Merge pull request #1573 from kattni/template-i2c

Adding I2C template code.

Author: kattni

CircuitPython_Templates/i2c_find_pins/code.py

@@ -0,0 +1,35 @@
+"""CircuitPython I2C possible pin-pair identifying script"""
+import board
+import busio
+from microcontroller import Pin
+
+
+def is_hardware_i2c(scl, sda):
+    try:
+        p = busio.I2C(scl, sda)
+        p.deinit()
+        return True
+    except ValueError:
+        return False
+    except RuntimeError:
+        return True
+
+
+def get_unique_pins():
+    exclude = ['NEOPIXEL', 'APA102_MOSI', 'APA102_SCK']
+    pins = [pin for pin in [
+        getattr(board, p) for p in dir(board) if p not in exclude]
+            if isinstance(pin, Pin)]
+    unique = []
+    for p in pins:
+        if p not in unique:
+            unique.append(p)
+    return unique
+
+
+for scl_pin in get_unique_pins():
+    for sda_pin in get_unique_pins():
+        if scl_pin is sda_pin:
+            continue
+        if is_hardware_i2c(scl_pin, sda_pin):
+            print("SCL pin:", scl_pin, "\t SDA pin:", sda_pin)

CircuitPython_Templates/i2c_mcp9808/code.py

@@ -0,0 +1,13 @@
+"""CircuitPython I2C MCP9808 Temperature Sensor Example"""
+import time
+import board
+import adafruit_mcp9808
+
+i2c = board.I2C()  # uses board.SCL and board.SDA
+mcp9808 = adafruit_mcp9808.MCP9808(i2c)
+
+while True:
+    temperature_celsius = mcp9808.temperature
+    temperature_fahrenheit = temperature_celsius * 9 / 5 + 32
+    print("Temperature: {:.2f} C {:.2f} F ".format(temperature_celsius, temperature_fahrenheit))
+    time.sleep(2)

CircuitPython_Templates/i2c_scan/code.py

@@ -0,0 +1,16 @@
+"""CircuitPython I2C Device Address Scan"""
+import time
+import board
+
+i2c = board.I2C()
+
+while not i2c.try_lock():
+    pass
+
+try:
+    while True:
+        print("I2C addresses found:", [hex(device_address) for device_address in i2c.scan()])
+        time.sleep(2)
+
+finally:  # unlock the i2c bus when ctrl-c'ing out of the loop
+    i2c.unlock()