Android Developer (Native, USB & Audio) for Proof-of-Concept App

We are looking for an experienced Native Android Developer to build a very small proof-of-concept app that communicates with a custom hardware adapter via USB-C. The PoC scope is intentionally minimal — the app only needs to handle a few control commands and bidirectional audio streaming. About the hardware (important for understanding only) The hardware is a custom USB device based on an STM32 microcontroller. The MCU exposes: - a USB CDC (serial-like) interface for control commands - and a USB-based audio stream (PCM or USB Audio Class) mportant note: We cannot provide external test hardware. All testing with the physical device will be performed on-site by our hardware engineer. You will implement based on documentation and receive quick feedback after each iteration. Project Scope (Proof of Concept) Your tasks - USB Communication - Implement Android USB Host connection - Automatically detect our USB device (VID/PID provided) - Open communication channel (CDC or bulk endpoint) Control Commands Implement a small protocol to send/receive simple commands, such as: - Trigger TX mode (push-to-talk) - Exit TX mode - Request basic status information Audio Transfer - Send microphone audio → USB → hardware - Receive audio from USB → play on device speaker - Basic buffer handling (low-latency is not required for PoC) Minimal UI - One large PTT button - Simple connection indicator - status indicator for RX/TX No design work required — functionality is the only goal. Requirements - Strong experience with Native Android development (Kotlin or Java) Practical experience with: - Android USB Host API - USB CDC or raw USB bulk transfer - AudioRecord / AudioTrack - PCM audio handling Ability to work with hardware documentation instead of physical access Clean code, clear structure, and excellent communication Nice(st) to Have - Experience with embedded devices or microcontrollers - Experience with USB Audio Class - Understanding of low-level protocols Collaboration Setup - You will receive complete hardware documentation, USB interface specification, and protocol description. - You develop remotely. - All tests with the physical device are performed by our hardware engineer on our side. - We provide fast feedback cycles and video demos of test results when needed. Apply tot his job