ldt0028: Added support for LDT0-028 PZT film-based sensors

Signed-off-by: Sarah Knepper <sarah.knepper@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

examples/python/ldt0028.py

@@ -0,0 +1,66 @@
+# Author: Sarah Knepper <sarah.knepper@intel.com>
+# Copyright (c) 2014 Intel Corporation.
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+import time
+import array
+import pyupm_ldt0028 as ldt0028
+
+NUMBER_OF_SECONDS = 10
+SAMPLES_PER_SECOND = 50
+THRESHOLD = 100
+
+# Create the LDT0-028 Piezo Vibration Sensor object using AIO pin 0
+sensor = ldt0028.LDT0028(0)
+
+# Read the signal every 20 milliseconds for 10 seconds
+print 'For the next', NUMBER_OF_SECONDS, 'seconds,', \
+      SAMPLES_PER_SECOND, 'samples will be taken every second.\n'
+buffer = array.array('H')
+for i in range(0, NUMBER_OF_SECONDS * SAMPLES_PER_SECOND):
+    buffer.append(sensor.getSample())
+    time.sleep(1.0/SAMPLES_PER_SECOND)
+
+# Print the number of times the reading was greater than the threshold
+count = 0
+for i in range(0, NUMBER_OF_SECONDS * SAMPLES_PER_SECOND):
+    if buffer[i] > THRESHOLD:
+        count += 1
+print sensor.name(), ' exceeded the threshold value of', \
+        THRESHOLD, 'a total of', count, 'times,'
+print 'out of a total of', NUMBER_OF_SECONDS*SAMPLES_PER_SECOND, \
+        'reading.\n'
+
+# Print a graphical representation of the average value sampled
+# each second for the past 10 seconds, using a scale factor of 15
+print 'Now printing a graphical representation of the average reading '
+print 'each second for the last', NUMBER_OF_SECONDS, 'seconds.'
+SCALE_FACTOR = 15
+for i in range(0, NUMBER_OF_SECONDS):
+    sum = 0
+    for j in range(0, SAMPLES_PER_SECOND):
+        sum += buffer[i*SAMPLES_PER_SECOND+j]
+    average = sum / SAMPLES_PER_SECOND
+    stars_to_print = int(round(average / SCALE_FACTOR))
+    print '(' + repr(int(round(average))).rjust(4) + ') |', '*' * stars_to_print
+
+# Delete the sensor object
+del sensor