initial working MCP2221

[Adafruit_Blinka-hackapet.git] / src / adafruit_blinka / microcontroller / mcp2221 / pin.py

diff --git a/src/adafruit_blinka/microcontroller/mcp2221/pin.py b/src/adafruit_blinka/microcontroller/mcp2221/pin.py
new file mode 100644 (file)
index 0000000..c66263e
--- /dev/null
+++ b/src/adafruit_blinka/microcontroller/mcp2221/pin.py
@@ -0,0 +1,74 @@
+from .mcp2221 import mcp2221
+
+class Pin:
+    """A basic Pin class for use with MCP2221."""
+
+    # pin modes
+    OUT     = 0
+    IN      = 1
+    ADC     = 2
+    DAC     = 3
+    # pin values
+    LOW     = 0
+    HIGH    = 1
+
+    def __init__(self, pin_id=None):
+        self.id = pin_id
+        self._mode = None
+
+    def init(self, mode=IN, pull=None):
+        if self.id is None:
+            raise RuntimeError("Can not init a None type pin.")
+        if mode in (Pin.IN, Pin.OUT):
+            mcp2221.gp_set_mode(self.id, mcp2221.GP_GPIO)
+            mcp2221.gpio_set_direction(self.id, mode)
+        elif mode == Pin.ADC:
+            mcp2221.gp_set_mode(self.id, mcp2221.GP_ALT0)
+            mcp2221.adc_configure()
+        elif mode == Pin.DAC:
+            mcp2221.gp_set_mode(self.id, mcp2221.GP_ALT1)
+            mcp2221.dac_configure()
+        else:
+            raise ValueError("Incorrect pin mode: {}".format(mode))
+        self._mode = mode
+
+    def value(self, val=None):
+        # Digital In / Out
+        if self._mode in (Pin.IN, Pin.OUT):
+            # digital read
+            if val is None:
+                return mcp2221.gpio_get_pin(self.id)
+            # digital write
+            elif val in (Pin.LOW, Pin.HIGH):
+                mcp2221.gpio_set_pin(self.id, val)
+            # nope
+            else:
+                raise ValueError("Invalid value for pin.")
+        # Analog In
+        elif self._mode == Pin.ADC:
+            if val is None:
+                # MCP2221 ADC is 10 bit, scale to 16 bit per CP API
+                return mcp2221.adc_read(self.id) * 64
+            else:
+                # read only
+                raise AttributeError("'AnalogIn' object has no attribute 'value'")
+        # Analog Out
+        elif self._mode == Pin.DAC:
+            if val is None:
+                # write only
+                raise AttributeError("unreadable attribute")
+            else:
+                # scale 16 bit value to MCP2221 5 bit DAC (yes 5 bit)
+                mcp2221.dac_write(self.id, val // 2048)
+        else:
+            raise RuntimeError("No action for mode {} with value {}".format(self._mode, val))
+
+
+# create pin instances for each pin
+G0 = Pin(0)
+G1 = Pin(1)
+G2 = Pin(2)
+G3 = Pin(3)
+
+SCL = Pin()
+SDA = Pin()
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