IoT device and hardware development
I design and build devices that measure, control or connect existing equipment to the network. From a prototype on the desk through firmware to a web interface and dashboard, with security from the start.
What I can build
- Sensor nodes for temperature, humidity, light and other quantities
- Control of pumps, fans, lights and relays with safeguards
- Putting older ethernet-only equipment on WiFi
- Measuring instruments with a display and controls
- A web interface on the device itself and a cloud dashboard
Technology
I work with ESP32 microcontrollers and the ESP-IDF framework, writing firmware in C and C++. Data travels over HTTPS or MQTT; I build the backend in Python (FastAPI) on PostgreSQL and TimescaleDB and the frontend in React. Schematics are drawn in KiCad.
Device security
- Signed firmware updates with rollback to the previous version
- Encrypted communication with certificate verification
- No passwords or tokens in the code, each unit has its own
- Safeguards for actuators, so the device cannot cause damage even during an outage
How we work together
We start with what the device should measure or control and where it will live. I build a working prototype on a development board, we test it in real use, and if needed I design a custom PCB.
