ESP32 Bluetooth Handsfree Gateway & WebSocket Audio Monitoring System

We are seeking an experienced embedded systems developer to build custom firmware for an ESP32. The primary objectives are to implement a Bluetooth Hands-Free Profile (HFP) using the BlueKitchen/btstack library and to develop a WebSocket server on the ESP32. This device will act as a gateway, enabling real-time control and audio communication between a PC and an Android device. The ultimate goal is to create an audio monitoring system that can send and receive audio between these devices over a local WiFi network on PC. So we can monitor calls and send quick calls from CRM to android.

Note: ESP32 board we are using is ESP-WROOM-32

Project Scope and Objectives:

Bluetooth Hands-Free Profile Implementation:
Integrate the BlueKitchen/btstack library to configure the ESP32 as a Bluetooth Hands-Free device.
Customize and extend the default commands provided by btstack to allow complete control over call management functions (e.g., send call, answer, end, mute, volume control).
Ensure reliable and low-latency communication with paired Android devices for call control.

WebSocket Server Integration:
Develop a WebSocket server on the ESP32 that listens for control signals from a PC over a local WiFi network.
Implement a protocol for receiving, sending, parsing, and executing commands to control the ESP32’s Bluetooth functionalities.
Ensure that the ESP32 can respond in real time to commands issued from a Python-based controller running on the PC.

Real-Time Audio Streaming:
Enable the ESP32 to send and receive audio data in real time.
Establish a pathway where audio can be streamed directly from the PC to the Android device (and vice versa) via the ESP32.
Ensure synchronization and minimal latency in the audio transmission, allowing for effective audio monitoring and control.

Network Connectivity and Security:
Connect the ESP32 to a local network via WiFi.
Provide mechanisms to retrieve the device’s IP address for connection from the PC.
Implement necessary security measures for WebSocket communications to prevent unauthorized access.

Integration with PC Control Application:
Design the system with the understanding that a Python-based application on the PC will handle WebSocket command transmissions.
Provide clear API endpoints and documentation for command structures and responses.
Allow for future scalability and modifications based on evolving requirements.
Allow realtime audio stream.

Deliverables:

Firmware Source Code:
Well-documented ESP32 code integrating BlueKitchen/btstack for Bluetooth HFP.
Custom command set implementation for call control and audio handling.
Embedded WebSocket server code handling real-time control and audio data streaming.

PC Integration Documentation:
API documentation detailing the WebSocket command structures, endpoints, and response formats.
Setup and usage instructions for the Python-based control script.

Testing & Validation:
Comprehensive test cases and logs demonstrating reliable Bluetooth communication, command execution, and audio streaming between ESP32, PC, and Android devices.
Troubleshooting guidelines and recommendations for further enhancements.

Deployment Guide:
Step-by-step instructions for flashing the firmware onto the ESP32.
Configuration guidelines for connecting the ESP32 to a local network and pairing with Android devices.

Required Skills and Expertise:
Strong experience with ESP32 development and embedded C/C++ programming.
Proven expertise with the BlueKitchen/btstack library and Bluetooth HFP integration.
Experience developing and debugging WebSocket servers on embedded systems.
Familiarity with real-time audio processing and streaming.
Proficiency in Python for PC-side integration and command control.
Understanding of WiFi networking and security best practices in embedded systems.