Build a network of DHT temperature and humidity sensors using the ESP8266WiFi.
Monitor several ESP8266+DHT (DHT22, DHT11 ...) sensors from a single web page. This version can auto detect the sensor type and create or connect to an access point that collects the Temperature And Humidity from up to 7 clients the information is displayed in a single web page. If the device detects that the AP exists it becomes a client publishing its own sensor data that the AP can collect.
After setting up the first ESP8266 + DHT22 temperature sensor I built a second for the other side of the room I wanted to monitor both from a single device like a smart phone so I setup one of the devices as an access point capable of serving a WEB page on the local network this page displays one or more of the temperature sensors. Each device registers it's hostname using mDNS I used DigiTemp-AP for the host name allowing access of the monitoring device using the URL "http://DigiTemp-AP.local". I have tested with 6 sensors the maximum number of concurrent connections stated for ESP8266WiFi is 8 therefore it should work with up to 7 sensors leaving 1 connection for the smart phone, tablet or PC.
Note: I replaced the Adafruit DHT Library DHT.h and DHT.cpp with modified local files to allow auto sensing of the DHT sensor type. Now I can easily swap sensors without re programming the ESP.
Files
- DHT.h,cpp Modified Adafruit DHT files
- DigiTempESP_V4.h Common functions
- DigiTempESP_V4.ino Arduino sketch launching point
- Sensor.h,cpp Wrapper for the DHT sensor files
- UserSettings.h Changeable setting such as IP, username, password ...
Some common functions
- BinLED Built in LED
- TimeCheck Monitor time elapse
- Uptime Monitor time from last boot
Libraries
- Adafruit_Unified_Sensor
- ESP8266mDNS
- ESP8266WebServer
- ESP8266WiFi