18 May 2015

It's IoT time! Wireless online thermometer with ESP8266 and DS18B20

IoT, Internet of Things, is not rocket science anymore. Grab an ESP8266 WiFi module, a USB-to-serial adapter and few wires later you are programming it through the familiar Arduino IDE. The most annoying part is providing 3.3 V at 300+ mA as power supply. That's about 10 USD if you already have a computer for programming.

For this initial test I am uploading my shack room temperature to thingspeak.com in the "ZYW Home" channel.

The circuit reads temperature every 60 seconds (almost 62 seconds, actually) and uploads it to the cloud. The temperature sensor is a 1-wire DS18B20. The dashboard shows the average temperature in buckets of 10 minutes and how many measurements have been made since power-on.

Incidentally the latter number provides two more information:
  1. power outage at home if "cycles" restart from 1
  2. xDSL outage or problems if there is a gap or no data upload
 I want to add another temperature sensor for outside and, when ESP-201 modules will come, a solar panel for reading solar illumination. Since ESP-201 allows deep-sleep state, the whole thing could even be battery powered and solar recharged.