Hi all,
As I think a lot of you have tried, I am building a project that consists of measuring the soil moisture, if it drops below a certain value, trigger an alarm of sorts.
So I bought a Capacitive Moisture Sensor (It looks like this one)
I made a simple sketch (on a nodeMCU) that reads the value of the sensor and sends it to a webpage. Then goes to deepsleep and wakes up in about an hour. And send the reading again.
I did a baseline test (Dipped the sensor in water -> Raw Reading was around 400 and Hold it in the air -> Raw Reading was about 850).
Next up I wanted to see what it does when I put it in actual soil. (In a pot of a House plant.)
The reading I get are strange:
2018-11-29 23:11:28 plant 764
2018-11-30 00:08:43 plant 762
2018-11-30 01:06:18 plant 761
2018-11-30 02:03:20 plant 760
2018-11-30 03:00:42 plant 759
2018-11-30 03:58:02 plant 758
2018-11-30 04:54:53 plant 758
2018-11-30 05:52:12 plant 757
2018-11-30 06:49:42 plant 756
2018-11-30 07:46:41 plant 754
2018-11-30 08:44:07 plant 754
2018-11-30 09:41:56 plant 754
2018-11-30 10:39:14 plant 752
2018-11-30 11:36:58 plant 749
2018-11-30 12:34:12 plant 749
2018-11-30 13:31:43 plant 749
2018-11-30 14:29:29 plant 747
2018-11-30 15:26:47 plant 746
2018-11-30 16:24:30 plant 745
2018-11-30 17:22:14 plant 745
2018-11-30 18:19:39 plant 744
2018-11-30 19:17:00 plant 740
2018-11-30 20:14:09 plant 739
2018-11-30 21:11:31 plant 738
2018-11-30 22:09:17 plant 739
2018-11-30 23:07:12 plant 738
2018-12-01 00:03:54 plant 738
2018-12-01 01:01:26 plant 737
2018-12-01 01:58:15 plant 735
2018-12-01 02:55:32 plant 736
2018-12-01 03:53:01 plant 735
2018-12-01 04:50:17 plant 735
2018-12-01 05:47:39 plant 733
2018-12-01 06:44:45 plant 732
2018-12-01 07:42:09 plant 732
2018-12-01 08:39:21 plant 729
2018-12-01 09:36:25 plant 728
2018-12-01 10:33:51 plant 726
2018-12-01 11:31:24 plant 724
2018-12-01 12:28:31 plant 725
2018-12-01 13:26:01 plant 725
2018-12-01 14:23:21 plant 724
2018-12-01 15:20:19 plant 723
2018-12-01 16:17:51 plant 724
2018-12-01 17:15:05 plant 723
2018-12-01 18:12:13 plant 723
2018-12-01 19:09:59 plant 721
2018-12-01 20:07:32 plant 720
2018-12-01 21:04:31 plant 719
2018-12-01 22:02:02 plant 714
2018-12-01 22:59:36 plant 714
2018-12-01 23:56:47 plant 715
2018-12-02 00:54:14 plant 715
2018-12-02 01:51:30 plant 713
2018-12-02 02:48:36 plant 712
2018-12-02 03:46:08 plant 714
2018-12-02 04:43:36 plant 710
2018-12-02 05:41:18 plant 708
2018-12-02 06:38:22 plant 710
2018-12-02 07:35:35 plant 710
2018-12-02 08:32:52 plant 711
2018-12-02 09:30:38 plant 710
2018-12-02 10:27:52 plant 710
As you can see here the value drops. (According to the baseline) it means that the soil is getting wetter.
Do you guys have any idea what I am doing wrong? (Or what other conditions are that pollutes the readings?)
Thanks in advance