diff --git a/.gitignore b/.gitignore
index 7f56f29f9788213d9279670fa2c77e0a3406952b..7bfd7fbfd74af6aa9fd8f86e6d41b13d9026db05 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,5 @@
 # ignore any virtual environment
 *venv
+
+# ignore pycache
+*__pycache__
\ No newline at end of file
diff --git a/README.md b/README.md
index 5f1c9c641e0500be5d15165164a17281366dca56..306a155be088ef759858bf9c1bf125d557b87b36 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # README
 
-# First create a python virtual environment
+## First create a python virtual environment
 
 ```bash
 python3 -m venv demo_venv
@@ -17,4 +17,11 @@ which pip
 $ ~/tiqi-js-tutorial/demo_venv/bin/pip
 which python
 $ ~/tiqi-js-tutorial/demo_venv/bin/python
+```
+
+## Create mock device class
+
+```bash
+mkdir device
+touch device/__init__.py
 ```
\ No newline at end of file
diff --git a/device/__init__.py b/device/__init__.py
new file mode 100644
index 0000000000000000000000000000000000000000..3f39f413f584813e10bc695ce16fb26d66385e13
--- /dev/null
+++ b/device/__init__.py
@@ -0,0 +1 @@
+from .device import Device
diff --git a/device/device.py b/device/device.py
new file mode 100644
index 0000000000000000000000000000000000000000..ec557c420779257d3164392a3962dcd2cba476a6
--- /dev/null
+++ b/device/device.py
@@ -0,0 +1,32 @@
+class Device:
+    __voltage = 0.0
+    __current = 0.0
+
+    def __init__(self):
+        # code to connect to device
+        self.__voltage = 1.0
+        self.__current = 0.0
+
+    def _get_voltage(self):
+        # read voltage from device
+        voltage = self.__voltage
+        return voltage
+
+    def _set_voltage(self, new_voltage):
+        # write voltage to device
+        self.__voltage = new_voltage
+
+    def _get_current(self):
+        # read current from device
+        current = self.__curent
+        return current
+
+    def _set_current(self, new_current):
+        # write current to device
+        self.__curent = new_current
+
+    def _calculate_resistance(self):
+        current = self._get_current()
+        voltage = self._get_voltage()
+        resistance = voltage / current
+        return resistance