# Library for Reading a 16 Button Keypad on the Raspberry Pi

In this lesson we show you how to create a Python Class and Library that allows you to easily get user input on a Raspberry Pi from a 16 button keypad. This will allow very easy interaction with the keypad.

The Library Code which we develop in the video is presented below for your convenience:

To use this code as a library, save it in the same folder as your python programs, and save it as KPLIB.py

This is a simple demo program that calls the library above, to receive input from the keypad.

# Using an Arduino with Python LESSON 14: Model a Moving Marble in a Room Using Parameters

In this lesson we show how to model a moving marble in vPython. We show how to create an animation where the marble bounces off the left and righty walls of our virtual room. For your convenience, we include the code below:

# Using an Arduino with Python LESSON 8: Live Thermometer 3D Visual Using DHT11

In this video lesson we connect the Arduino to a DHT11 temperature and humidity sensor. We show how to wire the device up, and then how to code the Arduino. The data is passed from the Arduino to python. We then create a live 3D thermometer model that updates as the temperature changes.

On the arduino side, this is the code which we use:

Then on the python side, we use the following code:

# Improved Gesture Recognition in Python and MediaPipe

In this video lesson we show you how you can improve the accuracy of your gesture recognition program developed in the last lesson. We do this by normalizing the hand landmarks distance matrix to a standard size. By doing this, you get accurate results independent of the distance your hand is from the camera. For your convenience, I include the code below which we develop in this lesson. Enjoy!

s lesson. Enjoy!

# Using an Arduino with Python LESSON 5: Analog Voltage Meter in vPython

In this lesson we begin coding a 3D analog voltmeter model in vPython. We begin by connecting a potentiometer to an arduino to create a voltage divider. The voltage is read from the center tap of the potentiometer by the arduino, and then the arduino passes the data to python. Then, we animate the  analog voltmeter based on the readings passed from the Arduino. Enjoy!

Then this is the code we developed for the Python side.