Wired FTDI USB-serial support for iOS apps?

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Level 1

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Wired FTDI USB-serial support for iOS apps?

Can an iOS app access a generic FTDI USB-serial device? (Works on Android, not on iPhone).

Hello,

I am developing a cross-platform mobile app that communicates with an external accessory over a serial (UART) link.

HARDWARE : The accessory is an optical reading probe that connects to the phone via USB. Inside the cable there is a standard FTDI USB-to-serial chip (similar to common FTDI/CP210x USB-serial adapters).

WHAT WORKS On Android, our app:

Detects the USB device
Opens the serial port
Reads and writes raw bytes successfully

This wired FTDI path is fully implemented and working.

WHAT DOES NOT WORK On iPhone, using the same wired FTDI USB accessory:

We connect via Lightning or USB-C adapter
The app never sees the FTDI device
We cannot find a public iOS API to open a generic USB-serial port

MY QUESTION :

Is there any supported way for a third-party iOS app to communicate with a generic FTDI USB-serial device over a wired USB connection?

Specifically, am I missing:

A public Apple framework for USB serial?
An Info.plist key or entitlement?
A system driver on iOS similar to macOS AppleUSBFTDI (TN2315)?

Or is wired USB-serial on iPhone only possible with MFi-certified accessories (External Accessory framework) or another transport such as Bluetooth LE?

WHAT I HAVE ALREADY CHECKED

External Accessory: seems to require MFi hardware and a registered protocol string. Our FTDI probe is not MFi.
TN2315 (AppleUSBFTDI): appears to be macOS only, not iOS.
Physical USB connection: cable fits, but no serial API is exposed to the app.

ENVIRONMENT

Platform: iOS (iPhone)
Language: C# / .NET-iOS
Need: transparent byte-level serial read/write

SUMMARY:

Android USB-serial works with our FTDI wired accessory. iOS does not.

Am I missing something on iOS, or is generic FTDI USB-serial simply not supported for third-party iPhone apps?

Thank you for any guidance.

MacBook Pro 16″, macOS 26.5

Posted on Jun 16, 2026 5:11 AM

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Answer 1

LotusPilot

Level 10

321,470 points

Aug 17, 2026 1:37 AM in response to abdulwaseycs

While not necessarily doubting your knowledge of hardware and associated interfaces, you may be missing a key difference between Android and Apple devices...

Unlike Apple devices that feature a USB-C port, Apple devices that employ a Lightning port do not have the necessary hardware to act as USB Controller / Root Hub. However, these hardware components can be added using Lightning to USB3 Camera Adapter:

Lightning to USB 3 Camera Adapter

https://store.apple.com/uk/xc/product/MK0W2ZM/A

In more detail, you cannot directly connect USB accessories to a Lightning equipped iPad/iPhone by way of a cable connection alone - and a simple plug-adapter won’t work. Non USB-C accessories require connection to host devices that employ a USB Controller / USB Root Hub.

The required USB hardware components can be added through connection of the Apple Lightning to USB3 Camera Adapter. This adapter contains an Interface converter, USB 3.0 Controller and USB Root Hub - presenting a USB 3.0 Type-A connection to which you may connect many (but not all) categories of USB devices. USB Device support by iPad is generally limited to Mass Storage devices, basic HID devices (such as wired Keyboard and basic Mouse) and some audio - unless you provide the necessary device driver software by way of an installable App. Presumably, this will be the App that you are attempting to develop for Apple devices.

For iPad models that incorporate a USB-C port, you have greater flexibility in the devices that can be directly connect to the iPad - as the necessary USB Controller is already incorporated in the iPad/iPhone hardware; no additional hardware components or interface conversion is required.

As for your App development, the Apple Developer Forum may be a better target for code enquiries:

Apple Developer Forums

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