Tag Archives: TCS230

Python with Arduino LESSON 5: Finishing our Virtual Reality Example

This Lesson finishes the work that was begun in Python with Arduino LESSON 4. In that lesson we built the circuit and programmed the arduino to measure the distance to a target and the color of the target. The program then output that data to the serial port. In today’s lesson we will use python to read that data stream, and use the data to dynamically update a virtual world we create.

You will need to start with the work in LESSON 4 to get your circuit working, and your arduino programmed up. Once you have done that, you are ready to use Python to program up your virtual world. Remember you will need to have the pyserial and the vPython libraries loaded. We showed how to install the software in Python with Arduino LESSON 2.

In the video we will go through the process step-by-step to create a virtual world. The code we end up with is posted below. You should not copy and paste the code, but just glance at it if you get stuck. In the end, you should develop your own virtual world and just use mine as a guide if you need more help.

 The video explains each line of the code.  Play around and tweak the values and see the effect on your virtual scene. Now your assignment is to take what you have learned here, and continue to expand your virtual world. Add objects to your virtual scene. Perhaps build an object for the breadboard, color sensor and arduino. I will give you several days to do this, and then when I come around for a project grade, I will want to see who has built the most impressive virtual scene. You should go well beyond the simple demonstration I have done here.

Python with Arduino LESSON 4: Expanding your Virtual World

In this lesson we will expand the virtual world we created in Python with Arduino LESSON 3. We will be creating a virtual world that will track a simple scene in the real world. In this project, the virtual world will track both the position and the color of a target in the real world. This lesson requires that you have the Python software and libraries installed, which we explained in LESSON 2.

Arduino Circuit
This is our circuit with the HC-SR04 ultrasonic sensor and the TCS230 Color Sensor

This Lesson will be a bit more involved, and I will take you through it step-by-step. I will need to break things into two parts. In today’s lesson we will cover the Arduino side. We will develop the software that will measure distance and color, and then send those numbers over the serial port. Then in tomorrows lesson, we will develop the Python software to create a really cool virtual graphic to display the data in a virtual world.

For this project you will need the HC-SR04 ultrasonic sensor, the TCS230 Color Sensor, the Arduino Microcontroller, and some male/female jumper wires to connect to the color sensor.

The Ultrasonic Sensor can be attached per the schematic below:

Ultrasonic Sensor Circuit
Simple Circuit for Measuring Distance

Detailed tutorial on using this sensor was described in Arduino LESSON 18, so we will not go through all the details of using the sensor here. Review that lesson if you need more help. Key point here is to connect it as seen in diagram above.

You will also need to connect up the Color Sensor.

Connecting the Color Sensor to the Arduino

Color Sensor Pin
Arduino Pin
S0 GND
S1 5V
S2 pin 7
S3 pin 8
OUT pin 4
VCC 5V
GND GND

Use of the color sensor was described in detail in Arduino LESSON 15.  You should be able to develop to write the software yourself based on earlier lessons to make measurements from both the Color Sensor, and Ultrasonic Sensor, but if you get stuck, you can glance at my code below. Again, it is important for you to write your own code and not copy and paste mine. Mine is just a reference if you get stuck.

The key point to notice with this code is the print statements, summarized below:

 Notice that we are printing  our color strengths and distance on one line separated by commas. It is important to note the order of the data. When we read this in Python, we will read it in as one line of text, and then we will parse it into its individual values. So, we must make note and remember the order the data is arranged in in this line.

Remember when you have your python program reading this data, you must have your serial monitor closed. For now though, run your program and look at the serial monitor to verify you are getting correct data in the expected format.

In the next Lesson, LESSON 5, we will build the Python program to create a virtual world from this data.