diff --git a/Makefile b/Makefile
index fb9f393..c114676 100644
--- a/Makefile
+++ b/Makefile
@@ -6,6 +6,10 @@
 	freeze-nrf-vendor-deps \
 	lint
 
+NRF_DFU_PORT ?= /dev/ttyUSB0
+NRF_DFU_BAUD ?= 115200
+NRF_DFU_DELAY ?= 1.5
+
 devdeps: Pipfile.lock
 	@pipenv install --dev --ignore-pipfile
 
@@ -39,15 +43,15 @@ circuitpy-freeze-kmk-nrf: freeze-nrf-vendor-deps
 	@rm -rf vendor/circuitpython/ports/nrf/kmk*
 	@cp -av kmk vendor/circuitpython/ports/nrf/freeze/
 
-circuitpy-flash-nrf: circuitpy-freeze-kmk-nrf
+circuitpy-flash-nrf:
 	@echo "===> Building and flashing CircuitPython with KMK and your keymap"
-	@make -C vendor/circuitpython/ports/nrf BOARD=feather_nrf52832 SERIAL=/dev/ttyUSB0 SD=s132 FROZEN_MPY_DIR=freeze clean dfu-gen dfu-flash
+	@make -C vendor/circuitpython/ports/nrf BOARD=feather_nrf52832 SERIAL=${NRF_DFU_PORT} SD=s132 FROZEN_MPY_DIR=freeze clean dfu-gen dfu-flash
 
 circuitpy-flash-nrf-entrypoint:
 	@echo "===> Flashing entrypoint if it doesn't already exist"
 	@sleep 2
-	@-timeout -k 5s 10s pipenv run ampy rm main.py 2>/dev/null
-	@-timeout -k 5s 10s pipenv run ampy put entrypoints/feather_nrf52832.py main.py
+	@-timeout -k 5s 10s pipenv run ampy -p ${NRF_DFU_PORT} -d ${NRF_DFU_DELAY} -b ${NRF_DFU_BAUD} rm main.py 2>/dev/null
+	@-timeout -k 5s 10s pipenv run ampy -p ${NRF_DFU_PORT} -d ${NRF_DFU_DELAY} -b ${NRF_DFU_BAUD} put entrypoints/feather_nrf52832.py main.py
 	@echo "===> Flashed keyboard successfully!"
 
 build-feather-test: lint devdeps circuitpy-deps circuitpy-freeze-kmk-nrf
@@ -77,5 +81,5 @@ burn-it-all-with-fire: lint devdeps
 	@$(MAKE) circuitpy-flash-nrf
 	@echo "===> Wiping keyboard config"
 	@sleep 2
-	@-pipenv run ampy rm main.py 2>/dev/null
+	@-timeout -k 5s 10s pipenv run ampy -p ${NRF_DFU_PORT} -d ${NRF_DFU_DELAY} -b ${NRF_DFU_BAUD} rm main.py 2>/dev/null
 	@echo "===> Wiped! Probably safe to flash keyboard, try Python serial REPL to verify?"
diff --git a/boards/klardotsh/twotwo_matrix_feather.py b/boards/klardotsh/twotwo_matrix_feather.py
index e8b23eb..84c9cb8 100644
--- a/boards/klardotsh/twotwo_matrix_feather.py
+++ b/boards/klardotsh/twotwo_matrix_feather.py
@@ -1,23 +1,25 @@
 import board
 
-from kmk.circuitpython.matrix import MatrixScanner
 from kmk.common.consts import DiodeOrientation
-from kmk.common.keymap import Keymap
+from kmk.firmware import Firmware
 
 
 def main():
     cols = (board.A4, board.A5)
     rows = (board.D27, board.A6)
 
-    matrix = MatrixScanner(
-        cols=cols, rows=rows,
-        diode_orientation=DiodeOrientation.COLUMNS,
-    )
+    diode_orientation = DiodeOrientation.COLUMNS
 
-    keymap = Keymap([
+    keymap = [
         ['A', 'B'],
         ['C', 'D'],
-    ])
+    ]
 
-    while True:
-        keymap.parse(matrix.raw_scan())
+    firmware = Firmware(
+        keymap=keymap,
+        row_pins=rows,
+        col_pins=cols,
+        diode_orientation=diode_orientation,
+    )
+
+    firmware.go()
diff --git a/entrypoints/feather_nrf52832.py b/entrypoints/feather_nrf52832.py
index 1f52211..c07d83c 100644
--- a/entrypoints/feather_nrf52832.py
+++ b/entrypoints/feather_nrf52832.py
@@ -1,5 +1,4 @@
 from kmk_keyboard_user import main
 
-
 if __name__ == '__main__':
     main()
diff --git a/kmk/circuitpython/matrix.py b/kmk/circuitpython/matrix.py
index 5203cc2..666a2ca 100644
--- a/kmk/circuitpython/matrix.py
+++ b/kmk/circuitpython/matrix.py
@@ -1,9 +1,10 @@
 import digitalio
 
+from kmk.common.abstract.matrix_scanner import AbstractMatrixScanner
 from kmk.common.consts import DiodeOrientation
 
 
-class MatrixScanner:
+class MatrixScanner(AbstractMatrixScanner):
     def __init__(self, cols, rows, diode_orientation=DiodeOrientation.COLUMNS):
         # A pin cannot be both a row and column, detect this by combining the
         # two tuples into a set and validating that the length did not drop
@@ -35,20 +36,7 @@ class MatrixScanner:
             pin.switch_to_input(pull=digitalio.Pull.DOWN)
 
     def _normalize_matrix(self, matrix):
-        '''
-        We always want to internally look at a keyboard as a list of rows,
-        where a "row" is a list of keycodes (columns).
-
-        This will convert DiodeOrientation.COLUMNS matrix scans into a
-        ROWS scan, so we never have to think about these things again.
-        '''
-        if self.diode_orientation == DiodeOrientation.ROWS:
-            return matrix
-
-        return [
-            [col[col_entry] for col in matrix]
-            for col_entry in range(max(len(col) for col in matrix))
-        ]
+        return super()._normalize_matrix(matrix)
 
     def raw_scan(self):
         matrix = []
diff --git a/kmk/circuitpython/util.py b/kmk/circuitpython/util.py
index 01d63d5..0b822b1 100644
--- a/kmk/circuitpython/util.py
+++ b/kmk/circuitpython/util.py
@@ -1,7 +1,8 @@
+import sys
+import time
+
 import board
 import digitalio
-import time
-import sys
 
 
 def feather_signal_error_with_led_flash(rate=0.5):
diff --git a/kmk/common/abstract/__init__.py b/kmk/common/abstract/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/kmk/common/abstract/matrix_scanner.py b/kmk/common/abstract/matrix_scanner.py
new file mode 100644
index 0000000..4ef71dc
--- /dev/null
+++ b/kmk/common/abstract/matrix_scanner.py
@@ -0,0 +1,25 @@
+from kmk.common.consts import DiodeOrientation
+
+
+class AbstractMatrixScanner():
+    def __init__(self, cols, rows, diode_orientation=DiodeOrientation.COLUMNS):
+        raise NotImplementedError('Abstract implementation')
+
+    def _normalize_matrix(self, matrix):
+        '''
+        We always want to internally look at a keyboard as a list of rows,
+        where a "row" is a list of keycodes (columns).
+
+        This will convert DiodeOrientation.COLUMNS matrix scans into a
+        ROWS scan, so we never have to think about these things again.
+        '''
+        if self.diode_orientation == DiodeOrientation.ROWS:
+            return matrix
+
+        return [
+            [col[col_entry] for col in matrix]
+            for col_entry in range(max(len(col) for col in matrix))
+        ]
+
+    def raw_scan(self):
+        raise NotImplementedError('Abstract implementation')
diff --git a/kmk/common/keymap.py b/kmk/common/keymap.py
index cdcfc9c..815c082 100644
--- a/kmk/common/keymap.py
+++ b/kmk/common/keymap.py
@@ -10,9 +10,9 @@ class Keymap:
         for ridx, row in enumerate(matrix):
             for cidx, col in enumerate(row):
                 if col != self.state[ridx][cidx]:
-                    print('{}: {}'.format(
+                    yield '{}: {}'.format(
                         'KEYDOWN' if col else 'KEYUP',
                         self.map[ridx][cidx],
-                    ))
+                    )
 
         self.state = matrix
diff --git a/kmk/firmware.py b/kmk/firmware.py
new file mode 100644
index 0000000..7e5fa22
--- /dev/null
+++ b/kmk/firmware.py
@@ -0,0 +1,18 @@
+from kmk.common.keymap import Keymap
+
+try:
+    from kmk.circuitpython.matrix import MatrixScanner
+except ImportError:
+    from kmk.micropython.matrix import MatrixScanner
+
+
+class Firmware:
+    def __init__(self, keymap, row_pins, col_pins, diode_orientation):
+        self.raw_keymap = keymap
+        self.keymap = Keymap(keymap)
+        self.matrix = MatrixScanner(col_pins, row_pins, diode_orientation)
+
+    def go(self):
+        while True:
+            for event in self.keymap.parse(self.matrix.raw_scan()):
+                print(event)