Creating a Bluetooth iPod Classic
As a society, we are becoming increasingly dependent on our phones for everything. They act as our communication devices, TVs, and music players. All of this sounds good in principle, however, when we add on the constant pressures of social media algorithms and regular notifications phones can quickly become a burden.
I’ve always used my phone mainly for playing music. While there are huge problems with streaming services regarding paying artists, I truly believe that streaming is the best way to enjoy music. However, while streaming on my phone I am constantly distracted by social media, notifications and messages. I have been seeking for a while a dedicated music player that can replace my phone. There is one issue though, I don’t like wired earphones, they tangle, break and are a pain to use when walking. The solution: a Bluetooth iPod.
The first video that piqued my interest in this topic was an early video by DankPods. This was a rather sketchy solution to the problem, requiring the iPod to be opened each time you wanted to use it. He later improved on it with the help of a friend, creating a solution where the Bluetooth module could be powered by the internal battery of the iPod and could be turned off and on by an external switch. This was later turned into a full guide with a wiring diagram by Pendleton 115.
After finishing off a couple of previous projects. I decided to give this project a go, I aimed to flash mod an iPod, install a fresh, larger battery and connect up a Bluetooth module, all while keeping the original functionality of the iPod the same.
When my iPod arrived, I first started working on the flash mod and battery replacement. Most iPods come in poor condition due to their age, so I made sure to purchase a replacement back and front housing. To aim to try and increase the Bluetooth range, I got my friend to 3D print me a plastic iPod back as well to try out.
I decided to use a 5th-generation iPod for this project, this was for 2 reasons. This iPod has a better-sounding Wolfson DAC than other iPod models and is so much better to open and close than the 6th and 7th-generation iPods. These later iPods are notoriously hard to open and can easily break.
Flash modding the iPod is a simple procedure, the hard drive is replaced with a slimmer SD card replacement. I did have an issue when testing out the flash mod, I was presented with the dead hard drive sign. Thinking this was a problem with my flash mod, I un-attached and re-attached the adapter multiple times with no luck. It turned out to be a faulty SD card. I found using a Samsung EVO card instead of a SanDisk gave the best results in the flash mod. When synchronizing the iPod after flash modding it, you may find that a few restarts of the computer are needed between restoring and syncing the iPod, as the finder can hang.
In the 5th generation iPod, the battery is connected to the main board via a plastic connector. One word of caution, this piece of plastic is incredibly fragile and can easily break. I had to get a replacement iPod while flash modding since I broke and subsequently lost this piece of plastic.
Testing out the new battery was a simple task, simply swapping out the older 450mah battery with the newer 3000mah one. Since the iPod I used had a very scratched-up front panel I also replaced this with a custom purple front housing.
Next was the preparation and soldering of the Bluetooth module. Pendleton 115 used a TaoTronics Bluetooth receiver which I managed to find on eBay for £20, I could have used a cheaper Amazon knock-off but I wanted this project to last and be useable, so I opted to buy this more expensive one.
To prepare the module, we first need to strip the logic board from the housing, this can be done by prying off the plastic cover and then unscrewing the logic board.
Next, we have to strip off the components from the board, we start with removing the battery. This is not needed as we will power this board from the internal iPod battery. We also remove the micro USB charging port for the same reason.
The on/off switch was then desoldered as we will be connecting a separate switch. Finally, we pry off the headphone jack. This process was very delicate since if you pull on the headphone jack too much, the solder pads connected to it can be pulled off as well. I accidentally ended up destroying all the solder pads on my first attempt and had to order a replacement Bluetooth module. The key to removing this is to slowly chip away at the jack using a small set of pliers. Then when enough of it is removed, we can desolder the rest.
If done correctly, we should be left with a bare PCB that we can solder to.
The final job is to solder this PCB to the needed iPod components. First, the headphone jack of the Bluetooth module needed to be soldered to the iPod jack. This simulates the connection made if you were to plug in the 3.5mm connector of the Bluetooth module into a device. Pendleton 115 created a wiring diagram that can be used. However, if a different Bluetooth device is used then a small pin-out device seen below and a multimeter set to connectivity mode can be used to work out which pins of both jacks correspond to ground, right and left.
We can check that the connections made are solid by using this device, one end of the multimeter connects to the pin-out device and the other to the solder joint on the Bluetooth module. We should hear solid beeps from the multimeter from one solder joint for each output on the pin-out device.
Next, we connect up the power. The pins on the battery connectors on the Bluetooth board are soldered to the battery pins on the iPod. This was the trickiest soldering of this project. The pins on the iPod are very small and did not attach very well to the solder. The best solution was to turn up the heat on my soldering iron and tin the copper wires before soldering them to the battery pins.
Make sure that the wiring is correct here, as there is a specific ground and 5V pin to connect on the iPod and Bluetooth side.
Finally, we connected a switch to the switch pins on the Bluetooth board. The end goal here is to attach the switch to the area just under the hold switch so that when we push the hold switch down (not slide) we click this switch which turns the Bluetooth module on. This was a very simple connection to solder, simply connecting the pins from the switch to the small legs on the switch.
A simple test can be done to see if everything works, the Bluetooth module should turn on, connect to a device and successfully play music from the iPod.
The final stage was to place everything back into the iPod and close it up!
Originally, the plan was to use a plastic back to increase the resulting Bluetooth range of the iPod. However, on the 3D-printed back, there are no screw holes to attach to. Therefore, I had to result in hot glue. This made quite a mess and I had to use so much hot glue that the front panel would no longer close on the back.
Thinking of longevity here, I instead opted to use a metal back with proper screw holes. I snapped off the left piece of the hold switch so that it could be pressed down and subsequently click the switch for the Bluetooth module. The switch was held into place with hot glue. The placement of this switch is incredibly important, it should be placed as close to the hold switch as possible. I found it best to place a bit of hot glue and then push the switch as far as possible against the hold switch.
For all the components to fit well in the iPod, one additional step that we must take is to trim down the flash mod. There is enough space without doing this, but the Bluetooth module will sit on top of the flash mod and could cause issues in the future if it is dropped. Since this was a project I wanted to use in my day-to-day life I opted to trim down the adapter. There is no logic above the sd card, so I used a dremel to cut off the top. This was the first time I used a Dremel, but luckily everything went smoothly!
To secure all the new components to the iPod, I opted to use a combination of double-sided sticky tape and foam pads. Lastly, after giving everything one last test, the iPod can be closed up!
The only outstanding issue with this project is a problem with the charging circuit. Essentially, the charging of the battery in the iPod is problematic. The large 3000 mAh battery does not seem to properly charge and after leaving the battery to drain (in an attempt to calibrate it), the iPod is stuck in a low battery state. This is still an ongoing debug issue for me, probably requiring me to purchase a new iPod and move all the components to this.
Regardless of this issue, this project has been incredibly fun to do. Adding Bluetooth adds a piece of (somewhat) modern technology to the iPod and makes it much more convenient to use with today’s headphones. Simply flash modding an iPod is quite an easy project and so adding this additional Bluetooth module adds a nice challenge. I now have a dedicated music player that can work with modern Bluetooth devices and the purple colour scheme will turn heads!
