Note: This Instructable is designed to be a lesson guide for teachers to teach about the problem solving process.
Background: Raspberry Pi's are miniature computers, capable of running RaspbianOS (Linux) or one of many other Operating Systems. Unfortunately, the official case for the Raspberry Pi Zero does not allow enough room for both the camera module and a heat sink. This results in having to choose between: a) not using the camera module, b) forgoing a heat sink (which can lead to overheating and performance degradation, or c) utilizing a new case.
This lesson is designed to guide students (grades 9-12) through the problem identification, solving, and refinement processes.
Associated Standards for Technological Literacy:
11: Apply Design Processes
M. Identify the design problem to solve and decide whether or not to address it.
N. Identify criteria and constraints and determine how these will affect the design process.
O. Refine a design by using prototypes and modeling to ensure quality, efficiency, and productivity of the final product.
Required Materials (one set per group)
*Note: Many of these items can be found in sets on sites such as Amazon.com or Adafruit.com
- Raspberry Pi Zero
- Raspberry Pi Camera Module
- Raspberry Pi Zero Case (clear preferred so status lights can be seen within).
- Raspberry Pi Power Supply
- Micro SD Card (minimum 8 gigabytes)
- It is possible to buy an SD card with NOOBS (New Out Of the Box Software) pre-installed for an additional cost. If you choose to do so, skip Preparation Step 1.
- Monitor with HDMI in
- HDMI Cable
- HDMI to Mini HDMI adapter
- USB Keyboard
- USB Mouse
- USB Hub
- Micro USB to USB adapter
- Access to a 3D Printer.
Approximate cost: $45 per set (not including monitor, mouse, and keyboard):
- Raspberry Pi Starter Kit: $35
- Contains Raspberry Pi Zero, case, HDMI to Mini HDMI cable, ribbon cable (for attaching the camera module), Micro SD Card (16GB), Power Supply, Heat Sink, and USB Hub.
- Raspberry Pi Camera: $10
While this may seem expensive for a single lesson, the Raspberry Pi is a great, flexible tool for educators to teach skills such as coding, Internet of Things projects, or other STEM projects. Many lessons utilizing the Raspberry Pi can be found online.
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Step 1: Preparation
Step 1: 3D Print one of each of the attached STL files for each group. These will be used in the lesson to show a demonstration of a case with improved clearances and airflow.
Step 2: Install Raspbian OS onto each SD card. Directions can be found here: https://www.raspberrypi.org/documentation/installa...
Step 3: Familiarize yourself with the setup process for a Raspberry Pi Zero:
- Plug in the power supply into the port on the right (labelled "PWR IN" on the circuit board).
- Plug the HDMI cable into the monitor, then plug the HDMI cable with the Mini HDMI adapter into the port on the left (labelled "HDMI" on the circuit board).
- Plug the keyboard and mouse into the USB Hub. Plug the USB Hub into the Micro USB adapter, and plug the adapter into the port in the middle (labelled "USB" on the circuit board).
Step 4: Familiarize yourself with the Raspbian Operating System. While it is fairly straightforward, it may help to check out online tutorials if you have never used an operating system besides Windows or Mac.
Step 2: Lesson
Step 1: Give each group a Raspberry Pi Zero, camera module, case, power supply, keyboard, monitor, mouse, and USB Hub (with Micro USB adapter). Instruct your students to assemble the board within the case (without the heat sink).
While we will not be using the camera module during this experiment, its presence is important because many Raspberry Pi projects can utilize the camera, so a case that fits the camera and a heat sink may be necessary for those use cases.
Step 2: Allow the groups time to experiment with the Raspbian Operating System (installed on each board). Allow them to use the wireless capabilities of the card to connect to the internet (with the permission of your school's administration), or play the included Minecraft game.
Step 3: After about 10-15 minutes of use, ask your students if any of their systems are displaying a small thermometer on the desktop. Have your students open the Terminal and type the following command:
This will display the temperature of the CPU core in Celcius.
Ask your students if they know why it is important that computer chips stay cool (answer: to avoid damage to the silicon dyes, solder, or other components). Inform your students that computer processors are designed to "thermal throttle," or intentionally slow down the processing speed as a safety mechanism.
Step 4: Give each group a heat sink, and instruct them to attach it to the CPU of the Raspberry Pi board. Then, have your students reassemble the case. They should not be able to, due to the lack of clearance between the heat sink and camera module.
Step 5: Discuss with your students any design flaws they find. If needed, guide them towards the following:
- The camera module is an important tool, due the flexible nature of the Raspberry Pi.
- It is important that computer chips are able to dissipate heat to avoid overheating.
- Heat sinks include dissipation.
- The heat sink does not fit within the case with the camera module.
Step 6: Discuss with your students possible revisions to the case that allow for:
- A heat sink
- A camera module
- Adequate airflow through the case to allow warm air out of, and cool air into, the case.
Step 7: Have your students shut down the Raspberry Pi.
Step 8: Present each group with the 3D printed case attached to this Instructable. Guide them through the assembly of this new case:
- The Raspberry Pi board attaches to the base (the flat piece with no hole in the middle).
- The shell (the tall hollow piece) fits over the board, making sure to line up the holes for the power, HDMI and micro USB ports.
- The camera module attaches to the lid (the flat piece with a hole in the center), lining up the pegs with the holes in the camera module.
- The lid snaps onto the shell.
Step 9: Give your students another 10-15 minutes to continue using the Raspberry Pi board. After this time, have each group view the core temperature using the code above. It should be much cooler.
Step 10: Discuss with your students how changing the case allowed for improved temperature. Discuss any shortcomings of the 3D printed case, and how they would refine the 3D printed case further.