Embedded Electronics Engineer Needed – Custom Automotive Volume Knob Controller
Publicada el 2026-08-02
Descripción de la oferta
I am looking for an experienced embedded electronics engineer to design a custom hardware and firmware solution that adds a physical rotary volume knob to an aftermarket car stereo. The goal is to create a compact PCB that interfaces with the head unit's steering wheel control (SWC) input and translates rotary knob movement into volume up/down commands. The finished product should provide a smooth, factory-quality user experience with minimal latency and reliable operation in an automotive environment. This is a custom automotive electronics project. I am looking for someone who can design both the hardware and firmware from scratch. Project Scope The engineer will be responsible for designing, developing, testing, and documenting the complete system. This includes: Electronic schematic PCB layout Firmware development Prototype testing Bill of Materials (BOM) Production-ready design files Functional Requirements The finished controller should: Interface with a Kenwood DMX958XR head unit through the Steering Wheel Control (SWC) input. Accept input from a rotary encoder or equivalent high-quality rotary control. Detect clockwise and counterclockwise rotation. Increase and decrease volume smoothly. Support continuous scrolling while the knob is rotated. Have adjustable rotation sensitivity and acceleration. Feel responsive with virtually no noticeable delay. Power from a standard automotive 5V supply or USB-C. Be compact enough to mount behind a dashboard panel. Preferred Design Approach The implementation method is left to the engineer; however, possible approaches include: Microcontroller-based design Digital potentiometer / digitally controlled resistor network Resistance ladder simulation Steering Wheel Control protocol emulation Analog or digital signal conditioning as required Possible microcontrollers include (or equivalent): ESP32 STM32 RP2040 CH32 ATmega The engineer should recommend the most appropriate architecture. Hardware Requirements The PCB should include, where appropriate: Rotary encoder interface Microcontroller SWC output interface Power regulation ESD protection Reverse polarity protection Automotive noise filtering Programming interface Status LED (optional) Firmware update capability (USB or programming header) The board should be automotive-grade where practical. Firmware Requirements Firmware should include: Rotary encoder decoding Debouncing Adjustable acceleration Smooth volume changes Error handling Stable startup Low latency response Expandable architecture for future features Source code must be included. Future Expandability The design should allow room for future additions such as: Mute button Track forward/back Play/Pause Source selection Voice assistant activation Multiple programmable buttons OLED or LCD status display RGB status lighting Bluetooth configuration Firmware updates CAN/LIN integration (optional) Deliverables Complete schematic PCB files (KiCad preferred) Gerber files Bill of Materials Assembly drawings Fully documented firmware Programming instructions Prototype build recommendations Testing procedure Experience Required Please apply only if you have experience with: Embedded systems PCB design Automotive electronics Microcontroller firmware Rotary encoder implementation Digital signal processing Reverse engineering communication protocols (if required) Low-latency embedded applications Experience with aftermarket automotive audio systems is a strong plus. What I'm Looking For I'm looking for someone who enjoys designing high-quality embedded hardware and can recommend the best technical solution rather than simply following a fixed design. The finished controller should be reliable, responsive, compact, and engineered to a professional standard suitable for long-term use in a custom automotive installation.
Skills
Fuente original: freelancer