Hardware information for Raspberry Pi setups

Raspberry Pi 2

The Raspberry Pi 2 has fewer and lower spec components and so draws less power, but requires a WiFi adapter to be also purchased. The spec makes no difference to the OpenAPS app, so either model is suitable choice.

Raspberry Pi 2 Model B

Raspberry Pi 3 Model B

The Raspberry Pi 3 has higher specs and built-in WiFi and Bluetooth, so it draws more power. As a consequence, it has a shorter battery life than the Raspberry Pi 2. So when selecting portable battery packs bear this in mind.

Raspberry Pi 3 Model B

Micro SD Card

An 8 or 16 GB micro SDHC card is recommended. Get one that is class-4 or greater and is a recognized name brand, such as SanDisk, Kingston, or Sony. A list of verified working hardware (including SD cards) can be found here.

SanDisk Ultra 16GB Ultra Micro SDHC UHS-I/Class 10 Card with Adapter

Sony 16GB Class 10 UHS-1 Micro SDHC

Note: A known issue with the Raspberry Pi is that the SD card may get corrupted with frequent power cycles, such as when the system gets plugged and unplugged frequently from an external battery. Most core developers of openaps recommend purchasing extra SD cards and having them pre-imaged and ready to use with a backup copy of openaps installed, so you can swap it out on the go for continued use of the system.

WiFi Adapter (Raspberry Pi 2 only)

A minimalistic, unobtrusive WiFi USB adapter is recommended. The low-profile helps to avoid damage to both the RPi2 and the adapter as the RPi2 will be transported everywhere with the user.

Edimax EW-7811Un 150Mbps 11n Wi-Fi USB Adapter

Buffalo AirStation N150 Wireless USB Adapter

2.1 Amp USB Battery Power Supply

A large-capacity power supply that is greater than 8000 mAh (milliAmp-hours) is recommended for full day use. Make sure that the battery has at least one 2.1 Amp USB output. A battery with a form-factor that minimizes size is recommended, to allow the patient to be as ambulatory as possible. When you have a full OpenAPS implemented and working, you will want to have multiple batteries to rotate and recharge. A battery that can deliver power while it charges is ideal as you will be able to charge it on-the-fly without shutting down and restarting the Raspberry Pi.

TeckNet® POWER BANK 9000mAh USB External Battery Backup Pack

Zendure® 2nd Gen A3 Portable Charger 10000mAh - 2.1a Dual USB - in-line charging

USB Cables

USB cables with a micro connector on one end and a standard (Type A) connector on the other are used to connect the power supply and the Dexcom receiver to the Raspberry Pi. Most cables will work fine, but some prefer to select lengths and/or features (such as right-angled connectors) to improve portability.

Rerii Black Golden Plated 15 cm Length Micro-B Male Left Angle USB cable

Monoprice Premium USB to Micro USB Charge, Sync Cable - 3ft


The Raspberry Pi is extremely minimalistic and does not come in a protective case. This is fine for development work, but presents an issue for day-to-day use. There are hundreds of cases available, but here is an example of what others are using in their OpenAPS builds:

JBtek® Jet Black Case for Raspberry Pi B+ & Raspberry Pi 2 Model & Raspberry Pi 3 Model B

Additionally, for mobile use, it is helpful to have something besides a lunchbox to carry the entire rig around. The size and weight of the component set as well as the limited range of the CareLink USB stick constrains the options here, but there are still some workable solutions. Waist-worn running gear and camera cases seem to work well. Two options: FlipBelt and Lowepro Dashpoint 20.

HDMI Cable, USB Keyboard, USB Mouse

For the initial set up of the Raspberry Pi you may want to use a monitor and keyboard/mouse to set up the WiFi connection, but all other access can be done through a SSH Terminal (explained later). This means the monitor, mouse, and keyboard are only used for a few minutes and generally aren’t required again.