SEN0483 - RS485 Wind Speed Transmitter - over reading speed
Stuart.Hi 2025-09-26 17:55:55 368 Views9 Replies Hi,
I have an RS485 wind speed trandmitter connected to DFR0845: Active Isolated RS485 to UART Signal Adapter Module which is connected to an ESP32. I understand the maximum speed is 32.4 m/s (117 km/h) and that the raw value from the sensor needs to be multipled by 3.6 or 0.036 to convert to either m/s or km/h. I find that I need to multiply by 0.7 or 0.007 approximately to get an accurate figure (based on comparison to the local meteorological service). This means the speed is effectively limited to about 6.3 m/s or 22.8 km/h. Is there a way to reset or adjust the calibration of the sensor to give an accurate reading? I am comfortable issuing modbus commands (I have already changed the slave address of this unit). I am using ESPhome with their standard modbus library for communication.
Many thanks,
Stuart
Hi - I just wanted to let you know that I have solved my issue. I had SEN0482 and SEN0483 configured and I mixed up my modbus addresses. The data extracted above reflects the wind direction sensor not the wind speed sensor. Thank you for your time.
Stuart.Hi Here is an example of the data at each of the only two registers on the wind speed sensor. I have two units that are doing exactly the same thing and are not operating in accordance with your published specifications. Using the formula on the wiki page Reg 0 gives speeds in the thousands of km/h and Reg 1 gives speeds up to 5 km/h. Can you please advise a resolution? Are my products defective?
user@raspberry-pi:~/modbus/bin $ ./python3 /mnt/media/windtest.py
Wind Speed Reg0: 2386, Reg1: 11
Wind Speed Reg0: 2530, Reg1: 11
Wind Speed Reg0: 3183, Reg1: 14
Wind Speed Reg0: 2098, Reg1: 9
Wind Speed Reg0: 2247, Reg1: 10
Wind Speed Reg0: 2427, Reg1: 11
Wind Speed Reg0: 2730, Reg1: 12
Wind Speed Reg0: 2442, Reg1: 11
Wind Speed Reg0: 2288, Reg1: 10
Wind Speed Reg0: 1959, Reg1: 9
Wind Speed Reg0: 2545, Reg1: 11
Wind Speed Reg0: 2160, Reg1: 10
Wind Speed Reg0: 2427, Reg1: 11
Wind Speed Reg0: 2607, Reg1: 12
Wind Speed Reg0: 2391, Reg1: 11
Stuart.Hi I have been looking at the wiki and it indicates that the parameters from the sensor should be 0 to 324, which I presume means that each increment is 0.1 m/s. My sensor is reporting 0 to 3600 (approximately) which is not consistent with the documentation. Can you please investigate and advise of a resolution?
Stuart.Hi I have also asked this question on one of the local forums: https://forum.core-electronics.com.au/t/sen0483-rs485-wind-speed-transmitter-troubleshooting/23370
Stuart.Hi I can't edit my initial post. The figure to multiply the sensor output to obtain km/h is actually 0.36 which means that the sensor is an output well beyond the range for the unit (approximately 1000 km/h when the speed should be 20 km/h).
Stuart.Hi Find the exact model of your wind sensor (make, part number). The RS485-to-UART adapter (DFR0845) is just a signal converter and does not perform calibration.
ahsrab.rifat It is SEN0483. There is no information on the unit itself. This is the item I purchased https://au.mouser.com/ProductDetail/DFRobot/SEN0483?qs=pBJMDPsKWf1jLg3Zk5A%2FBQ%3D%3D&countryCode=AU¤cyCode=AUD
If it assists I purchased two wind sensors and they behave the same way in terms of their output.
The retailer has confirmed today that the model I purchased is SEN0483 referred to above.
