configurable address

Author: michaellee1019

README.md

@@ -2,7 +2,11 @@
 A Viam module that returns sensor values from a capacitive touch sensor device with the MPR121 chip.
 
 # Attributes
-No configuration attributes are required. The module is built assuming the default I2C bus.
+No configuration attributes are required if your device operates on the i2c address of `0x5A`. Otherwise you can configure a different address using the config example below. The module is built assuming the default I2C bus.
+
+{
+  "i2c_address": "0x5A"
+}
 
 # GetReadings
 The Sensor.GetReadings response will look like the following. A touchpads array contains the status of each pad/input to the device. True means that it is being touched, false means untouched. In the below example, input 0 is touched and 1-11 is untouched.

models.py

@@ -25,7 +25,12 @@ def reconfigure(self,
                     config: ComponentConfig,
                     dependencies: Mapping[ResourceName, ResourceBase]):
         i2c = busio.I2C(board.SCL, board.SDA)
-        self.mpr121 = adafruit_mpr121.MPR121(i2c)
+
+        i2c_address: int = 0x5A
+        if "i2c_address" in config.attributes.fields:
+            i2c_address = int(config.attributes.fields["i2c_address"].string_value, base=16)
+
+        self.mpr121 = adafruit_mpr121.MPR121(i2c=i2c, address=i2c_address)
 
     async def get_readings(self, **kwargs):
         return {"touchpads": [t.value for t in self.mpr121]}

setup.sh

@@ -28,6 +28,7 @@ source .env
 if [ -f $VIRTUAL_ENV/.install_complete ]; then
 	echo "completion marker is present, skipping virtualenv setup"
 else
+	sudo apt install -y git
 	echo creating virtualenv at $VIRTUAL_ENV
 	python3 -m venv $VIRTUAL_ENV
 	echo installing dependencies from requirements.txt