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Hydreon RG-15 Solid State Rain Sensor~

This feature is not included in precompiled binaries

You must compile your build. Add the following to user_config_override.h:

#ifndef USE_HRG15
#define USE_HRG15    // Add support for Hydreon RG-15 Solid State Rain sensor (+1k5 code)

The Hydreon RG-15 Solid State Tipping Bucket is a rainfall measuring device intended to replace conventional tipping buckets.

The RG-15 uses beams of infrared light within a plastic lens about the size of a tennis ball. The round surface of the lens discourages collection of debris, and the RG-15 has no moving parts to stick, and no water-pathways to clog. The device features an open-collector output that emulates a conventional tipping bucket, as well as serial communications that provide more detailed data and allow for configuration of the device.

Find out more on the manufacturer's website.



HRG15 ESP8266
VCC (8) 3.3V
RS232 Out (4) GPIOx
RS232 In (5) GPIOy

Tasmota Settings~

In the Configuration -> Configure Module page assign:

  • GPIOx to HRG15 Rx
  • GPIOy to HRG15 Tx


Sensor90 can be used to configure the rain sensor

Tasmota Display~

After a reboot the driver will detect the sensor and show the sensor data. An example is given below:

Item Value
RG-15 Active 0.01 mm
RG-15 Event 0.13 mm
RG-15 Total 26.8 mm
RG-15 FlowRate 0.32 mm.h

This data is also part of the tele/%topic%/SENSOR payload:

    "Time": "2021-08-25T17:15:45",
    "RG-15": {
        "Active": 0.01,
        "Event": 0.13,
        "Total": 26.80,
        "FlowRate": 0.32
    "TempUnit": "C"


The sensor data is made available over MQTT as per the configured TelePeriod. Additionally, instant telemetry messages are sent during active rainfall events. The sensor will report additional accumulation every 5-60 seconds. The driver resets the Active and FlowRate values to 0 if no additional accumuatlion is detected after 60 seconds.

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