DONGKERTemperature Humidity Sensor Module, XY-MD02 Temperature Humidity Transmitter Module Transducer SHT20 Sensor Module

With a quick Google search you can find the product manual. There’s not much to it, but there’s not much to this device. You just power it up and communicate with it RS-485 Modbus RTU.

I bought 3 of these and they are all way off for both temp and humidity. The best one is 10%RH off, and a few degrees. I adjusted the calibration registers, can read back that they were properly written to, but the values it outputs do not change at all. Power cycled them, etc, no change. I will play around with them a little more, but will likely be returning them for a refund.As another customer said, they are well made, its just a shame they aren't accurate and don't calibrate.Upon further inspection, this product doesn't even use the sensor listed on the product page (SHT20), it has a SHTC3 sensor...

I bought this sensor for a home automation project based on an Allen Bradley Micro820 PLC. The sensor seams to work really well once you get it configured. The available documentation is a nightmare and i dont know if the fault mainly lies with this sensor or with Connected Components Workbench but after many hours of crazy frustration i found the address and speed settings at 0x3 286 not at 0x3 101 as stated in the docs. Then it turned out that the temps and humidity were interpreted strait to c and %, no hex conversion required, which was a bonus at that point. I get nice high resolution trending on the humidity but the temp is not nearly as good.Once i set the new address and comm speed i had to power cycle the unit for it to take effect

Want to like this device. Well put together and modbus works as advertised. Unfortunately, looks like it is uncalibrated. Reading 25% humidity when actually 43%. Reading 98 F (37 C) when actually 73. Purchased 2 of these and neither tracked reality or each other. They provide a calibration register that allows +/- 10 C and +/- 10 %humidity adjustments, but that is insufficient to correct the error and with this much error, don't trust the device to provide calibratable readings.