DM: add blinka thermal cam example

Author: deanm1278

examples/thermalcam.py

@@ -0,0 +1,88 @@
+import os
+import math
+import time
+
+import busio
+import board
+
+import pygame
+import numpy as np
+from scipy.interpolate import griddata
+
+from colour import Color
+
+import adafruit_amg88xx
+
+i2c_bus = busio.I2C(board.SCL, board.SDA)
+
+#low range of the sensor (this will be blue on the screen)
+MINTEMP = 26.
+
+#high range of the sensor (this will be red on the screen)
+MAXTEMP = 32.
+
+#how many color values we can have
+COLORDEPTH = 1024
+
+os.putenv('SDL_FBDEV', '/dev/fb1')
+pygame.init()
+
+#initialize the sensor
+sensor = adafruit_amg88xx.AMG88XX(i2c_bus)
+
+points = [(math.floor(ix / 8), (ix % 8)) for ix in range(0, 64)]
+grid_x, grid_y = np.mgrid[0:7:32j, 0:7:32j]
+
+#sensor is an 8x8 grid so lets do a square
+height = 240
+width = 240
+
+#the list of colors we can choose from
+blue = Color("indigo")
+colors = list(blue.range_to(Color("red"), COLORDEPTH))
+
+#create the array of colors
+colors = [(int(c.red * 255), int(c.green * 255), int(c.blue * 255)) for c in colors]
+
+displayPixelWidth = width / 30
+displayPixelHeight = height / 30
+
+lcd = pygame.display.set_mode((width, height))
+
+lcd.fill((255, 0, 0))
+
+pygame.display.update()
+pygame.mouse.set_visible(False)
+
+lcd.fill((0, 0, 0))
+pygame.display.update()
+
+#some utility functions
+def constrain(val, min_val, max_val):
+    return min(max_val, max(min_val, val))
+
+def map_value(x, in_min, in_max, out_min, out_max):
+  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min
+
+#let the sensor initialize
+time.sleep(.1)
+    
+while True:
+
+    #read the pixels
+    pixels = []
+    for row in sensor.pixels:
+        pixels = pixels + row
+    pixels = [map_value(p, MINTEMP, MAXTEMP, 0, COLORDEPTH - 1) for p in pixels]
+    
+    #perform interpolation
+    bicubic = griddata(points, pixels, (grid_x, grid_y), method='cubic')
+
+    #draw everything
+    for ix, row in enumerate(bicubic):
+        for jx, pixel in enumerate(row):
+            pygame.draw.rect(lcd, colors[constrain(int(pixel), 0, COLORDEPTH- 1)], 
+                            (displayPixelHeight * ix, displayPixelWidth * jx, displayPixelHeight, displayPixelWidth))
+    
+    pygame.display.update()
+