service: text.set_value
data:
  value: "967067"
target:
  entity_id: text.water_meter_100_2

(change 967067 with the value you want to add to the current counter)

The service "notify.mysensors" seems to be deprecated by Home Assistant.

But: I do not really understand, how to correctly send the VALUE_TO_ADD.

This is what I tried to add 967.067 m³:

service: notify.mysensors
data:
  message: VALUE_TO_ADD
  target: text.water_meter_100_2
  data: 967067

But I just get this error message:

Fehler beim Aufrufen des Diensts notify.mysensors. expected dict for dictionary value @ data['data']. Got None

These are my newly found entities:

What is wrong here?

For those who think MySensors is finished, the proof is in the pudding, thousands of systems are functional :earth_asia:

with these changes you will have:
1 - factory reset
2 - automatic home assistant entities creation
3 - counter correction from home assistant using service notify.mysensors
4 - fixed counter automatically incremented by 1 at each device restart (due to arduino library interrupt bug)
5- other tiny improvements

If i use a magnet, simple code will detect the pulse and the green led on the sensor lights up.

But no matter where I put that sensor near the meter it just doesn't seem to detect it. Not quite sure what's happening.

The meter i have is this one.
https://www.badgermeter.com/resources/add29b88-1ffb-49c9-80ab-bb8697bd6d1a/absolute digital encoder product data sheet ade-ds-00183-en.pdf/

Not sure if anyone has any recommendation on which hall effect sensor would be the best for this but ill take suggestions lol

My sensor I am testing with is
3144E Hall Effect Sensor

Doesn't have a sensitivity dial but the recommended one on this build page didn't either.

!TSM:INIT:TSP FAIL

See https://www.mysensors.org/build/parser: There's a problem in the initialisation of your transceiver (whatever it may be). So first check wiring, see https://forum.mysensors.org/topic/666/read-this-first-it-could-save-you-a-lot-of-time for further details. If that doesn't help, imo you should open up a seperate thread.

16:57:15.660 -> 10091 TSM:FAIL:RE-INIT
16:57:15.660 -> 10093 TSM:INIT
16:57:15.660 -> 10101 !TSM:INIT:TSP FAIL
16:57:15.660 -> 10103 TSM:FAIL:CNT=2
16:57:15.660 -> 10107 TSM:FAIL:DIS
16:57:15.713 -> 10111 TSF:TDI:TSL

32319 TSF:MSG:SEND,6-6-0-0,s=1,c=2,t=24,pt=0,l=0,sg=0,ft=0,st=OK:

Logparser states: there was nothing counted (empty payload). So make sure, there really was counted anything.
(I didn't check your sketch, just assuming, it's the default one and everything is wired correctly; if that's the case, you should be able to see a different payload than nothing or "0", that your controller might treat as non existent).

 __  __       ____
|  \/  |_   _/ ___|  ___ _ __  ___  ___  _ __ ___
| |\/| | | | \___ \ / _ \ `_ \/ __|/ _ \| `__/ __|
| |  | | |_| |___| |  __/ | | \__ \  _  | |  \__ \
|_|  |_|\__, |____/ \___|_| |_|___/\___/|_|  |___/
        |___/                      2.3.0

16 MCO:BGN:INIT NODE,CP=RNNNA---,VER=2.3.0
26 TSM:INIT
28 TSF:WUR:MS=0
34 !TSM:INIT:TSP FAIL
36 TSM:FAIL:CNT=1
38 TSM:FAIL:DIS
40 TSF:TDI:TSL
 
 __  __       ____
|  \/  |_   _/ ___|  ___ _ __  ___  ___  _ __ ___
| |\/| | | | \___ \ / _ \ `_ \/ __|/ _ \| `__/ __|
| |  | | |_| |___| |  __/ | | \__ \  _  | |  \__ \
|_|  |_|\__, |____/ \___|_| |_|___/\___/|_|  |___/
        |___/                      2.3.0

16 MCO:BGN:INIT NODE,CP=RNNNA---,VER=2.3.0
26 TSM:INIT
28 TSF:WUR:MS=0
34 TSM:INIT:TSP OK
36 TSM:INIT:STATID=6
38 TSF:SID:OK,ID=6
40 TSM:FPAR
77 TSF:MSG:SEND,6-6-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
532 TSF:MSG:READ,0-0-6,s=255,c=3,t=8,pt=1,l=1,sg=0:0
538 TSF:MSG:FPAR OK,ID=0,D=1
624 TSF:MSG:READ,31-31-6,s=255,c=3,t=8,pt=1,l=1,sg=0:1
1267 TSF:MSG:READ,21-21-6,s=255,c=3,t=8,pt=1,l=1,sg=0:1
1546 TSF:MSG:READ,41-41-6,s=255,c=3,t=8,pt=1,l=1,sg=0:1
2088 TSM:FPAR:OK
2088 TSM:ID
2091 TSM:ID:OK
2093 TSM:UPL
2097 TSF:MSG:SEND,6-6-0-0,s=255,c=3,t=24,pt=1,l=1,sg=0,ft=0,st=OK:1
2103 TSF:MSG:READ,0-0-6,s=255,c=3,t=25,pt=1,l=1,sg=0:1
2109 TSF:MSG:PONG RECV,HP=1
2113 TSM:UPL:OK
2115 TSM:READY:ID=6,PAR=0,DIS=1
2119 TSF:MSG:SEND,6-6-0-0,s=255,c=3,t=15,pt=6,l=2,sg=0,ft=0,st=OK:0100
2127 TSF:MSG:READ,0-0-6,s=255,c=3,t=15,pt=6,l=2,sg=0:0100
2138 TSF:MSG:SEND,6-6-0-0,s=255,c=0,t=17,pt=0,l=5,sg=0,ft=0,st=OK:2.3.0
2148 TSF:MSG:SEND,6-6-0-0,s=255,c=3,t=6,pt=1,l=1,sg=0,ft=0,st=OK:0
2242 TSF:MSG:READ,0-0-6,s=255,c=3,t=6,pt=0,l=1,sg=0:M
2250 TSF:MSG:SEND,6-6-0-0,s=255,c=3,t=11,pt=0,l=11,sg=0,ft=0,st=OK:Water Meter
2260 TSF:MSG:SEND,6-6-0-0,s=255,c=3,t=12,pt=0,l=3,sg=0,ft=0,st=OK:1.1
2273 TSF:MSG:SEND,6-6-0-0,s=1,c=0,t=21,pt=0,l=0,sg=0,ft=0,st=OK:
2281 MCO:REG:REQ
2289 TSF:MSG:SEND,6-6-0-0,s=255,c=3,t=26,pt=1,l=1,sg=0,ft=0,st=OK:2
2297 TSF:MSG:READ,0-0-6,s=255,c=3,t=27,pt=1,l=1,sg=0:1
2304 MCO:PIM:NODE REG=1
2306 MCO:BGN:STP
2310 TSF:MSG:SEND,6-6-0-0,s=1,c=2,t=24,pt=0,l=0,sg=0,ft=0,st=OK:
2318 MCO:BGN:INIT OK,TSP=1
32319 TSF:MSG:SEND,6-6-0-0,s=1,c=2,t=24,pt=0,l=0,sg=0,ft=0,st=OK:

Is it possible to get any help on this page or not?

Crying out loud most likely will not help...
Seems your setup is a little special, so just some assumptions from one using a serial GW and not MyS-MQTT:
Your controller is asked for sending an initial value, but has none yet. So no answer is sent out. Triggering the counter on Node side could help to send one (after waiting time has passed). Then have a look at your controller, if there's a value available. If, you might set the correct value, restart your node afterwards and see, if everything now works as expected?

// Enable debug prints to serial monitor
#define MY_DEBUG

// Enable and select radio type attached
#define MY_RADIO_RF24
#define MY_NODE_ID 6
//#define MY_RADIO_NRF5_ESB
//#define MY_RADIO_RFM69
//#define MY_RADIO_RFM95

#include <MySensors.h>

#define DIGITAL_INPUT_SENSOR 3                  // The digital input you attached your sensor.  (Only 2 and 3 generates interrupt!)

#define PULSE_FACTOR 1000                       // Number of blinks per m3 of your meter (One rotation/liter)

#define SLEEP_MODE false                        // flowvalue can only be reported when sleep mode is false.

#define MAX_FLOW 40                             // Max flow (l/min) value to report. This filters outliers.

#define CHILD_ID 1                              // Id of the sensor child

uint32_t SEND_FREQUENCY =
    30000;           // Minimum time between send (in milliseconds). We don't want to spam the gateway.

MyMessage flowMsg(CHILD_ID,V_FLOW);
MyMessage volumeMsg(CHILD_ID,V_VOLUME);
MyMessage lastCounterMsg(CHILD_ID,V_VAR1);

double ppl = ((double)PULSE_FACTOR)/1000;        // Pulses per liter

volatile uint32_t pulseCount = 0;
volatile uint32_t lastBlink = 0;
volatile double flow = 0;
bool pcReceived = false;
uint32_t oldPulseCount = 0;
uint32_t newBlink = 0;
double oldflow = 0;
double volume =0;
double oldvolume =0;
uint32_t lastSend =0;
uint32_t lastPulse =0;

void setup()
{
  // initialize our digital pins internal pullup resistor so one pulse switches from high to low (less distortion)
  pinMode(DIGITAL_INPUT_SENSOR, INPUT_PULLUP);

  pulseCount = oldPulseCount = 0;

  // Fetch last known pulse count value from gw
  request(CHILD_ID, V_VAR1);

  lastSend = lastPulse = millis();

  attachInterrupt(digitalPinToInterrupt(DIGITAL_INPUT_SENSOR), onPulse, FALLING);
}

void presentation()
{
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("Water Meter", "1.1");

  // Register this device as Water flow sensor
  present(CHILD_ID, S_WATER);
}

void loop()
{
  uint32_t currentTime = millis();

  // Only send values at a maximum frequency or woken up from sleep
  if (SLEEP_MODE || (currentTime - lastSend > SEND_FREQUENCY)) {
    lastSend=currentTime;

    if (!pcReceived) {
      //Last Pulsecount not yet received from controller, request it again
      request(CHILD_ID, V_VAR1);
      return;
    }

    if (!SLEEP_MODE && flow != oldflow) {
      oldflow = flow;

      Serial.print("l/min:");
      Serial.println(flow);

      // Check that we don't get unreasonable large flow value.
      // could happen when long wraps or false interrupt triggered
      if (flow<((uint32_t)MAX_FLOW)) {
        send(flowMsg.set(flow, 2));                   // Send flow value to gw
      }
    }

    // No Pulse count received in 2min
    if(currentTime - lastPulse > 120000) {
      flow = 0;
    }

    // Pulse count has changed
    if ((pulseCount != oldPulseCount)||(!SLEEP_MODE)) {
      oldPulseCount = pulseCount;

      Serial.print("pulsecount:");
      Serial.println(pulseCount);

      send(lastCounterMsg.set(pulseCount));                  // Send  pulsecount value to gw in VAR1

      double volume = ((double)pulseCount/((double)PULSE_FACTOR));
      if ((volume != oldvolume)||(!SLEEP_MODE)) {
        oldvolume = volume;

        Serial.print("volume:");
        Serial.println(volume, 3);

        send(volumeMsg.set(volume, 3));               // Send volume value to gw
      }
    }
  }
  if (SLEEP_MODE) {
    sleep(SEND_FREQUENCY);
  }
}

void receive(const MyMessage &message)
{
  if (message.type==V_VAR1) {
    uint32_t gwPulseCount=message.getULong();
    pulseCount += gwPulseCount;
    flow=oldflow=0;
    Serial.print("Received last pulse count from gw:");
    Serial.println(pulseCount);
    pcReceived = true;
  }
}

void onPulse()
{
  if (!SLEEP_MODE) {
    uint32_t newBlink = micros();
    uint32_t interval = newBlink-lastBlink;

    if (interval!=0) {
      lastPulse = millis();
      if (interval<500000L) {
        // Sometimes we get interrupt on RISING,  500000 = 0.5 second debounce ( max 120 l/min)
        return;
      }
      flow = (60000000.0 /interval) / ppl;
    }
    lastBlink = newBlink;
  }
  pulseCount++;
}```

2019-07-04 23:24:05 DEBUG (MainThread) [homeassistant.components.mqtt] Received message on mygateway1-out/6/255/3/0/11: b'Water Meter',
2019-07-04 23:24:05 DEBUG (MainThread) [mysensors.gateway_mqtt] Receiving 6;255;3;0;11;Water Meter,
2019-07-04 23:24:23 DEBUG (MainThread) [homeassistant.components.mqtt] Received message on mygateway1-out/6/255/3/0/11: b'Water Meter',
2019-07-04 23:24:23 DEBUG (MainThread) [mysensors.gateway_mqtt] Receiving 6;255;3;0;11;Water Meter

Has this happened to anyone else? It's powered by 5V, it's the LED losing power or the photosensor losing sensitivity? Any ideas?
Thanks.