iPS 232: Andrew’s Audio Data-Transfer Adventure



    • Jaim Zuber
    • Andrew Madsen
    • Gui Rambo

    In today’s episode, the iPhreaks panel talk about Andrew’s client project that he’s been working on. To combat an issue, he has been using the audio port on the iPhone in order to transport data. With this, you don’t need any approval from Apple and the hardware is very simple. They go more in depth about how this process works and how iPhone updates affect it, such as the loss of the headphone jack.

    In particular, we dive pretty deep on: 

    • About the Project
    • How does it work?
    • Bell 202
    • Frequency Shift Keying
    • How does it work with iPhones without new headphone jacks?
    • What libraries are available?
    • JM FSK-25 Modem
    • Andrew wrote his own library as well
    • How do you get around transmission issues?
    • Erroring checking
    • What type of device is on the other side?
    • How do you structure your data?
    • What other apps can use this?
    • How is the audio with Bluetooth?
    • Tech support
    • Getting into the DSP weeds
    • Zero cross detector to determine frequency
    • Channel Coding
    • How can I learn about the Core Audio APIs?
    • Audio Queue Services
    • And much, much more!