Predator Vision

Today I had

  1. A little Thermal Camera sitting around my office
  2. Some free time.

Therefore I now have a Thermal Camera hooked up to a Raspberry Pi.

This tutorial is really helpful.

2 Hints: The Github guy moved the folder locations. Move your Zip folder from the Downloads folder.


Joystick Line Follower

After I was done with version 1 of my claw bot, I wanted to use what I learned to take my line following robot to the next level. This involved developing a little joystick app that could switch between joystick mode and line following mode.

I first just tried to have two scroll bars to control the speed an direction of the treads, but this proved to be unsuccessful because the phone was unable to easily process two simletaneous moving fingers.

Then I simply made a circular target that controlled the speed of the motors such that when you pushed forward the bot moved forward, right, left etc. I did this by having the x axis control the speed of the left motor, y axis speed of the right motor. The key learning was that I needed to rotate the axis by 45 degrees counter clockwise so that forward direction is intuitive to the user.

Once the joystick was taken care of, I made a button to switch between the two modes. The key learning on this step is to disable any “Serial.print” commands on the arduino program so that the Serial line doesn’t get overburdened.

Overall it works pretty well – check out the video below!

Using MIT App Inventor

I recently took an Edx class about the MIT app inventor, which was pretty informative. However, I always tell students that the best way to really learn something is to use the subject in a project that you care about.

Therefore, my first app “on my own” was to make a controller for my Claw Bot. Ever since I made the claw bot, I was thinking that I really should make my own controller, so this project was a good way to knock this out.

The first thing that I needed to do was to connect my Bluetooth Mate Silver to the phone that I was going to use for control. I read that the tools for Serial Port Protocol (SPP) were included in the app inventor, and found this tutorial to be a really good starting point. Once two phones were connected, it was pretty straightforward to have my “client” phone look for my Claw Bot instead of the other phone. Once I was connected, it was downhill all the way because I already had created an Arduino program to respond to commands sent over a Serial line. See the video below to see how it turned out!

An interesting challenge was coding the buttons to respond in a way that was intuitive for the user. I did this by making active buttons green, and disabled buttons red. I like the way that it turned out, but know that this project is just the tip of the iceberg!

Fast blinking lights

It is easy to make a light orange.
It is easy to blink a light at precisely 500 hz.

If you know AVR programming, it is pretty easy to combine the two.
But it was a little bit of a test to read a button at the same time.

The key, like a good Crossfit workout, is to keep your pullup enabled.