Ponar
While at the last Maker Faire, I picked up a 4wd robot kit.
My thought is to hook an ultrasonic sensor to it, to do some simple obstacle avoidance. Since I’ve never worked with any of these components before (servo’s, ultrasonic sensors, motor-drivers, etc), I want to break down each step so I can really grasp how this stuff works.
I was looking at my bucket of parts and it dawned on me: I have a servo, I have a Ping))) sensor, a spare Arduino Uno, a bunch of Erector Set parts, and knowledge of Processing programming: I could (should!) make a simple sonar system. So the “Ponar” was born: Ping))) + Arduino + Servo + Processing = Ponar.
How it works:
The Arduino program sweeps the servo back and forth over a 90deg arc. At each degree, the Ping))) sensor returns back a distance reading. The degrees and distance values are passed over the serial port to the PC, where the Processing application turns them into a ‘traditional looking’ (in my head at least) sonar read-out.
See it in action:
Want to make one too? Here’s the steps I went through:
Parts List:
- Arduino Uno (older models should work fine)
- Paralax Ping))) sensor
- Ping))) Mounting Bracket Kit (includes the servo).
- Mini breadboard.
- Jumper wires.
- Various Erector Set parts. This is the set I had picked up.
- USB cable to connect Arduino to your ‘puter.
Software List:
- Arduino software.
- Processing software.
- The Arduino Sketch which you’ll load on your Arduino.
- The Processing Sketch which you’ll run from Processing.
Hardware setup:
- Assemble the servo, bracket, ping, and erector set into a pleasing arrangement.
- Connect the Arduino’s 5v and ground pins to the mini beadboard with the jumpers.
- Use jumpers to connect the Vin of the Ping))) and the servo to the Arduino powered row on the mini breadboard.
- Use jumpers to connect the ground of the Ping))) and the servo to the Arduino grounded row on the mini breadboard.
- Use a jumper to connect the signal line of the Ping))) to the Arduino’s digital pin 7.
- Use a jumper to connect the signal line of the servo to the Arduino’s digital pin 9.
- Connect the Arduino to the PC with the usb cable.
- Upload the Arduino sketch to the Arduino: It should start sweeping left and right.
- Run the Processing sketch: It should sample the serial stream being passed from the Arduino, and display the sonar view on-screen.
For a couple days work, it was really informative, and actually pretty fun.
Ponar sees beer
