1 files changed, 95 insertions, 0 deletions
diff --git a/dev_scripts/sen15901vane.py b/dev_scripts/sen15901vane.py
new file mode 100644
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--- /dev/null
+++ b/dev_scripts/sen15901vane.py
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+from gpiozero import MCP3008
+import time
+import math
+
+adc = MCP3008(channel=0)
+count = 0
+"""
+volts key pairs created with the below + known values from datasheet
+    # create voltage divider for use with MCP3008 ADC
+    def volt_div(r1, r2, vIn):
+        vOut = (vIn * r2)/(r1 + r2)
+        return round(vOut,3)
+
+    # calculate vOut values for each wind direction using known resistances from datasheet, 3.3 V from RPi and 4.7K ohm resistor
+
+    resistances = [33000, 6570, 8200, 891, 1000, 688, 2200, 1410, 390, 3140, 16000, 14120, 120000, 42120, 64900, 21880]
+
+    for i in range(len(resistances)):
+        print(resistances[i],volt_div(4700, resistances[i], 3.3))
+
+4.7K resistor
+volts = {0.4: "0.0 N",
+        1.4: "22.5 NNE",
+        1.2: "45.0 NE",
+        2.8: "67.5 ENE",
+        2.7: "90.0 E",
+        2.9: "112.5 ESE",
+        2.2: "135.0 SE",
+        2.5: "157.5 SSE",
+        1.8: "180.0 S",
+        2.0: "202.5 SSW",
+        0.7: "225.0 SW",
+        0.8: "247.5 WSW",
+        0.1: "270.0 W",
+        0.3: "292.5 WNW",
+        0.2: "315.0 NW",
+        0.6: "337.5 NNW"}
+"""
+# 5K resistor
+volts = {1.87: 0.0,
+        2.04: 22.5,
+        0.79: 45.0,
+        0.80: 45.0,
+        0.88: 67.5,
+        0.13: 90.0,
+        0.36: 112.5,
+        0.24: 135.0,
+        0.62: 157.5,
+        0.44: 180.0,
+        1.44: 202.5,
+        1.27: 225.0,
+        2.81: 247.5,
+        2.76: 270.0,
+        2.91: 292.5,
+        2.31: 315.0,
+        2.59: 337.5}
+
+def getAverage(angles):
+    sinSum = 0.0
+    cosSum = 0.0
+
+    for angle in angles:
+        r = math.radians(angle)
+        sinSum += math.sin(r)
+        cosSum += math.cos(r)
+
+    flen = float(len(angles))
+    s = sinSum / flen
+    c = cosSum / flen
+    arc = math.degrees(math.atan(s / c))
+    average = 0.0
+
+    if s > 0 and c > 0:
+        average = arc
+    elif c <0:
+        average = arc + 180
+    elif s < 0 and c > 0:
+        average = arc + 360
+
+    return 0.0 if average == 360 else average
+
+def getValue(length=5):
+    data = []
+    startTime = time.time()
+
+    while time.time() - startTime <= length:
+        wind = round(adc.value*3.3,2)
+        if not wind in volts: # keep only good measurements
+            print("Unknown value: " + str(wind))
+        else:
+            data.append(volts[wind])
+            
+    return getAverage(data)
+
+getValue()