Before you start, you’ll need the following:
- A Raspberry Pi Model B
- A 4 GB or greater SD card. Some cards may not work, see this page for a selection of tested cards.
- A power source for the Raspberry Pi. Our tutorial is based on the Powergen PGMPP8400, and we highly recommend it. Ensure that your battery has two USB ports and at least one can output 2A.
- A USB wireless adapter. We use the Airlink101 AWL5088.
- A Finch.
- A Powered USB Hub. We use the Plugable 4-Port hub.
- If using our mounting solution, 3D print or buy our Finch/Raspberry Pi mounting plate. The STL file is available for anyone to print.
- If using our mounting solution, a stretchy velcro strap.
- Velcro with sticky backing or double-sided foam tape is recommended.
- A one or three foot USB A to B cable might be easier to use than the Finch’s standard 15 foot USB cable.
Connecting the Raspberry Pi to the Finch is not as simple as it may seem. Due to the fact that the Raspberry Pi’s USB ports are unable to power the Finch through a power surge (such as those caused by the robot’s motors starting), we need to separate power for the Finch from USB communications with the Finch, hence the need for a USB hub. The following tutorial walks you through connecting the robot to the Pi through a powered hub.
Configure the Powergen battery by connecting the 0.6A output to the micro-USB connector (for powering the Raspberry Pi) and the 2A output to the yellow tipped barrel connector (EIAJ-02 standard).
Place the battery in the Finch/Raspberry Pi mounting shell such that the power switch and USB connector are accessible through the large rectangular hole on the right side of the mounting shell. We recommend affixing the battery to the flat underside of the shell with foam tape or sticky-backed velcro.
Thread the mounting strap through the two smaller rectangular slots on either side of the shell, then place the USB Hub on top of the battery, affixing it with tape or velcro. Connect the yellow-tipped barrel connector from the battery to the USB Hub’s power input. Connect the Mini-B USB cable that came with the USB Hub to the Mini-B USB port on the Hub. Connect the Finch’s USB Cable to one of the four ports on the USB Hub.
At this point, three cables are unconnected:
- The USB B cable goes to the Finch
- The USB A cable goes to one of the Raspberry Pi’s two USB ports.
- The USB Micro-B cable go to the power input for the Raspberry Pi.
Connect the USB B cable to the Finch and place the entire mounting shell on the Finch’s back. Ensure that the two Raspberry Pi cables are routed through the small rectangular slot in the back of the shell. Use the velcro strap to mount the shell securely to the Finch.
Now place the Raspberry Pi on top and affix it via the mounting holes, tape, or velcro. Connect the remaining two connectors to the Raspberry Pi and you now have a fully functional, Pi-powered robot!