Merge pull request #308 from adafruit/TheKitty-patch-16

Create cold.py, passed Travis

Make_It_Hot_Cold/cold.py

@@ -0,0 +1,51 @@
+import time
+from adafruit_crickit import crickit
+import board
+import neopixel
+
+print("Peltier Module Demo")
+
+pixels = neopixel.NeoPixel(board.NEOPIXEL, 10, auto_write=False)
+
+def show_value(time_val):
+    num_pixels = int(10-time_val)
+    for i in range(num_pixels):
+        pixels[i] = (10*(i+1), 0, 0)
+    for i in range(num_pixels, 10):
+        pixels[i] = (0, 0, 0)
+    pixels.show()
+    return
+
+# For signal control, we'll chat directly with seesaw
+ss = crickit.seesaw
+TMP36 = crickit.SIGNAL1  # TMP36 connected to signal port 1 & ground
+POT = crickit.SIGNAL8    # potentiometer connected to signal port 8 & ground
+
+peltier = crickit.dc_motor_2  # Drive the Peltier from Motor 2 Output
+
+while True:
+
+    voltage = ss.analog_read(TMP36) * 3.3 / 1024.0
+    tempC = (voltage - 0.5) * 100.0
+    tempF = (tempC * 9.0 / 5.0) + 32.0
+
+    cool_value = ss.analog_read(POT) / 102.30  # convert 0.0 to 10.0
+
+    # timing can be zero or can be 1 second to 10 seconds
+    # between 0 and 1 is too short a time for a Peltier module
+    if cool_value < 0.2:
+        cool_value = 0.0
+    if cool_value >= 0.2 and cool_value < 1.0:
+        cool_value = 1.0
+
+    print((tempF, cool_value))
+    show_value(cool_value)
+
+    # Peltier cannot be PWM - either off or on
+    # Use potentiometer read to set seconds b
+    if cool_value > 0:
+        peltier.throttle = 0.0     # turn off
+        time.sleep(cool_value)     # wait
+
+    peltier.throttle = 1.0         # turn on
+    time.sleep(10.0 - cool_value)  # wait