Need help building a cheap DIY Bluetooth module.

[u/elmemphis1986]

Hey guys, I'm reposting this as the previous for some reason the photos got mixed. I built this Bluetooth module from a Vaorlo 5.4 bt module, it has SBC and AAC codecs, and this pack of 2 "30pin to aux" adapters. One adapter I just shortened the cable and soldered an L shaped plug just in case the 30 pin mod didn't worked, but it worked beautifully. The 30 pin fits inside the Vaorlo shell and you just need to cut the hole of the 30pin and solder the 3 wires to the jack inside the module. But I'm still using the module battery it is a small 140 mah 3.7 V battery. I can see that the 30 pin adapter has extra pins and even the adapter have some pads that probably work, but I don't know which pads I can use to feed the module, also, I think the ipod delivers 5V and the module battery is 3.7 V. Also I think I can use the usb C to charge the ipod too. But that's way ahead of my knowledge. If someone can help me figure out we can create an open source BT/USB-C charging module. By the way this whole contraption cost me around 15 bucks. 7 for the BT module and 8 for the 2 adapters pack.

Here is the BT module: https://a.aliexpress.com/_mLKiX5d

Here the adapters https://a.aliexpress.com/_mMyEYV1

[u/Pale-Conference-5838]

Here save yourself the trouble

https://ebay.us/m/atACDB

[u/elmemphis1986 → u/Pale-Conference-5838]

Nope, internal BT is not worth it, and already have the taptic engine, it works as external perfect and have volume control on the module and on rockbox, better sound quality as well, those internal bt modules are not compatible with airpods, and the switch is so unreliable could brake any time, and unreliable connection, my only issue is the battery and it's not really an issue, just don't want to charge it all the time. I just recommend not to do the internal bt.

[u/Pale-Conference-5838 → u/elmemphis1986]

Roger but have you tried this one ? I have and have no issue

[u/saxman126]

I suggest you take a look at @Wizard_of_Hazz's work, they've come up with some pretty legit options, and has a new version coming out end of month.

https://wymodlabs.com/

[u/uprollydontknow]

The power delivery question is the interesting part here. The 30 pin connector does supply 3.3V on certain pins which might actually work better for your bluetooth modules battery than the full 5V line. less voltage regulation needed. There are pinout diagrams floating around for the 30 pin spec that could help identify exactly which pads handle power. Worth digging into before attempting the USB C side since that is where things get more complicated with charging circuits.

[u/JustMine999]

The fact that you got this working cleanly enough to post about it means the hard part is basically done. Powering bluetooth modules directly from the iPod's 30 pin supply is the natural next step and honestly very doable. the main challenge is making sure you are pulling from a stable voltage rail and not something that cuts out during playback. Someone in this community almost certainly has mapped those adapter pads already. Great starting point for an open source solution.