Additional examples for specific h/w by our interns (#171)

adc/microphone_adc - Read analog values from a microphone and plot the measured sound amplitude.
i2c/bmp280_i2c - Read and convert temperature and pressure data from a BMP280 sensor, attached to an I2C bus.
i2c/lis3dh_i2c - Read acceleration and temperature value from a LIS3DH sensor via I2C
i2c/mcp9808_i2c - Read temperature, set limits and raise alerts when limits are surpassed.
i2c/mma8451_i2c - Read acceleration from a MMA8451 accelerometer and set range and precision for the data.
i2c/mpl3115a2_i2c - Interface with an MPL3115A2 altimeter, exploring interrupts and advanced board features, via I2C.
i2c/oled_i2c - Convert and display a bitmap on a 128x32 SSD1306-driven OLED display
i2c/pa1010d_i2c - Read GPS location data, parse and display data via I2C.
i2c/pcf8523_i2c - Read time and date values from a real time clock. Set current time and alarms on it.
uart/lcd_uart - Display text and symbols on a 16x02 RGB LCD display via UART

i2c/oled_i2c/img_to_array.py

@@ -0,0 +1,81 @@
+#!/usr/bin/env python3
+
+# Converts a grayscale image into a format able to be
+# displayed by the SSD1306 driver in horizontal addressing mode
+
+# usage: python3 img_to_array.py <logo.bmp>
+
+# depends on the Pillow library
+# `python3 -m pip install --upgrade Pillow`
+
+from PIL import Image
+import sys
+from pathlib import Path
+
+OLED_HEIGHT = 32
+OLED_WIDTH = 128
+OLED_PAGE_HEIGHT = 8
+
+if len(sys.argv) < 2:
+    print("No image path provided.")
+    sys.exit()
+
+img_path = sys.argv[1]
+
+try:
+    im = Image.open(img_path)
+except OSError:
+    raise Exception("Oops! The image could not be opened.")
+
+img_width = im.size[0]
+img_height = im.size[1]
+
+if img_width > OLED_WIDTH or img_height > OLED_HEIGHT:
+    print(f'Your image is f{img_width} pixels wide and {img_height} pixels high, but...')
+    raise Exception(f"OLED display only {OLED_WIDTH} pixels wide and {OLED_HEIGHT} pixels high!")
+
+if not (im.mode == "1" or im.mode == "L"):
+    raise Exception("Image must be grayscale only")
+
+# black or white
+out = im.convert("1")
+
+img_name = Path(im.filename).stem
+
+# `pixels` is a flattened array with the top left pixel at index 0
+# and bottom right pixel at the width*height-1
+pixels = list(out.getdata())
+
+# swap white for black and swap (255, 0) for (1, 0)
+pixels = [0 if x == 255 else 1 for x in pixels]
+
+# our goal is to divide the image into 8-pixel high pages
+# and turn a pixel column into one byte, eg for one page:
+# 0 1 0 ....
+# 1 0 0
+# 1 1 1
+# 0 0 1
+# 1 1 0
+# 0 1 0
+# 1 1 1
+# 0 0 1 ....
+
+# we get 0x6A, 0xAE, 0x33 ... and so on
+# as `pixels` is flattened, each bit in a column is IMG_WIDTH apart from the next
+
+buffer = []
+for i in range(img_height // OLED_PAGE_HEIGHT):
+    start_index = i*img_width*OLED_PAGE_HEIGHT
+    for j in range(img_width):
+        out_byte = 0
+        for k in range(OLED_PAGE_HEIGHT):
+            out_byte |= pixels[k*img_width + start_index + j] << k
+        buffer.append(f'{out_byte:#04x}')
+
+buffer = ", ".join(buffer)
+buffer_hex = f'static uint8_t {img_name}[] = {{{buffer}}}\n'
+
+with open(f'{img_name}.h', 'wt') as file:
+    file.write(f'#define IMG_WIDTH {img_width}\n')
+    file.write(f'#define IMG_HEIGHT {img_height}\n\n')
+    file.write(buffer_hex)