REV 1.0
This project is still work in progress!
This sensor is intended to measure the soil moisture of plants and to send them by WIFI to a server for data evaluation. An ESP8266 module is used for the sender to send data over the air. A capacitive measuring method is used as a sensor to get moisture values. The basic framework of the sensor is based on the [Gies-O-Mat von Fred Ram]1.
A 18650 battery is to be used as power source, as this can have high capacities. A long life per battery can be guaranteed. It is assumed that the sensor can operate for up to 3 months at half-hour measurement - This must still be proven!
Layout was made with Eagle 7.72.
First try to model a case for the board in 3d
GPIO5 is now used to control Vin in smitt trigger to use less power when sensor is not measuring.
Reichelt Order List: https://www.reichelt.de/my/1310317
see also file https://github.com/lh84/moisture_sensor_esp12/blob/master/bom.txt
As software you can use the source code von Zentris3. Version 2.2 works pretty good with some small changes.
First test at 20/01/17 was pretty good with this new designed board.
I made a first prototype of the new design with etching at home. Looks und works pretty good for the first test.
You can see the live data from my first sensor prototype monitored in thingspeak: https://thingspeak.com/channels/210863/charts/1?width=1000&height=600&bgcolor=%23ffffff&color=%23d62020&results=240&type=line&update=15×cale=240
You have an idea how this sensor can be designed better? Then write me or send a request.
- Model case for board (fusion 360)
- Add battery monitoring with voltage devider (http://www.esp8266-projects.com/2015/03/internal-adc-esp8266.html)
- build first prototype
- check hardware (first prototype)
- check runtime with 18650 battry - see comments in #3
- test hardware in outdoor environment