Firmware Development
From board bring-up to production, in C and Python.
DetailIndependent embedded engineering practice
Low-level engineeringfor embedded systems.
Firmware development, reverse engineering, and networking on constrained hardware. I work at the layer below the application: bring-up, drivers, boot chains, protocols, and the security of all four.
Demux Labs is one engineer. The person you scope the work with is the person who writes the code.
CC++PythonARM Cortex-MBare metalFreeRTOSLinuxJTAG/SWDCANUSBSecure bootTLS
What I do
Four kinds of work, one engineer.
Most projects need two of these. A few need all four. They are listed separately because they are priced and scoped separately, and there are three more on the services page.
Looking for a one-stop shop?
Concept to production, or any single stage of it.
Most engagements are one or two of these. Some are all seven. The sequence below is how an embedded product usually gets built; you can join it wherever you currently are.
01
Concept Development
Turning an idea into something an engineer can cost. What the device must do, what it must never do, and which constraints are real.
02
Architectural Design
Silicon selection, system topology, security model, and the interfaces between subsystems, all written down.
03
PoC Development
The fastest honest answer to 'does this work at all'. Development boards, throwaway firmware, and one real end-to-end path.
04
MVP Firmware Development
Firmware on your own hardware, doing the actual job. Good enough to demo, pilot, and put in front of users.
05
In-House Tools & Processes
QA rigs, debug tooling, key generation, provisioning and association flows, so your team can run the product without me.
06
Production-Ready Firmware
Secure boot, key storage, updates with rollback, certified module integration, and the failure paths nobody enjoys writing.
07
After-Market Integrations
Extending hardware that is already in the field (new protocols, new back ends, new platforms) without bricking the installed base.
Working knowledge
Need me to hit the ground running?
Languages
- C
- C++
- Python
Targets
- ARM Cortex-M
- AVR & MSP430
- Espressif / ESP32
- Raspberry Pi
Runtimes
- Bare metal
- FreeRTOS
- Linux
- Arduino
Buses & interfaces
- I²C, SPI, UART
- CAN & RS-485
- USB
- JTAG / SWD
- Modbus
- HTTP
Networking
- TCP/IP on constrained stacks
- TLS / mTLS
- BLE, Wi-Fi, 802.15.4
- MQTT & proprietary protocols
Reverse engineering
- IDA
- Firmware extraction
- Logic & protocol analysis
Security
- Secure boot & chain of trust
- Secure elements, TPM
- Key generation & provisioning
- Fault & side-channel awareness
Engineering
- Hardware-in-the-loop CI
- Static analysis
- Production test rigs
- Release & signing automation
This is a baseline, not a ceiling. Whatever hardware platform, runtime, protocol, or toolset a project actually needs, I will pick it up, just as everything above got picked up in the first place. What stays constant is fluency across the stack, from register-level firmware to the abstractions built on top of it.
Writing
Notes from the bench.
-
Integrating Systems Into Your Smart Home Using Arduino Nano Matter
Integrating an old Mitsubishi Electric HVAC system into a Matter smart home using an Arduino Nano Matter.
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Practical Introduction to BLE GATT Reverse Engineering: Hacking the Domyos EL500
A practical introduction to reverse engineering Bluetooth GATT devices, using a Domyos EL500 elliptical trainer as an example by leeching notifications, spoofing the device with an ESP32, and building a man in the middle to log its protocol.
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Learning to Decapsulate Integrated Circuits Using Acid Deposition
A trial and error account of learning to decapsulate integrated circuits at home using nitric acid deposition, an acetone syringe, and an ultrasonic cleaner, including safety precautions and microscope photos of exposed silicon dies.
Tell me what you are building or what you have inherited.
A short description of the hardware and its current stage is enough to start. I will come back with an approach, availability, and a rate, or an honest no.