How to include the battery measurement?

tlpeter

I am trying to build a sensor with a DHT22 and for now on a solar panel and a battery.
I want to see the battery level within Domoticz.
I cannot seem to merge both the battery sketch and the DHT sketch together.
Most of the times i get an error about a { being in a place where it should not belong.
I think i lost it :smiley: and i am going mad soon.
Also how to send the battery level to Domoticz? i tried the battery sketch alone and nothing happens.

sundberg84

@tlpeter

Most of the times i get an error about a { being in a place where it should not belong.

Its easier for us if you post the code so we can have a look if you want help :)

Also how to send the battery level to Domoticz?

Well, before 2.0 it was gw.sendBatteryLevel(batteryPcnt); and now it is sendBatteryLevel(batteryPcnt);
The battery% needs to be attached to a sensor - so it will be displayed in the deviced tab if you look at the device/sensor.

tlpeter

sendBatteryLevel doesn't do anything.
I have modified it a bit and now i have some readings.
I will do a bit more playing to see where i will end.

sundberg84

@tlpeter - it does, but it needs to be together with a sensor. You will find it in "devices".

sundberg84

tlpeter

I have voltage now (utility) and a percentage under devices.
I have read somewhere that the percentage is depending on the last sensors poll so i will now try to add the DHT part in to the sketch.

tlpeter

I have the voltage part working and i think also the battery percentage with it.
I build the sketch like this. Can you have a little look?

/**
 * 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 <henrik.ekblad@mysensors.org>
 * Copyright (C) 2013-2015 Sensnology AB
 * Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
 *
 * Documentation: http://www.mysensors.org
 * Support Forum: http://forum.mysensors.org
 *
 * 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.
 *
 *******************************
 *
 * DESCRIPTION
 *
 * This is an example that demonstrates how to report the battery level for a sensor
 * Instructions for measuring battery capacity on A0 are available here:
 * http://www.mysensors.org/build/battery
 * 
 */



// Enable debug prints to serial monitor
#define MY_DEBUG 

// Enable and select radio type attached
#define MY_RADIO_NRF24
//#define MY_RADIO_RFM69

#include <SPI.h>
#include <MySensors.h>
#include <DHT.h>

#define CHILD_ID_BATT 0
#define CHILD_ID_HUM 1
#define CHILD_ID_TEMP 2

#define DHT_DATA_PIN 3 // Set this to the pin you connected the DHT's data pin to
int BATTERY_SENSE_PIN = A0;  // select the input pin for the battery sense point

// Set this offset if the sensor has a permanent small offset to the real temperatures
#define SENSOR_TEMP_OFFSET 0

static const uint64_t UPDATE_INTERVAL = 30000;

// Force sending an update of the temperature after n sensor reads, so a controller showing the
// timestamp of the last update doesn't show something like 3 hours in the unlikely case, that
// the value didn't change since;
// i.e. the sensor would force sending an update every UPDATE_INTERVAL*FORCE_UPDATE_N_READS [ms]
static const uint8_t FORCE_UPDATE_N_READS = 10;

//unsigned long SLEEP_TIME = 9000;  // sleep time between reads (seconds * 1000 milliseconds)
int oldBatteryPcnt = 0;

float lastTemp;
float lastHum;
uint8_t nNoUpdatesTemp;
uint8_t nNoUpdatesHum;
boolean metric = true; 

MyMessage msgBatt(CHILD_ID_BATT, V_VOLTAGE);
MyMessage msgHum(CHILD_ID_HUM, V_HUM);
MyMessage msgTemp(CHILD_ID_TEMP, V_TEMP);
DHT dht;

void setup()  
{
   // use the 1.1 V internal reference
#if defined(__AVR_ATmega2560__)
   analogReference(INTERNAL1V1);
#else
   analogReference(INTERNAL);
#endif
//}

{
dht.setup(DHT_DATA_PIN); // set data pin of DHT sensor
  if (UPDATE_INTERVAL <= dht.getMinimumSamplingPeriod()) {
    Serial.println("Warning: UPDATE_INTERVAL is smaller than supported by the sensor!");
  }
  // Sleep for the time of the minimum sampling period to give the sensor time to power up
  // (otherwise, timeout errors might occure for the first reading)
  sleep(dht.getMinimumSamplingPeriod());
}
}
void presentation() {
   // Send the sketch version information to the gateway and Controller
   sendSketchInfo("Battery Meter", "1.0");

   present(CHILD_ID_BATT, S_MULTIMETER);
   wait(20);
   present(CHILD_ID_HUM, S_HUM);
   wait(20);
   present(CHILD_ID_TEMP, S_TEMP);
   wait(20);
   metric = getConfig().isMetric;

}
void loop()
{
   // get the battery Voltage
   int sensorValue = analogRead(BATTERY_SENSE_PIN);
   #ifdef MY_DEBUG
   Serial.println(sensorValue);
   #endif
   
   // 1M, 470K divider across battery and using internal ADC ref of 1.1V
   // Sense point is bypassed with 0.1 uF cap to reduce noise at that point
   // ((1e6+470e3)/470e3)*1.1 = Vmax = 3.44 Volts
   // 3.44/1023 = Volts per bit = 0.003363075
   
   int batteryPcnt = sensorValue / 10;

   #ifdef MY_DEBUG
   float batteryV  = sensorValue * 0.003363075;
   Serial.print("Battery Voltage: ");
   Serial.print(batteryV);
   Serial.println(" V");

   Serial.print("Battery percent: ");
   Serial.print(batteryPcnt);
   Serial.println(" %");
   #endif

   if (oldBatteryPcnt != batteryPcnt) {
     // Power up radio after sleep
     send(msgBatt.set(batteryV, 1));
    //sendBatteryLevel(batteryPcnt);
     oldBatteryPcnt = batteryPcnt;
   }

   {  
  // Force reading sensor, so it works also after sleep()
  dht.readSensor(true);
  
  // Get temperature from DHT library
  float temperature = dht.getTemperature();
  if (isnan(temperature)) {
    Serial.println("Failed reading temperature from DHT!");
  } else if (temperature != lastTemp || nNoUpdatesTemp == FORCE_UPDATE_N_READS) {
    // Only send temperature if it changed since the last measurement or if we didn't send an update for n times
    lastTemp = temperature;
    if (!metric) {
      temperature = dht.toFahrenheit(temperature);
    }
    // Reset no updates counter
    nNoUpdatesTemp = 0;
    temperature += SENSOR_TEMP_OFFSET;
    send(msgTemp.set(temperature, 1));

    #ifdef MY_DEBUG
    Serial.print("T: ");
    Serial.println(temperature);
    #endif
  } else {
    // Increase no update counter if the temperature stayed the same
    nNoUpdatesTemp++;
  }

  // Get humidity from DHT library
  float humidity = dht.getHumidity();
  if (isnan(humidity)) {
    Serial.println("Failed reading humidity from DHT");
  } else if (humidity != lastHum || nNoUpdatesHum == FORCE_UPDATE_N_READS) {
    // Only send humidity if it changed since the last measurement or if we didn't send an update for n times
    lastHum = humidity;
    // Reset no updates counter
    nNoUpdatesHum = 0;
    send(msgHum.set(humidity, 1));
    
    #ifdef MY_DEBUG
    Serial.print("H: ");
    Serial.println(humidity);
    #endif
  } else {
    // Increase no update counter if the humidity stayed the same
    nNoUpdatesHum++;
  }
   //sleep(SLEEP_TIME);
   sleep(UPDATE_INTERVAL);
   }}```

sundberg84

@tlpeter - Im not a coding guy, but it looks good to me.
Myself i build my sketches, test and look at serial output and Domoticz output. When im happy with the result - i go for it.

This is going to create two devices i think, one humidity/temp and one voltage. The batterypct and voltage will be seperated from humidity/temp i think even if they belong together. If you want the procentage in devices for the right device you just skip the voltage part.

tlpeter

I have voltage now and a percentage at the devices.
Hum and temp do work fine.
I only sucked all the juice out of the battery so it is charging now by the little solar panel.
I found out that 2,4V was really the lowest voltage that worked :smile:

sundberg84

@tlpeter If you want to suck more juice out of the batteries use a DC-DC step up booster: https://www.mysensors.org/store/#regulators then you can go down to 0.9V :)

tlpeter

I will buy one later :smile:
This is just to play with as i wanted to know how the battery measurement works.

clio75

@tlpeter said:

if (oldBatteryPcnt != batteryPcnt) {
// Power up radio after sleep
send(msgBatt.set(batteryV, 1));
//sendBatteryLevel(batteryPcnt);
oldBatteryPcnt = batteryPcnt;
}

Hi, This part should not have been updated

this part is icluded in the lib
So leave it like the exsample
if (oldBatteryPcnt != batteryPcnt) {
// Power up radio after sleep
sendBatteryLevel(batteryPcnt);
oldBatteryPcnt = batteryPcnt;
}

For sending over your voltage you need one additional

send(msgBatt.set(batteryV, 1));

Good luck

How to include the battery measurement?

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