The SHT-30 probe with its mesh cap unscrewed: the sensing element inside
Sensor
SHT-30 weatherproof probe
A research-grade temperature and humidity sensor in a weatherproof mesh tube on a 1 meter cable. Wires straight to an ESP32: four wires.
This is the wired path: no Bluetooth, no batteries in the cold space, just a probe on a cable reporting every time the board asks. Accuracy is a step up from the hobby pucks: half a degree C and 2 percent humidity.
Specs.
| Measures | Temperature and relative humidity, both from the one probe |
|---|---|
| Temperature accuracy | ±0.5 °C typical |
| Humidity accuracy | ±2 % RH typical |
| Interface | I2C (address 0x44), pullups built into the cable; four wires: power, ground, clock, data |
| Cable | 1 meter, weatherproof mesh-protected tip (breathes air, not for submersion) |
| Power | 3 to 5 V DC from the board; no batteries |
How to pick a good one.
- Adafruit part 4099 is the reference: mesh-protected SHT-30 with pullups already on the cable.
- Four wires: power, ground, clock, data. Any ESP32 board in this store reads it over I2C.
- The mesh tip breathes, so it reads humidity honestly; do not submerge it. For liquids, use the DS18B20 instead.