A small personal project bringing together some hype components. The initial goal was to build the cheapest wifi connected thermometer.

The temperature is collected from a DS1820 by an ESP-01. The data is then sent by wifi to a raspberry pi relay (which I already owned and was used as a print server). The raspberry send the datas collected from all the sensors to a influxdb/grafana instance.

The raspberry code is based on a Flask microservice which relays the data to the configured influxdb server. The microservice lifecycle is managed with Supervisord

The ESP8266 code brings together the onewire protocol to read data from the DS1820 and the ESP8266WiFi code to send a HTTP request. My ESP-01 is powered from 2 AA batteries, and customized according like this to lower power consumption.

• ESP-01 - < 2$
• DS1820 - < 1$
• AAA Holder - < 1$
• Resistors ( 1x 4.7k & 3x 2.2k) - < 1$