From 5928f99e29046c60cdf9ac2c27d8b099b1ac4de2 Mon Sep 17 00:00:00 2001
From: Phil Howard <phil@gadgetoid.com>
Date: Fri, 28 Aug 2020 12:25:22 +0100
Subject: [PATCH] Add support for history

---
 library/grow/moisture.py | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/library/grow/moisture.py b/library/grow/moisture.py
index 66ca6bf..3d563e8 100644
--- a/library/grow/moisture.py
+++ b/library/grow/moisture.py
@@ -30,6 +30,8 @@ class Moisture(object):
 
         self._count = 0
         self._reading = 0
+        self._history = []
+        self._history_length = 200
         self._last_pulse = time.time()
         self._new_data = False
         self._wet_point = wet_point if wet_point is not None else 0.7
@@ -56,10 +58,23 @@ dtoverlay=spi0-cs,cs0_pin=14 # Re-assign CS0 from BCM 8 so that Grow can use it
         self._last_pulse = time.time()
         if self._time_elapsed >= 1.0:
             self._reading = self._count / self._time_elapsed
+            self._history.insert(0, self._reading)
+            self._history = self._history[:self._history_length]
             self._count = 0
             self._time_last_reading = time.time()
             self._new_data = True
 
+    @property
+    def history(self):
+        history = []
+
+        for moisture in self._history:
+            saturation = float(moisture - self._dry_point) / self.range
+            saturation = round(saturation, 3)
+            history.append(max(0.0, min(1.0, saturation)))
+
+        return history
+
     @property
     def _time_elapsed(self):
         return time.time() - self._time_last_reading