SoilHumiditySensor: Difference between revisions
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== Hardware == | == Hardware == | ||
It got [https://nl.aliexpress.com/item/32882371718.html these capacitive ones] from Aliexpress. | It got [https://nl.aliexpress.com/item/32882371718.html these capacitive ones] from Aliexpress. | ||
I've connected it up as follows: | |||
* probe GND (black) to Wemos D1 mini pin D5 | |||
* probe VCC (red) to Wemos D1 mini pin D0 | |||
* probe AOUT (yellow) to Wemos D1 mini pin A0 | |||
This way, the wire with the 3-pin connector can simply be plugged into the Wemos D1 mini, without having to modify the cable. | |||
The software puts a low level on pin D5 (to emulate GND) and a high level on pin D0 (to emulate VCC). | |||
The idea is that the current is low enough for this trick to work. | |||
== Software == | == Software == | ||
Revision as of 12:49, 12 May 2019
| Project SoilHumiditySensor | |
|---|---|
| |
| Investigation of soil humidity sensors | |
| Status | In progress |
| Contact | bertrik |
| Last Update | 2019-05-12 |
Introduction
A number of types of soil humidity sensors exist. Many have the problem that the electrodes corrode.
For example, see this video by Andreas Spiess that compares a couple of types.
References
Hardware
It got these capacitive ones from Aliexpress.
I've connected it up as follows:
- probe GND (black) to Wemos D1 mini pin D5
- probe VCC (red) to Wemos D1 mini pin D0
- probe AOUT (yellow) to Wemos D1 mini pin A0
This way, the wire with the 3-pin connector can simply be plugged into the Wemos D1 mini, without having to modify the cable.
The software puts a low level on pin D5 (to emulate GND) and a high level on pin D0 (to emulate VCC). The idea is that the current is low enough for this trick to work.
Software
See my github repository.
The software takes a measurement at a regular interval and sends it over MQTT.