DHT11 locally on a ESP8266 MQTT Gateway
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Hi
Im trying to get my ESP8266 MQTT Gateway with a locally attached DHT11 sensor to work and I almost got it.
My problem is that the temp im reading is waaaay off. See screenshot
Any help would be appreciated.
The sketch im using is this:
/** * 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 * The ESP8266 MQTT gateway sends radio network (or locally attached sensors) data to your MQTT broker. * The node also listens to MY_MQTT_TOPIC_PREFIX and sends out those messages to the radio network * * LED purposes: * - To use the feature, uncomment any of the MY_DEFAULT_xx_LED_PINs in your sketch * - RX (green) - blink fast on radio message recieved. In inclusion mode will blink fast only on presentation recieved * - TX (yellow) - blink fast on radio message transmitted. In inclusion mode will blink slowly * - ERR (red) - fast blink on error during transmission error or recieve crc error * * See http://www.mysensors.org/build/esp8266_gateway for wiring instructions. * nRF24L01+ ESP8266 * VCC VCC * CE GPIO4 * CSN/CS GPIO15 * SCK GPIO14 * MISO GPIO12 * MOSI GPIO13 * * Not all ESP8266 modules have all pins available on their external interface. * This code has been tested on an ESP-12 module. * The ESP8266 requires a certain pin configuration to download code, and another one to run code: * - Connect REST (reset) via 10K pullup resistor to VCC, and via switch to GND ('reset switch') * - Connect GPIO15 via 10K pulldown resistor to GND * - Connect CH_PD via 10K resistor to VCC * - Connect GPIO2 via 10K resistor to VCC * - Connect GPIO0 via 10K resistor to VCC, and via switch to GND ('bootload switch') * * Inclusion mode button: * - Connect GPIO5 via switch to GND ('inclusion switch') * * Hardware SHA204 signing is currently not supported! * * Make sure to fill in your ssid and WiFi password below for ssid & pass. */ // Enable debug prints to serial monitor #define MY_DEBUG // Use a bit lower baudrate for serial prints on ESP8266 than default in MyConfig.h #define MY_BAUD_RATE 9600 // Enables and select radio type (if attached) //#define MY_RADIO_NRF24 #define MY_RADIO_RFM69 #define MY_GATEWAY_MQTT_CLIENT #define MY_GATEWAY_ESP8266 // Set this node's subscribe and publish topic prefix #define MY_MQTT_PUBLISH_TOPIC_PREFIX "mygateway1-out" #define MY_MQTT_SUBSCRIBE_TOPIC_PREFIX "mygateway1-in" // Set MQTT client id #define MY_MQTT_CLIENT_ID "mysensors-1" // Enable these if your MQTT broker requires usenrame/password //#define MY_MQTT_USER "username" //#define MY_MQTT_PASSWORD "password" // Set WIFI SSID and password #define MY_ESP8266_SSID "SSID" #define MY_ESP8266_PASSWORD "PASSWORD" // Set the hostname for the WiFi Client. This is the hostname // it will pass to the DHCP server if not static. #define MY_ESP8266_HOSTNAME "mqtt-sensor-gateway" // Enable MY_IP_ADDRESS here if you want a static ip address (no DHCP) //#define MY_IP_ADDRESS 192,168,178,87 // If using static ip you need to define Gateway and Subnet address as well //#define MY_IP_GATEWAY_ADDRESS 192,168,178,1 //#define MY_IP_SUBNET_ADDRESS 255,255,255,0 // MQTT broker ip address. #define MY_CONTROLLER_IP_ADDRESS 192, 168, 1 , 87 // The MQTT broker port to to open #define MY_PORT 1883 #include <SPI.h> #include <ESP8266WiFi.h> #include <MySensors.h> #include <DHT.h> //DHT11 stuff, This node on MQTT mygateway1-out/X/1/1/0/0 for temperature and mygateway1-out/X/0/1/0/1 for humidity #define DHT_DATA_PIN 5 #define SENSOR_TEMP_OFFSET 0 static const uint8_t FORCE_UPDATE_N_READS = 10; static const uint64_t UPDATE_INTERVAL = 2000; #define CHILD_ID_HUM 0 #define CHILD_ID_TEMP 1 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; /* // Enable inclusion mode #define MY_INCLUSION_MODE_FEATURE // Enable Inclusion mode button on gateway #define MY_INCLUSION_BUTTON_FEATURE // 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 1 // Set blinking period #define MY_DEFAULT_LED_BLINK_PERIOD 300 // Flash leds on rx/tx/err #define MY_DEFAULT_ERR_LED_PIN 16 // Error led pin #define MY_DEFAULT_RX_LED_PIN 16 // Receive led pin #define MY_DEFAULT_TX_LED_PIN 16 // the PCB, on board LED */ void presentation() { // Send the sketch version information to the gateway sendSketchInfo("TemperatureAndHumidity", "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 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) wait(dht.getMinimumSamplingPeriod()); } 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 wait(UPDATE_INTERVAL); }
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I can also add that the room in measuring is quite cold. Like about 13-16 degrees so its not only a decimal error.
I might have a faulty DHT11 module but im not shure.
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@Yeitso What DHT11 library are you using? It might not be compatinly with ESP8266...
You could try the library describved here: https://techtutorialsx.wordpress.com/2016/04/24/esp8266-read-dht11-measurements/
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Yeah im gonna try to switch to adafruits lib. Atm im using the one from mysensors.
