Review on Comimark Temperature Humidity GY 213V HTU21D Replace by David Lusk

I connected 1 DHT22 (Temperature/Humidity), 2 18B20 (Temperature) and 1 HTU21D to ESP-WROOM-32 to measure for home use. Assistant. I'm trying to find an inexpensive sensor that offers decent accuracy for regular home monitoring. While absolute accuracy is not critical, I don't want to see measurements from devices in the same room with significant differences unless justified (near a vent, window, etc.). At first glance, this sensor appears to have leveled off quickly. a temperature that matches (within 0.5°C) my other sensors connected to the same ESP32 board, all very close together so I can compare the readings. However, within about an hour, the delta increased to 1 °C from the other sensors. The humidity reading is more than 5% lower than the DHT22 and from all other sensors in the house it seems too low. It may take some time to stabilize, so the jury hasn't been rendered yet. After an hour, it was still at least 5% different from the other readings I compared it to. Bottom line, the HTU21D reports slightly higher temperatures and lower humidity readings than my other sensors. The HTU21D requires I2C, which you must enable on your ESP board. The chip used on this board has a fixed I2C address of 0x40, so you can't connect more than one of them directly to the same I2C bus on the same board. I believe there is a way to get around this using a multiplexer, but I haven't looked into it yet. The bus requires pull-up resistors which you can either add or enable those found on this board. If you look closely, there are 3 narrow areas under the chip in close proximity. You need to connect (solder) the 3 pads together to activate the resistors. I would suggest using a very small tip and a temperature controlled iron to avoid damaging the board/sensor. The sensor on this board has no filter and can therefore become dirty, which can affect accuracy. Other brands offer a version with a PTFE filter (white square over the hole), but they are much more expensive. The two screw holes are approximately 3mm in diameter. Although this is the usual size I find it too big and doesn't leave much room for the screw heads. The pin header that comes with this board is straight, but I soldered the pins at a 90 degree angle as I prefer to use them. with breadboards or even when using DuPont jumpers in my prototyping. I'll have to do more research to see which sensor is actually giving accurate readings, but considering all the others are close, I'm inclined to think the HTU21D isn't as accurate (at least probably less than the others I've used have). ).