Scientific Oregon WMR300 Temperature and Humidity Sensor THGN300

[mankan]

Trying to get a temperature and humidity sensor THGN300 working. It is connected to the outdoor unit for a Oregon Scientific WMR300 weather station. The rain and wind sensors connected to the outdoor unit is working fine. So I suspect its the actual sensor in the THGN300 that is faulty and to verify this I would need help in identifying the sensor IC first. The IC is marked FEO 11 and is mounted on a small adapter PCB.

Anyone knows what it is?

[ebastler]

This one seems to have the same (unusual) package: Sensirion SHT11. Discontinued unfortunately, but maybe you can find some leftover stock somewhere, or the datasheet helps to find something electrically compatible?

Catalog page: https://il.rsdelivers.com/product/sensirion/sht11/sensirion-sht11-temperature-humidity-sensor-40-c-c/7865551
Datasheet: https://docs.rs-online.com/58dc/0900766b81389d82.pdf

Edit: Sensirion recommends the SHT40 as a successor product. I have not checked whether it is directly compatible (electrically, the package is obviously different).

https://sensirion.com/products/catalog/SHT11/
https://sensirion.com/products/catalog/SHT40/

[mankan]

After removing the weather protective rubber I could measure the PCB and it all fits with the SHT11 datasheet. However I found that 3 of 4 PCB traces had corroded severely and VDD trace was broken. Now that I've repaired the traces with some wires, the next step is to verify the sensors function with an MCU.

SHT11 uses a proprietary 2 line serial protocol and SHT40 has I2C so that would require an MCU with some translation SW to get it backwards compatible with the outdoor unit. However it costs less than 3€ when one SHT11 including shipping would set me back €85.

[mankan]

I found SparkFun SHT15 modules for €40 which I bought and used as donor to the board. Works fine with Arduino at least. Will be a few weeks before testing in the weather station can be done.

[mankan]

Forgot to report back. The temp and humidity sensors are now working fine in the weather station.

[rocchino.palcera]

Hi, i have the same problem. Can You share me the solution adopted? What modules i have to buy? thanks in advance.