Traffic Engineering in TK with Raspberry Pi

This week, TK students at one of my elementary sites became traffic engineers with the help of Scratch and some Raspberry Pi.

Coding and digital making in Transitional Kinder??* Indeed!

Honestly, I wasn't sure if it could be done, but the first time someone suggested to me that physical computing and Raspberry Pi was only for older kids, I took it upon myself to prove them wrong. Children will surprise you, and I'm a firm believer that when the bar is set high, and with the right supports, kids are perfectly capable of doing some pretty amazing things.

My TK physical computing plan? I decided to use Pibrellas (so we wouldn't need to worry about loose wires or who would do the wiring), pre-create the Scratch blocks that the students would need to use to program their LEDs, and set up the Raspberry Pi stations already opened to Scratch and the partially written code. Students would work in small teams of 2 or 3 and take turns dragging the pre-written blocks into the correct order to make their lights blink they way that they wanted.

I integrated this lesson into a unit on "Community Jobs" that students were already working on and started off by introducing students to traffic engineering as a community job. We talked about how engineers use coding to program traffic lights in order to manage traffic flow.

Before this lesson, students had some coding experience, having been introduced to coding concepts
already by their classroom teacher, using both Code.org lessons and the OSMO Coding kit. Building off of what they already knew about coding, I introduced Scratch and our coding goals, and we did some hands-on planning before programming on the computers:

• First, the teams organized print outs of red/yellow/green lights into the blinking sequence of their choice.
• Next, I guided the teams through putting printed out Scratch cards in the order we needed to make our lights blink one after the other. We talked about the importance of wait blocks and looked for patterns in our code.
• Finally, students were ready to get onto the Raspberry Pis and program their LEDs.
• One student suggested that if they got stuck working in Scratch they should use the plan that they had just created with the printed blocks to help them (score!).
•  At their stations, the teams were introduced to the Raspberry Pi computers (with Pibrellas already attached); we were lucky enough to have 4 adults in the room between classroom teacher, aid and coaches, so each station also had an adult helper.
• I had pre-written the first part of the code for students, and already laid out the labeled "broadcast" blocks that students needed, so all they had to do was to put the "redon/off, yellowon/off, greenon/off" and "wait" blocks in the correct order.

Challenges:

• I had expected students to struggle with reading the blocks, but luckily there were enough readers in this group of students that they had no trouble differentiating between the words red, yellow, and green on the Scratch blocks.
• The biggest struggle was with learning how to use the mouse; most of these 5 year olds were used to touch screens, but not 3-button mice.

The Results:

Every team was able to get their LEDs turned on! Some teams even had time for me to teach them about loops, and others started playing with the order of the lights to see if they could extend the coding lesson on their own. 

*For those that aren't familiar with what TK is, the abbreviation stands for Transitional Kindergarten. Not to be confused with either Pre-K or Preschool, TK is an option for children who do not meet the "5th birthday before September 1st" requirement for entering Kindergarten in California-- an introduction to Kindergarten for the "young 5-year-olds".