A beginners question

[Hilltan]

I have put a DHT22 sensor to my serial gateway, and in the sketch code for the DHT22 sensor there is sleeping “code”, static const uint64_t UPDATE_INTERVAL = 60000; and on the end sleep(UPDATE_INTERVAL); . Will this affect the gateway forcing it to sleep or will this only affect the DHT sensor? My sketch:

// Enable debug prints to serial monitor
#define MY_DEBUG 


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

// Set LOW transmit power level as default, if you have an amplified NRF-module and
// power your radio separately with a good regulator you can turn up PA level. 
#define MY_RF24_PA_LEVEL RF24_PA_LOW

// Enable serial gateway
#define MY_GATEWAY_SERIAL

// Define a lower baud rate for Arduino's running on 8 MHz (Arduino Pro Mini 3.3V & SenseBender)
#if F_CPU == 8000000L
#define MY_BAUD_RATE 38400
#endif

// Flash leds on rx/tx/err
#define MY_LEDS_BLINKING_FEATURE
// Set blinking period
#define MY_DEFAULT_LED_BLINK_PERIOD 300

// Inverses the behavior of leds
//#define MY_WITH_LEDS_BLINKING_INVERSE

// Enable inclusion mode
#define MY_INCLUSION_MODE_FEATURE
// Enable Inclusion mode button on gateway
#define MY_INCLUSION_BUTTON_FEATURE

// Inverses behavior of inclusion button (if using external pullup)
//#define MY_INCLUSION_BUTTON_EXTERNAL_PULLUP

// Set inclusion mode duration (in seconds)
#define MY_INCLUSION_MODE_DURATION 60 
// Digital pin used for inclusion mode button
#define MY_INCLUSION_MODE_BUTTON_PIN  3 

// Uncomment to override default HW configurations
//#define MY_DEFAULT_ERR_LED_PIN 4  // Error led pin
//#define MY_DEFAULT_RX_LED_PIN  6  // Receive led pin
//#define MY_DEFAULT_TX_LED_PIN  5  // the PCB, on board LED

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

//DHT Begin

// Set this to the pin you connected the DHT's data pin to
#define DHT_DATA_PIN 8

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

// Sleep time between sensor updates (in milliseconds)
// Must be >1000ms for DHT22 and >2000ms for DHT11
static const uint64_t UPDATE_INTERVAL = 60000;

// 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;

#define CHILD_ID_HUM 10
#define CHILD_ID_TEMP 11

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

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

void setup()
{
  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
  sendSketchInfo("Getway+DHT", "1.1");
  
  // Register all sensors to gw (they will be created as child devices)
  present(CHILD_ID_HUM, S_HUM);
  present(CHILD_ID_TEMP, S_TEMP);
  
  metric = getConfig().isMetric;
}

void loop()      
{  
  // 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 for a while to save energy
  sleep(UPDATE_INTERVAL); 
}

[TheoL]

@Hilltan If you use sleep, an Arduino will go to sleep and is not able to receive any message. By using this

sleep(UPDATE_INTERVAL);

Your gateway will go to sleep and will not receive messages from other nodes. Which is kind of the main task of a gateway.

It should be

wait( UPDATE_INTERVAL );

Basic rule is. Use sleep only on battery powered nodes that don't have any incoming message. Use wait in all other circumstances.

ps. I put your sketch between 4 `

[Hilltan]

Thanks for a replay. I change sleep to wait then. What I was concerned about was to “read” to often from the DHT sensor. But I believe "static const uint64_t UPDATE_INTERVAL = 60000; " in the beginning will regulate this, so my gateway will not over read the DHT sensor?

[mfalkvidd]

@Hilltan the wait call will not return until the specified number of milliseconds has passed. So yes it will prevent from reading the dht too often.

[meanmrgreen]

About to built a dht / pir / repeater.
Since i cant Sleep it do i need to change all sleep with wait?

In the dht example there is a Sleep to let the sensor settle before Reading. Should this be a wait instead then?

[mfalkvidd]

@meanmrgreen yes

[meanmrgreen]

@mfalkvidd

Hmm i have a combined sketch of the pir and dht example that works fine on a node that Can Sleep for a bit and interrupt with change on the pir.

But if i take that sketch and change the Sleep with interrupt to a wait(sleep_time) the pir is not registrering movement between wait Times'.

FIf i remove the wait alltoghter the pir is reporting the status every ms instead with the result that the dht can't read the temp!

[mfalkvidd]

@meanmrgreen could you post your sketch?

[meanmrgreen]

this is it.

https://create.arduino.cc/editor/meanmrgreen/e7e0219e-139a-4e89-88da-e02f0864e9c6/preview

not sure of link worksge. on phone atm. will paste it from comp later if its not working.

[meanmrgreen]

/**
 * 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.
 *
 *******************************
 *
 * REVISION HISTORY
 * Version 1.0 - Henrik Ekblad
 * 
 * DESCRIPTION
 * Motion Sensor example using HC-SR501 
 * http://www.mysensors.org/build/motion
 *
 */
//Enable Repeater
#define MY_REPEATER_FEATURE

// Enable debug prints
#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>

unsigned long SLEEP_TIME = 120000; // Sleep time between reports (in milliseconds)
#define DIGITAL_INPUT_SENSOR 2   // The digital input you attached your motion sensor.  (Only 2 and 3 generates interrupt!)
#define DHT_DATA_PIN 4
#define CHILD_ID_MOT 1   // Id of the sensor child
#define CHILD_ID_HUM 0
#define CHILD_ID_TEMP 2

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

// Sleep time between sensor updates (in milliseconds)
// Must be >1000ms for DHT22 and >2000ms for DHT11
static const uint64_t UPDATE_INTERVAL = 120000;

// 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;

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

// Initialize motion message
MyMessage msg(CHILD_ID_MOT, V_TRIPPED);
MyMessage msgHum(CHILD_ID_HUM, V_HUM);
MyMessage msgTemp(CHILD_ID_TEMP, V_TEMP);
DHT dht;

void presentation()  {
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("PIR_DHT_REPEATER", "1.0");

  // Register all sensors to gw (they will be created as child devices)
  present(CHILD_ID_MOT, S_MOTION);
  present(CHILD_ID_HUM, S_HUM);
  present(CHILD_ID_TEMP, S_TEMP);

  metric = getConfig().isMetric;
}

void setup()  
{  
  pinMode(DIGITAL_INPUT_SENSOR, INPUT);      // sets the motion sensor digital pin as input
  
  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)
  wait(dht.getMinimumSamplingPeriod());
}

void loop()     
{     
  // Read digital motion value
  boolean tripped = digitalRead(DIGITAL_INPUT_SENSOR) == HIGH; 
      
  Serial.println(tripped);
  send(msg.set(tripped?"1":"0"));  // Send tripped value to gw 
  // Force reading sensor, so it works also after wait()
  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++;
  }

  // wait until interrupt comes in on motion sensor. Send update every two minute.
  wait(SLEEP_TIME);
}

[m26872]

@meanmrgreen You should use non-blocking code with millis() and if{}. Look e.g. at
https://forum.mysensors.org/topic/461/motion-sensor
https://forum.mysensors.org/topic/2717/repeater-node-with-sensor/12