Merge pull request #5 from dglaude/patch-1

New example of mlx90640 on PyGamer

Author: jepler

examples/mlx90640_pygamer.py

@@ -0,0 +1,130 @@
+import time
+import board
+import busio
+import adafruit_mlx90640
+import displayio
+import terminalio
+from adafruit_display_text.label import Label
+
+number_of_colors = 64
+palette = displayio.Palette(number_of_colors)  # Palette with all our colors
+
+## Heatmap code inspired from: http://www.andrewnoske.com/wiki/Code_-_heatmaps_and_color_gradients
+color_A = [[0, 0, 0], [0, 0, 255], [0, 255, 255], [0, 255, 0], [255, 255, 0], \
+    [255, 0, 0], [255, 255, 255]]
+color_B = [[0, 0, 255], [0, 255, 255] , [0, 255, 0], [255, 255, 0], [255, 0, 0]]
+color_C = [[0, 0, 0], [255, 255, 255]]
+color_D = [[0, 0, 255], [255, 0, 0]]
+
+color = color_B
+NUM_COLORS = len (color)
+
+def MakeHeatMapColor():
+    for c in range(number_of_colors):
+        value = c * (NUM_COLORS-1) / (number_of_colors - 1)
+        idx1  = int(value)              # Our desired color will be after this index.
+        if idx1 == value :              # This is the corner case
+            red   = color[idx1][0]
+            green = color[idx1][1]
+            blue  = color[idx1][2]
+        else:
+            idx2  = idx1+1                  # ... and before this index (inclusive).
+            fractBetween = value - idx1     # Distance between the two indexes (0-1).
+            red   = int(round((color[idx2][0] - color[idx1][0]) * fractBetween + color[idx1][0]))
+            green = int(round((color[idx2][1] - color[idx1][1]) * fractBetween + color[idx1][1]))
+            blue  = int(round((color[idx2][2] - color[idx1][2]) * fractBetween + color[idx1][2]))
+        palette[c]= ( 0x010000 * red ) + ( 0x000100 * green ) + ( 0x000001 * blue )
+
+MakeHeatMapColor()
+
+# Bitmap for colour coded thermal value
+image_bitmap = displayio.Bitmap( 32, 24, number_of_colors )
+# Create a TileGrid using the Bitmap and Palette
+image_tile= displayio.TileGrid(image_bitmap, pixel_shader=palette)
+# Create a Group that scale 32*24 to 128*96
+image_group = displayio.Group(scale=4)
+image_group.append(image_tile)
+
+scale_bitmap = displayio.Bitmap( number_of_colors, 1, number_of_colors )
+# Create a Group Scale must be 128 divided by number_of_colors
+scale_group = displayio.Group(scale=2)
+scale_tile = displayio.TileGrid(scale_bitmap, pixel_shader=palette, x = 0, y = 60)
+scale_group.append(scale_tile)
+
+for i in range(number_of_colors):
+    scale_bitmap[i, 0] = i            # Fill the scale with the palette gradian
+
+# Create the super Group
+group = displayio.Group()
+
+min_label = Label(terminalio.FONT, max_glyphs=10, color=palette[0], x = 0, y = 110)
+max_label = Label(terminalio.FONT, max_glyphs=10, color=palette[number_of_colors-1], \
+    x = 80, y = 110)
+
+# Add all the sub-group to the SuperGroup
+group.append(image_group)
+group.append(scale_group)
+group.append(min_label)
+group.append(max_label)
+
+# Add the SuperGroup to the Display
+board.DISPLAY.show(group)
+
+mini = 0
+maxi = 0
+
+my_a1 = 20
+my_a2 = 37
+
+def temp2index(s, a1, a2):
+    b1 = 0
+    b2 = number_of_colors - 1
+
+    if s < a1:
+        r = b1
+    elif s > a2:
+        r = b2
+    else:
+        r = int( round( b1 + ( (s - a1) * (b2 - b1) / (a2 - a1) ) ) )
+    return r
+
+i2c = busio.I2C(board.SCL, board.SDA, frequency=800000)
+
+mlx = adafruit_mlx90640.MLX90640(i2c)
+print("MLX addr detected on I2C")
+print([hex(i) for i in mlx.serial_number])
+
+#mlx.refresh_rate = adafruit_mlx90640.RefreshRate.REFRESH_2_HZ
+mlx.refresh_rate = adafruit_mlx90640.RefreshRate.REFRESH_4_HZ
+
+frame = [0] * 768
+
+while True:
+    stamp = time.monotonic()
+    try:
+        mlx.getFrame(frame)
+    except ValueError:
+        # these happen, no biggie - retry
+        continue
+    print("Read 2 frames in %0.2f s" % (time.monotonic()-stamp))
+
+    mini = frame[0]             # Define a default min and max value
+    maxi = frame[0]             # Will be updated by temp2index function
+
+    for h in range(24):
+        for w in range(32):
+            t = frame[h*32 + w]
+            if t > maxi:
+                maxi = t
+            if t < mini:
+                mini = t
+            image_bitmap[w, (23-h)] = temp2index(t, my_a1, my_a2)
+
+    min_label.text="%0.2f" % (my_a1)
+
+    max_string="%0.2f" % (my_a2)
+    max_label.x=120-(5*len(max_string))      # Tricky calculation to left align
+    max_label.text=max_string
+
+    my_a1 = mini                  # Automatically change the color scale
+    my_a2 = maxi