By tpm | March 7, 2017
A few weeks back, I added my review of the TI-Innovator. I had a couple of demos in that review, and I’ve been adding an explanation and code so interested teachers and students can try them out in their own classrooms. In this post, I’m taking the TI-Innovator Ranger for a spin. The Ranger technology is nothing new for Texas Instruments calculators, going all the way back to the TI-83 family of devices. A simple explanation of the Ranger is that it sense out a pulse of sound and then measures how that sound bounces back to see how close the nearest object located in front of it is, much like sonar.
In the past, Texas Instruments has provided apps and programs to use on TI devices that work with the Ranger to have your graphing calculator generate plots like distance vs. time or velocity vs. time. I’ve used this in my classes from middle school through high school to discuss concepts like rates of change.
There are some importance differences with the TI-Innovator Ranger. First, it is a much smaller device that connects to the the Innovator Hub. Second, the expectation is that a user will write their own program to use its measurements rather than one provided by Texas Instruments. That’s exactly what I’ve done in this demo video. Rather than create a distance vs. time plot, I’ve used the speaker in the TI-Innovator Hub to give audio feedback. Here’s the video:
How did I accomplish this? In fact it took only about 10 lines of code to get this type of response from the Innovator, all of which would be appropriate for an Algebra I class. Essentially, I had the TI-Nspire get a reading of the distance, d, detected by the ranger. Then, I had a very simple linear function that took that distance and created a new variable, f, larger (higher) for small distances and smaller (lower) for larger distances. The Hub is then instructed to play a brief tone of that frequency. To make this behavior repeat for a while, I wrapped it in a For loop that iterates 200 times.
Define rngalm()= Prgm Define d=0 Send "CONNECT RANGER 1 TO IN 1 " For n,1,200 Send "READ RANGER 1" Get d Define f=1000-d*300 Send "SET SOUND eval(f) TIME .1" Disp d EndFor EndPrgm
Again, I think all that given a little time to break this into its components, all of this could be understood by a 14 year old as one of her first exposures to programming. This is what makes the TI-Innovator an attractive device in the mathematics or science classroom, its ability to combine simple math and science concepts with coding.