Embedded · Rust · ESP32-S3
entry: embedded systems for a findable, multi-credential key fob
A personal hardware and firmware project exploring the path from a physical product idea to a dependable device.
Challenge
Turning a product idea — a findable key fob carrying multiple credentials — into a device you can trust means bringing up unfamiliar hardware interfaces without letting the project collapse into a one-off device script.
Contribution
Built a bench platform in Rust on an ESP32-S3, with secure-element integration, NFC communication, and Bluetooth Low Energy experiments. Firmware, hardware, and protocol work are organized as independently testable milestones.
Outcome
A bench platform for testing the key fob's communication and credential-storage components together.
Hardware and validation
An asynchronous driver integrates the OPTIGA Trust M secure element, a dedicated chip for protected storage and cryptographic operations. NFC-V communication was checked by reading the same tag blocks over radio and I²C independently, then comparing the results.
Ownership of pins, buses, and chip selects is tracked in the type system. Two drivers claiming the same line become a compile error, making the electrical connections part of the software contract.