pins 21 and 30 using a 1kohm resistor will allow the second-generation touch to use line-out. This seems to also be working on the other new iPods as well as the iPhone 3G, but I haven’t tried this myself so I cannot say for sure.
This isn’t an incompatibility issue that concerns newer generation devices but rather the previous generations. Many companies now sell microphones to be plugged into the iPod to use for voice recording, such as the brilliantly designed ThumbTack. These, however, only work with the second-generation touch and the fourth-gen nano because they need some special hardware and software. Bottom line is that if you have an older iPod, these will not work. iPhones, of course, have a microphone built in and don’t need external ones.
Quietly introduced with the newest generation devices and less quietly made crucial with the third-generation shuffle, Apple added an in-line remote control to the iBuds as well as the new in-ear earphones. Unlike traditional remotes that have one button for each control and connect to the dock connector, this remote works through the headphone jack and uses button combinations (hold, double tap, etc.) to allow you to control the device from a remote that’s barely thicker than the cable itself.
The remote works on the second-generation touch, fourth-gen nano, 120GB classic, and the new third-generation shuffle. None of the older iPods will work and neither will any of the iPhones for some reason, possibly because they use the fourth pin on the jack for headset microphone (don’t quote me on that).
The Nike+ system is something Apple introduced back in 2005, and it’s basically a small accelerometer that you attach to your shoe and then lets you track your running/walking on the screen. Unfortunately, the system doesn’t work on all devices. Using a receiver included in the kit, the system works with all four generations of the nano, but none of the hard drive models (most likely because Apple doesn’t want you running with a hard drive player). The sensor also works with the second-generation touch, in which case you don’t need the receiver because it's built into the device (the transmitter is available by itself as well as with the kit).
The Nike+ system doesn’t work with either of the iPhones or the first-generation iPod touch . . . without any good reason. The system uses a proprietary Bluetooth profile (this is why the second-generation touch will have Bluetooth capabilities in 3.0 – it has a Bluetooth chip already), which means that there’s nothing stopping Apple from enabling it on the iPhone. The hardware is there, and the software is there. For the first-generation touch, nothing should have stopped them from making it work by using the receiver that the nano uses, but I guess that making it a new feature on the second-gen touch was another reason for people to upgrade.
There's also a wireless Nike+ remote control watch that uses the same receiving system as the sensor and so it has the same compatibility. Bottom line: if you’ve been looking at this system, be aware that you need a second-generation iPod touch or a nano to use it. I’ve used this myself for a couple of weeks now and highly recommend it even if you only use it for walking.
Like the Nike+ system and the in-line remote, this is another official Apple product with some issues regarding compatibility. Unlike many third-party radio remotes, which are basically remotes with iPod-powered radios, the official radio remote from Apple needs the iPod to provide the software as well as the power and therefore won’t work with models unless Apple includes the necessary software.
As a result, the radio remote only works with the fifth- and sixth-generation original iPod (iPod Video and iPod Classic) as well as all four generations of the nano. None of the iPhones or the iPod touch versions will work with this accessory. If you want radio on the touch or the iPhon,e you either have to use Internet radio or buy a third-party radio remote that will work as a standalone iPod-powered radio (preferably one with a display).
Generic USB Chargers
When it comes to actually charging the devices, there are two limitations set by Apple. The first is a “"feature" that doesn’t allow the devices to charge from generic USB chargers like car adapters, AC adapters, etc. When connected to a PC, the device will know to charge but when connected to a standalone charger, there is no data transmission to say "I'm a Mac (or I'm a PC)" and so it will refuse to charge. Apple, of course, sells chargers that work fine, so what’s the deal?
Like with the line-out problem, this is also related to some pins being connected to resistors. Pinouts.ru has a list of what’s needed to make each device work (this problem was introduced with the iPod Video). I haven’t tried these myself so I can’t validate any of them, but that site generally has a good idea of what’s what. As you can see though, it’s not exactly the easiest task to make it work.
Fortunately, someone has done it for us. Boxwave has an adapter that will let you plug an iPod cable in one end and then whatever generic USB charger you want into the other end. Boxwave operates with device-specific accessory descriptions and doesn’t specify which other devices it works with, but as far as I know the adapter is universal for the latest generation of devices. In other words, though the link points to the iPod touch one, it’s the same adapter as if you browsed the site for iPhone 3G accessories or iPod nano. I use this accessory with a USB AC adapter, USB car adapter, and an external USB battery.
My personal tip is to pair the adapter with a shortened USB cable like the iStubz. This way, you’ll have a very useful little charging cable that you can use with any charger you want. I use a homemade shortened cable with a $4 USB AC adapter, a $2.50 USB car adapter, and a 3400mAh external battery, all of which charge my iPod touch perfectly. The biggest advantages to such a solution over the official Apple products are, of course, price and the fact that you can use them with other gadgets as well. The external battery, for instance, has been with me through many gadgets; buying a separate one just for my iPod touch would have been a waste of money.
Lastly, there is the issue that has caused a lot of people to get upset when upgrading their iPod or iPhone to the newest generation: removal of FireWire support. Not many people use FireWire for portable devices so it might not seem like a big deal, but its removal actually caused a lot of docks and accessories to stop working properly. Specifically, they would no longer charge the device.
FireWire operates at 12V while USB only uses 5V, which means they use separate pins for power on the iPod dock connector. As a result of the voltage difference, charging through FireWire is a lot faster than charging through USB. Many accessories such as docks and car chargers therefore used the FireWire power pins to provide power; when FireWire was removed, the accessories were basically shooting blanks in the power department.
One of the most popular docks with this problem is the Bose SoundDock, but the problem applies to many accessories that include charging. I was lucky that my Logitech Pure-Fi Anytime alarm clock dock already used USB, so when I upgraded to the second-generation touch my dock still worked.
The solution to this problem is an adapter that turns the 12V FireWire power into 5V USB power. There are many companies out there making these adapters, but my favorite is again Ridax. They have a small version that adds some bulk but is still the most low-profile solution I’ve seen; they also have a larger one that has a miniUSB port on the side so you can add charging to accessories that don’t charge in the first place. Ridax also has a replacement PCB for the aforementioned Bose SoundDock to get it to charge newer devices, but this solution is a bit more expensive and requires some technical knowledge to install.
Hopefully this will help those of you out there that have found your old accessories to be incompatible with your new device. It’s a pity that Apple introduces these things, especially since the iPod dock connector is thought of as a "what fits, works" solution. Finding what works and what doesn’t can also be hard since the absence of compatibility info on the newest model might just as well be that they haven’t updated the compatibility list (or that the accessory was produced before the new models were released) and doesn't necessarily mean it doesn’t work. So if in doubt, be sure to check the compatibility on the Internet before buying.
Andreas Ødegård is currently finishing the second year of a three-year bachelor's degree in Economics and Administration at Lillehammer University College in Norway. He loves gadgets of all sorts and has been writing for Anything But iPod since January 2008, as well as updating his own DIY blog.