diff --git a/.github/workflows/sim.yml b/.github/workflows/sim.yml
new file mode 100644
index 0000000..03c9791
--- /dev/null
+++ b/.github/workflows/sim.yml
@@ -0,0 +1,44 @@
+name: wasp-os simulator tests
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-20.04
+
+    steps:
+    - name: Checkout files
+      id:   checkout-files
+      uses: actions/checkout@v2
+
+    - name: Check the cached python downloads
+      id:   cache-modules
+      uses: actions/cache@v2
+      env:
+        cache-name: cache-toolchain
+      with:
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-pip-${{ hashFiles('wasp/requirements.txt') }}
+        restore-keys: ${{ runner.os }}-pip-${{ hashFiles('wasp/requirements.txt') }}
+
+    - name: Install packages
+      id: install-packages
+      run: |
+        sudo apt-get update
+        sudo apt-get install libsdl2-2.0.0
+
+    - name: Install python modules
+      id:   install-modules
+      run: |
+          pip3 install -r wasp/requirements.txt
+
+    - name: Run the simulator tests
+      id:   run-tests
+      run:  |
+          PYTEST=$HOME/.local/bin/pytest \
+          SDL_VIDEODRIVER=dummy \
+          make check
diff --git a/Makefile b/Makefile
index 470de25..0a1a517 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,8 @@
 export PYTHONPATH := $(PWD)/tools/nrfutil:$(PWD)/tools/intelhex:$(PYTHONPATH)
 
+PYTHON ?= python3
+PYTEST ?= pytest-3
+
 all : bootloader reloader micropython
 
 # If BOARD is undefined then set it up so that expanding it issues an
@@ -33,13 +36,13 @@ submodules :
 bootloader: build-$(BOARD_SAFE)
 	$(RM) bootloader/_build-$(BOARD)_nrf52832//$(BOARD)_nrf52832_bootloader-*-nosd.hex
 	$(MAKE) -C bootloader/ BOARD=$(BOARD)_nrf52832 all genhex
-	python3 tools/hexmerge.py \
+	$(PYTHON) tools/hexmerge.py \
 		bootloader/_build-$(BOARD)_nrf52832/$(BOARD)_nrf52832_bootloader-*-nosd.hex \
 		bootloader/lib/softdevice/s132_nrf52_6.1.1/s132_nrf52_6.1.1_softdevice.hex \
 		-o build-$(BOARD)/bootloader.hex
-	python3 tools/hex2c.py build-$(BOARD)/bootloader.hex > \
+	$(PYTHON) tools/hex2c.py build-$(BOARD)/bootloader.hex > \
 		reloader/src/boards/$(BOARD)/bootloader.h
-	python3 -m nordicsemi dfu genpkg \
+	$(PYTHON) -m nordicsemi dfu genpkg \
 		--bootloader bootloader/_build-$(BOARD)_nrf52832//$(BOARD)_nrf52832_bootloader-*-nosd.hex \
 		--softdevice bootloader/lib/softdevice/s132_nrf52_6.1.1/s132_nrf52_6.1.1_softdevice.hex \
 		build-$(BOARD)/bootloader-daflasher.zip
@@ -63,7 +66,7 @@ micropython: build-$(BOARD_SAFE) wasp/boards/$(BOARD_SAFE)/watch.py
 		MICROPY_VFS_LFS2=1 \
 		FROZEN_MANIFEST=$(PWD)/wasp/boards/$(BOARD)/manifest.py \
 		USER_C_MODULES=$(PWD)/wasp/modules
-	python3 -m nordicsemi dfu genpkg \
+	$(PYTHON) -m nordicsemi dfu genpkg \
 		--dev-type 0x0052 \
 		--application micropython/ports/nrf/build-$(BOARD)-s132/firmware.hex \
 		build-$(BOARD)/micropython.zip
@@ -72,7 +75,7 @@ build-$(BOARD_SAFE):
 	mkdir -p build-$(BOARD)
 
 dfu:
-	python3 -m nordicsemi dfu serial --package micropython.zip --port /dev/ttyACM0
+	$(PYTHON) -m nordicsemi dfu serial --package micropython.zip --port /dev/ttyACM0
 
 flash:
 	pyocd erase -t nrf52 --mass
@@ -93,7 +96,12 @@ docs:
 
 sim:
 	PYTHONDONTWRITEBYTECODE=1 PYTHONPATH=.:wasp/boards/simulator:wasp \
-	python3 -i wasp/boards/simulator/main.py
+	$(PYTHON) -i wasp/boards/simulator/main.py
+
+check:
+	PYTHONDONTWRITEBYTECODE=1 PYTHONPATH=.:wasp/boards/simulator:wasp \
+	$(PYTEST) -v -W ignore wasp/boards/simulator
+
 
 .PHONY: bootloader reloader docs micropython
 
diff --git a/docs/install.rst b/docs/install.rst
index 4b8b7a4..68fc0f7 100644
--- a/docs/install.rst
+++ b/docs/install.rst
@@ -36,7 +36,7 @@ with pip instead:
 
 .. code-block:: sh
 
-    pip3 install --user cbor click numpy pexpect Pillow pyserial pysdl2
+    pip3 install --user -r wasp/requirements.txt
 
 You will also need a toolchain for the Arm Cortex-M4. wasp-os is developed and
 tested using the `GNU-RM toolchain
diff --git a/wasp/boards/simulator/test_smoke.py b/wasp/boards/simulator/test_smoke.py
new file mode 100644
index 0000000..6dd2757
--- /dev/null
+++ b/wasp/boards/simulator/test_smoke.py
@@ -0,0 +1,64 @@
+import pytest
+import time
+import wasp
+
+def step():
+    wasp.system._tick()
+    wasp.machine.deepsleep()
+wasp.system.step = step
+
+def play(appname):
+    system = wasp.system
+    system.switch(system.apps[appname])
+    for i in range(4):
+        system.step()
+        time.sleep(0.125)
+    system.switch(system.quick_ring[0])
+wasp.system.play = play
+
+wasp.system.apps = {}
+for app in wasp.system.quick_ring + wasp.system.launcher_ring:
+    wasp.system.apps[app.NAME] = app
+
+@pytest.fixture
+def system():
+    system = wasp.system
+    if system.app != system.quick_ring[0]:
+        system.switch(system.quick_ring[0])
+    system.step()
+
+    return system
+
+def test_step(system):
+    system.step()
+
+def test_quick_ring(system):
+    names = [ x.NAME for x in system.quick_ring ]
+    assert('Clock' in names)
+    assert('Steps' in names)
+    assert('Timer' in names)
+    assert('Heart' in names)
+
+def test_launcher_ring(system):
+    names = [ x.NAME for x in system.launcher_ring ]
+    assert('Self Test' in names)
+    assert('Settings' in names)
+    assert('Torch' in names)
+
+def test_steps(system):
+    system.play('Steps')
+
+def test_timer(system):
+    system.play('Timer')
+
+def test_heart(system):
+    system.play('Heart')
+
+def test_self_test(system):
+    system.play('Self Test')
+
+def test_settings(system):
+    system.play('Settings')
+
+def test_torch(system):
+    system.play('Torch')
diff --git a/wasp/requirements.txt b/wasp/requirements.txt
new file mode 100644
index 0000000..e64a397
--- /dev/null
+++ b/wasp/requirements.txt
@@ -0,0 +1,8 @@
+cbor
+click
+numpy
+pexpect
+Pillow
+pyserial
+pysdl2
+pytest