About SensorRig
I build and run my own home data-acquisition hardware — and this site is where I write down what actually worked, what burned out, and what the datasheet failed to mention.
Everything published here is measured on equipment I own and operate continuously:
- DS18B20 1-Wire temperature probes on long cable runs
- DHT11 humidity sensors (and their well-earned reputation)
- ESP32-C3 remote nodes linked back over HC-12 433 MHz serial radio
- CT clamps + ADS1115 for whole-house energy monitoring
- A Raspberry Pi 5 collector running asyncio → SQLite (WAL) → FastAPI → Chart.js
- A legacy RRDtool system still running in parallel, because you don’t switch off a working monitor until the replacement has proven itself
No stock photos of server rooms. No copy-pasted vendor tutorials. If a wiring diagram appears here, it’s because I wired it.
Why the parallel-run obsession
Monitoring you can’t trust is worse than no monitoring. Every migration written up on this site runs old and new side by side until the numbers agree. That’s slower, and it’s the only honest way to do it.
Related reading
- How to Spot a Fake DS18B20 Temperature Sensor on a Raspberry Pi
Spot a fake DS18B20 on a Raspberry Pi: family-code check, sysfs CRC test, and ice/boil calibration against the datasheet. 3 of 7 probes in one batch were counterfeits, drifting 1.5–3.5 °C.
- SQLite Rollups and Retention: Stop Your Sensor DB From Eating the SD Card
How rollup tables and a retention policy keep a Raspberry Pi sensor SQLite database from growing unbounded — and why SD-card wear is rarely the real problem.
- CT Clamp Burden Resistor Calibration for ADS1115: Avoiding Voltage Drift in Home Sensor Projects
CT clamp burden resistor calibration for ADS1115 on Raspberry Pi: pick the external burden, stabilise with a decoupling cap, and apply the DC-bias correction that separates a stable watt reading from drift — with the 51 Ω + 10 µF combination I actually measured.