Raspberry Pi Shopping List
The Raspberry Pi is a $45 computer. Trouble is, it needs more stuff to make it go. This Raspberry Pi shopping list will help you be sure you have all the essentials and will suggest add-ons that will let your students do more experiments and build more things. Many of the prices below are from the spring of 2019. If you find problems with this list, please tell me by writing to Bob.Brown@Kennesaw.edu. I want to correct errors and make this a truly useful list.
I recommend one Raspberry Pi with parts kit for every two students; that allows students to work in pairs and learn from each other. I've made a list of precautions your students should read.
The Bare Minimum
Although there are ways to connect remotely to a Raspberry Pi, students will learn best if they can put their hands on the equipment. The items on this list will allow one pair of students to use a Raspberry Pi and perform simple build-it experiments, such as making one face of a traffic light.
A Raspberry Pi: The newest, latest, greatest, and coolest Raspberry Pi (as of spring, 2024) is Raspberry Pi 5. However, they have a minimum price of about $80... if you could buy one; they out of stock in most places. For K-12 schools, I recommend the Model 4 B. It has a faster processor and, for more money, more memory. For a single purchase, get a Pi 4. For classroom use, if you're just starting out, get the Pi 4. If you already have some Raspberry Pis and you're not going to do a wholesale replacement, you may want to stick with the Model 3 B+. The reason is that the power supplies, cables. and cases used with the Pi 3 won't work with the Pi 4. Both models are available from Adafruit, which also has the power supplies recommended below, with a limit of two per customer. In other than pandemic times, Arrow often has them in quantity with free shipping. Newark and Chicago Electronic Distributors usually have quantities available, as does Microcenter.
I've recommended the Model 3 B+ or Model 4 because they have on-board Ethernet, four USB ports, and there are lots of accessories for them. The Pi Zero and Pi Zero W are less expensive individually, but you'll end up paying more in the long run because of the add-ons you will need.
A power supply: The Model 3 B+ needs a 2.5 amp power supply with heavier-gauge wire than one finds in phone chargers. Adafruit has the right power supply for $7.50. There's a check-block in the link to buy a Raspberry Pi that will add one to your order automataically. The Pi 4 needs more power and a USB-C connector, so power supplies for the Model 3 B+ will not work with the Model 4. Because of a quirk in the way the Pi 4's power circuitry was designed, not all power supplies will work on Pi 4s made before about December, 2019 even if they have the right connector. For the Pi 4, get the official Raspberry Pi Foundation power supply. These should be available from the same place you get your Raspberry Pis.
Don't skimp on power; your Raspberry Pi might run erratically or not at all with an inadequate power supply. Note: Although the connectors are the same, most cell phone chargers will not provide sufficient current to run a Raspberry Pi.
An SD card, possibly with operating system: In place of a hard disk, the Raspberry Pi uses a micro SD card, such as might be used in a camera. The Raspberry Pi Foundation recommends the SanDisk brand. You can buy cards with an OS installer already loaded, but you can save money by buying a five-pack of blank SD cards for less than $36 and installing the operating system yourself. A larger card probably isn't necessary unless you are doing something unusual, such as duplicating multiple cards. You can get a blank 64GB card for $10 from Amazon; 32 GB cards cost only about $8.00 each in packs of two. If you need more than a few, we've been very happy with cards from Bulk Memory Cards.