As described in my post before i will start with a short description of the WEMOS D1 MINI, one of my first ESP8266 boards.

Basically i user the mini as test board and in varius combinations as sensor base in my home automation setup.

Basic features:

  • integrated usb-serial connector
  • integrated voltage regulator
  • powered by usb 5V or direct via pin 5V & 3.3V
  • reset button (pin RST)
  • onboard led (pin D4)
  • integrated 4MB memory

Most of my wemos i use with DHT22 or BME260 sensors and tasmota: https://github.com/arendst/Sonoff-Tasmota/wiki/Wemos-D1-Mini

Some i also use with one or two DS18B20 temperature sensors.

In all use cases i connect via mqtt and use node-red to push the mqtt values to an influxDB.

The mini has the advantage that it´s compact/small but have more exposed GPIOs like the ESP-01 for example. It´s also possible to make small setups with a connected D0 -> RST for deep sleep scenarios with very low effort while you have to soldering very small structures on the ESP-01.

Powering the mini with a 18560 battery and a deep sleep cycle of about 3600sec allows operation for several weeks or month without a fixed power source.






One of the best pinout descriptions and detail sites i know for the esp8266:

ESP8266 Pinout Reference: Which GPIO pins should you use?


Save Google API via Node-Red in influxDB & visualize with grafana

I was inspired by a video from Csongor Varga for a new project idea with my Node-Red. Basically he uses Node-Red for requesting the Google API and getting the travel time form home to work. My idea was then to request the data from the Google API and save them in my InfluxDB for further analytics.

I start with a Big Timer to limit the requests to a timeslot from 4:30am to 10:30am. Then i use the Switch and Join elements to limit the request to any tenth trigger. After that there is the http get with the Google API call.

For the following three change elements which extracts the values i want to save i use a json element for transforming the output of the http call.

The last join than aggregates the values to a new json which is than forwarded to the influxdb in a database called statistics.

The output than looks like this in the influxDB

> select * from travel_allach ORDER BY time DESC limit 1;
name: travel_allach
time distance duration duration_in_traffic value
---- -------- -------- ------------------- -----
1570212851482806984 60696 3331 3143

This is the output of the Grafana Visualization:



ESP Overview

Actual it´s nearly impossible to count all the variations of the actual ESP8266 and ESP32 developer boards availaible at amazon, bangoods and ali express. Neverthe less i´ll try to document some of the boards i actual use and what they´re good for in some of the next posts.  Over the time i´ve collected many of the „standard“ representatives and also some of the more unusual types. They all have in common that they´re available for hobby developer and electronics nerds.

The power supply for most of them needs  3.3V or 5V depends on if there are voltage converters included or not. The main use cases most people see in this little boards are building cheap little IoT devices on their own.

The start of my short introduction round will be the:


which was the first ESP8266 i´ve started with.

Over the time I collected several other devices, like the Sonoff Basic, Sonoff Mini, NodeMCU ESP8266, ESP01, ESP32, OBI WIFI plugs, LILYGO TTGO T-Journal ESP32, Geekcreit® ESP32-CAM WiFi + bluetooth Camera Module, HiGrow ESP32 and some others i will also try to describe and how or for what i´m using this.