Mysensors moisture sensor erring out in HA

I am attempting to present a mysensors moisture sensor to HA (new python venv install). I am using the following sketch with the below resulting logs. I have changed the mysensor library version several times and the sketch and current sensor state appear to be passed to HA but I am not finding a resolution to this issue.

Wifi-moisture-sensor sketch

 * The MySensors Arduino library handles the wireless radio link and protocol
 * between your home built sensors/actuators and HA controller of choice.
 * The sensors forms a self healing radio network with optional repeaters. Each
 * repeater and gateway builds a routing tables in EEPROM which keeps track of the
 * network topology allowing messages to be routed to nodes.
 * Created by Henrik Ekblad <[email protected]>
 * Copyright (C) 2013-2019 Sensnology AB
 * Full contributor list:
 * Documentation:
 * Support Forum:
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 * Arduino soil moisture based on gypsum sensor/resistive sensor to avoid electric catalyse in soil
 *  Required to interface the sensor: 2 * 4.7kOhm + 2 * 1N4148
 * Gypsum sensor and calibration:
 *  DIY: See
 *  Built: Davis / Watermark 200SS
 *    cb (centibar)
 *      0-10 Saturated Soil. Occurs for a day or two after irrigation
 *      10-20 Soil is adequately wet (except coarse sands which are drying out at this range)
 *      30-60 Usual range to irrigate or water (except heavy clay soils).
 *      60-100 Usual range to irrigate heavy clay soils
 *      100-200 Soil is becoming dangerously dry for maximum production. Proceed with caution.
 * Connection:
 * D6, D7: alternative powering to avoid sensor degradation
 * A0, A1: alternative resistance measuring
 *  Based on:
 *  "Vinduino" portable soil moisture sensor code V3.00
 *   Date December 31, 2012
 *   Reinier van der Lee and Theodore Kaskalis
 * Contributor: epierre

// Copyright (C) 2015, Reinier van der Lee

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// GNU General Public License for more details.

// Enable debug prints to serial monitor
#define MY_DEBUG

// Enable and select radio type attached
#define MY_RADIO_RF24
//#define MY_RADIO_NRF5_ESB
//#define MY_RADIO_RFM69
//#define MY_RADIO_RFM95

#include <math.h>       // Conversion equation from resistance to %
#include <MySensors.h>

// Setting up format for reading 3 soil sensors
#define NUM_READS (int)10   // Number of sensor reads for filtering
#define CHILD_ID 0

MyMessage msg(CHILD_ID, V_LEVEL);
uint32_t SLEEP_TIME = 30000; // Sleep time between reads (in milliseconds)

long buffer[NUM_READS];
int idx;

/// @brief Structure to be used in percentage and resistance values matrix to be filtered (have to be in pairs)
typedef struct {
  int moisture; //!< Moisture
  long resistance; //!< Resistance
} values;

const long knownResistor = 4700;  // Constant value of known resistor in Ohms

int supplyVoltage;                // Measured supply voltage
int sensorVoltage;                // Measured sensor voltage

values valueOf[NUM_READS];        // Calculated moisture percentages and resistances to be sorted and filtered

int i;                            // Simple index variable

void setup()
  // initialize the digital pins as an output.
  // Pin 6,7 is for sensor 1
  // initialize the digital pin as an output.
  // Pin 6 is sense resistor voltage supply 1
  pinMode(6, OUTPUT);

  // initialize the digital pin as an output.
  // Pin 7 is sense resistor voltage supply 2
  pinMode(7, OUTPUT);

void presentation()
  sendSketchInfo("Soil Moisture Sensor Reverse Polarity", "1.0");
  present(CHILD_ID, S_MOISTURE);

void loop()

  Serial.print ("\t");
  Serial.println (average());
  long read1 = average();

  Serial.print ("\t");
  Serial.println (average());
  long read2= average();

  long sensor1 = (read1 + read2)/2;

  Serial.print ("resistance bias =" );
  Serial.println (read1-read2);
  Serial.print ("sensor bias compensated value = ");
  Serial.println (sensor1);
  Serial.println ();

  //send back the values
  // delay until next measurement (msec)

void measure (int phase_b, int phase_a, int analog_input)
  // read sensor, filter, and calculate resistance value
  // Noise filter: median filter

  for (i=0; i<NUM_READS; i++) {

    // Read 1 pair of voltage values
    digitalWrite(phase_a, HIGH);                 // set the voltage supply on
    supplyVoltage = analogRead(analog_input);   // read the supply voltage
    digitalWrite(phase_a, LOW);                  // set the voltage supply off

    digitalWrite(phase_b, HIGH);                 // set the voltage supply on
    sensorVoltage = analogRead(analog_input);   // read the sensor voltage
    digitalWrite(phase_b, LOW);                  // set the voltage supply off

    // Calculate resistance
    // the 0.5 add-term is used to round to the nearest integer
    // Tip: no need to transform 0-1023 voltage value to 0-5 range, due to following fraction
    long resistance = (knownResistor * (supplyVoltage - sensorVoltage ) / sensorVoltage) ;

    Serial.print (resistance);
    Serial.print ("\t");

// Averaging algorithm
void addReading(long resistance)
  buffer[idx] = resistance;
  if (idx >= NUM_READS) {
    idx = 0;

long average()
  long sum = 0;
  for (int cnt = 0; cnt < NUM_READS; cnt++) {
    sum += buffer[cnt];
  return (long)(sum / NUM_READS);

HA Logs

2020-02-25 15:58:18 WARNING (MainThread) [mysensors] Child 0 is unknown
2020-02-25 15:58:50 WARNING (MainThread) [mysensors] Child 0 is unknown
2020-02-25 15:59:21 WARNING (MainThread) [mysensors] Child 0 is unknown
2020-02-25 15:59:49 WARNING (MainThread) [mysensors] Not a valid message: Not valid message sub-type: 35 for dictionary value @ data['sub_type']
2020-02-25 15:59:49 WARNING (MainThread) [mysensors] Child 0 is unknown

A bit old topic here but I have the exact same problem. Did you get a solution for this?

I was able to fix this issue by declaring the mysensors library version in configuration.yaml.

add: version: “2.3”, or whatever version you are using.

Aha It works! Thanks!

Glad I could help!