diff --git a/Makefile b/Makefile
index 1304894..eba91c9 100644
--- a/Makefile
+++ b/Makefile
@@ -6,9 +6,9 @@
 	freeze-nrf-vendor-deps \
 	lint
 
-NRF_DFU_PORT ?= /dev/ttyUSB0
-NRF_DFU_BAUD ?= 115200
-NRF_DFU_DELAY ?= 1.5
+AMPY_PORT ?= /dev/ttyUSB0
+AMPY_BAUD ?= 115200
+AMPY_DELAY ?= 1.5
 ARDUINO ?= /usr/share/arduino
 
 devdeps: Pipfile.lock
@@ -39,8 +39,8 @@ circuitpy-deps: .circuitpy-deps
 micropython-deps: .micropython-deps
 
 freeze-nrf-vendor-deps: vendor/circuitpython/ports/nrf/freeze/.kmk_frozen
-
 freeze-teensy3.1-vendor-deps: vendor/micropython/ports/teensy/freeze/.kmk_frozen
+freeze-stm32-vendor-deps: vendor/micropython/ports/stm32/freeze/.kmk_frozen
 
 vendor/circuitpython/ports/nrf/freeze/.kmk_frozen: upy-freeze.txt
 	@echo "===> Preparing vendored dependencies for bundling"
@@ -55,6 +55,13 @@ vendor/micropython/ports/teensy/freeze/.kmk_frozen: upy-freeze.txt
 	@cat $< | xargs -I '{}' cp -a {} vendor/micropython/ports/teensy/freeze/
 	@touch $@
 
+vendor/micropython/ports/stm32/freeze/.kmk_frozen: upy-freeze.txt
+	@echo "===> Preparing vendored dependencies for bundling"
+	@mkdir vendor/micropython/ports/stm32/freeze/
+	@rm -rf vendor/micropython/ports/stm32/freeze/*
+	@cat $< | xargs -I '{}' cp -a {} vendor/micropython/ports/stm32/freeze/
+	@touch $@
+
 circuitpy-freeze-kmk-nrf: freeze-nrf-vendor-deps
 	@echo "===> Preparing KMK source for bundling into CircuitPython"
 	@rm -rf vendor/circuitpython/ports/nrf/kmk*
@@ -65,19 +72,38 @@ micropython-freeze-kmk-teensy3.1: freeze-teensy3.1-vendor-deps
 	@rm -rf vendor/micropython/ports/teensy/kmk*
 	@cp -av kmk vendor/micropython/ports/teensy/memzip_files/
 
+micropython-freeze-kmk-stm32: freeze-stm32-vendor-deps
+	@echo "===> Preparing KMK source for bundling into MicroPython"
+	@rm -rf vendor/micropython/ports/stm32/freeze/kmk*
+	@cp -av kmk vendor/micropython/ports/stm32/freeze/
+
 circuitpy-flash-nrf:
 	@echo "===> Building and flashing CircuitPython with KMK and your keymap"
-	@make -C vendor/circuitpython/ports/nrf BOARD=feather_nrf52832 SERIAL=${NRF_DFU_PORT} SD=s132 FROZEN_MPY_DIR=freeze clean dfu-gen dfu-flash
+	@make -C vendor/circuitpython/ports/nrf BOARD=feather_nrf52832 SERIAL=${AMPY_PORT} SD=s132 FROZEN_MPY_DIR=freeze clean dfu-gen dfu-flash
 
 micropython-flash-teensy3.1:
 	@cp entrypoints/teensy31.py vendor/micropython/ports/teensy/memzip_files/main.py
 	@make -C vendor/micropython/ports/teensy/ BOARD=TEENSY_3.1 deploy
 
+micropython-flash-pyboard:
+	@make -j4 -C vendor/micropython/ports/stm32/ BOARD=PYBV11 clean
+	@make -j4 -C vendor/micropython/ports/stm32/ BOARD=PYBV11 FROZEN_MPY_DIR=freeze deploy
+
+micropython-flash-pyboard-entrypoint:
+	@echo "===> Flashing entrypoints if they doesn't already exist"
+	@sleep 4
+	@-timeout -k 5s 10s pipenv run ampy -p ${AMPY_PORT} -d ${AMPY_DELAY} -b ${AMPY_BAUD} rm /flash/main.py 2>/dev/null
+	@-timeout -k 5s 10s pipenv run ampy -p ${AMPY_PORT} -d ${AMPY_DELAY} -b ${AMPY_BAUD} rm /flash/boot.py 2>/dev/null
+	@-timeout -k 5s 10s pipenv run ampy -p ${AMPY_PORT} -d ${AMPY_DELAY} -b ${AMPY_BAUD} put entrypoints/pyboard.py /flash/main.py
+	@-timeout -k 5s 10s pipenv run ampy -p ${AMPY_PORT} -d ${AMPY_DELAY} -b ${AMPY_BAUD} put entrypoints/pyboard_boot.py /flash/boot.py
+	@-timeout -k 5s 10s pipenv run ampy -p ${AMPY_PORT} -d ${AMPY_DELAY} -b ${AMPY_BAUD} reset
+	@echo "===> Flashed keyboard successfully!"
+
 circuitpy-flash-nrf-entrypoint:
 	@echo "===> Flashing entrypoint if it doesn't already exist"
 	@sleep 2
-	@-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
+	@-timeout -k 5s 10s pipenv run ampy -p ${AMPY_PORT} -d ${AMPY_DELAY} -b ${AMPY_BAUD} rm main.py 2>/dev/null
+	@-timeout -k 5s 10s pipenv run ampy -p ${AMPY_PORT} -d ${AMPY_DELAY} -b ${AMPY_BAUD} put entrypoints/feather_nrf52832.py main.py
 	@echo "===> Flashed keyboard successfully!"
 
 ifndef BOARD
@@ -100,6 +126,16 @@ build-teensy-3.1: lint devdeps micropython-deps micropython-freeze-kmk-teensy3.1
 	@$(MAKE) ARDUINO=${ARDUINO} micropython-flash-teensy3.1
 endif
 
+ifndef BOARD
+build-pyboard:
+	@echo "===> Must provide a board (usually from boards/...) to build!"
+else
+build-pyboard: lint devdeps micropython-deps micropython-freeze-kmk-stm32
+	@echo "===> Preparing keyboard script for bundling into MicroPython"
+	@cp -av ${BOARD} vendor/micropython/ports/stm32/freeze/kmk_keyboard_user.py
+	@$(MAKE) AMPY_PORT=/dev/ttyACM0 AMPY_BAUD=115200 micropython-flash-pyboard micropython-flash-pyboard-entrypoint
+endif
+
 # Fully wipe the board with only stock CircuitPython
 burn-it-all-with-fire: lint devdeps
 	@echo "===> Flashing STOCK CircuitPython with no KMK or user keyboard scripts, and wiping entrypoint"
@@ -117,5 +153,5 @@ burn-it-all-with-fire: lint devdeps
 	@$(MAKE) circuitpy-flash-nrf
 	@echo "===> Wiping keyboard config"
 	@sleep 2
-	@-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 ${AMPY_PORT} -d ${AMPY_DELAY} -b ${AMPY_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/threethree_matrix_pyboard.py b/boards/klardotsh/threethree_matrix_pyboard.py
new file mode 100644
index 0000000..d0b767b
--- /dev/null
+++ b/boards/klardotsh/threethree_matrix_pyboard.py
@@ -0,0 +1,27 @@
+from logging import DEBUG
+
+from kmk.common.consts import DiodeOrientation
+from kmk.firmware import Firmware
+
+
+def main():
+    cols = ('X10', 'X11', 'X12')
+    rows = ('X1', 'X2', 'X3')
+
+    diode_orientation = DiodeOrientation.COLUMNS
+
+    keymap = [
+        ['A', 'B', 'C'],
+        ['D', 'E', 'F'],
+        ['G', 'H', 'I'],
+    ]
+
+    firmware = Firmware(
+        keymap=keymap,
+        row_pins=rows,
+        col_pins=cols,
+        diode_orientation=diode_orientation,
+        log_level=DEBUG,
+    )
+
+    firmware.go()
diff --git a/entrypoints/pyboard.py b/entrypoints/pyboard.py
new file mode 100644
index 0000000..31df713
--- /dev/null
+++ b/entrypoints/pyboard.py
@@ -0,0 +1,10 @@
+import sys
+
+from kmk_keyboard_user import main
+
+if __name__ == '__main__':
+    try:
+        main()
+    except Exception as e:
+        sys.print_exception(e)
+        sys.exit(1)
diff --git a/entrypoints/pyboard_boot.py b/entrypoints/pyboard_boot.py
new file mode 100644
index 0000000..46695ae
--- /dev/null
+++ b/entrypoints/pyboard_boot.py
@@ -0,0 +1,3 @@
+import pyb
+
+pyb.usb_mode('VCP+HID')  # act as a serial device and a mouse
diff --git a/kmk/micropython/matrix.py b/kmk/micropython/matrix.py
new file mode 100644
index 0000000..e7c329b
--- /dev/null
+++ b/kmk/micropython/matrix.py
@@ -0,0 +1,49 @@
+import machine
+
+from kmk.common.abstract.matrix_scanner import AbstractMatrixScanner
+from kmk.common.consts import DiodeOrientation
+
+
+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
+        unique_pins = set(cols) | set(rows)
+        if len(unique_pins) != len(cols) + len(rows):
+            raise ValueError('Cannot use a pin as both a column and row')
+
+        self.cols = [machine.Pin(pin) for pin in cols]
+        self.rows = [machine.Pin(pin) for pin in rows]
+        self.diode_orientation = diode_orientation
+
+        if self.diode_orientation == DiodeOrientation.COLUMNS:
+            self.outputs = self.cols
+            self.inputs = self.rows
+        elif self.diode_orientation == DiodeOrientation.ROWS:
+            self.outputs = self.rows
+            self.inputs = self.cols
+        else:
+            raise ValueError('Invalid DiodeOrientation: {}'.format(
+                self.diode_orientation,
+            ))
+
+        for pin in self.outputs:
+            pin.init(machine.Pin.OUT)
+            pin.off()
+
+        for pin in self.inputs:
+            pin.init(machine.Pin.IN, machine.Pin.PULL_DOWN)
+            pin.off()
+
+    def _normalize_matrix(self, matrix):
+        return super()._normalize_matrix(matrix)
+
+    def raw_scan(self):
+        matrix = []
+
+        for opin in self.outputs:
+            opin.value(1)
+            matrix.append([bool(ipin.value()) for ipin in self.inputs])
+            opin.value(0)
+
+        return self._normalize_matrix(matrix)
diff --git a/setup.cfg b/setup.cfg
index 76c6b0c..02f98c8 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -3,4 +3,4 @@ exclude = .git,__pycache__,vendor,.venv
 max_line_length = 99
 
 [isort]
-known_third_party = analogio,bitbangio,bleio,board,busio,digitalio,framebuf,gamepad,gc,microcontroller,micropython,pulseio,pyb,pydux,uio,ubluepy
+known_third_party = analogio,bitbangio,bleio,board,busio,digitalio,framebuf,gamepad,gc,microcontroller,micropython,pulseio,pyb,pydux,uio,ubluepy,machine,pyb