Why do you need a Carberry for your car? Carberry forms a link between the car electronics and the tiny, inexpensive, versatile single board computer, the Raspberry Pi (RBPi). In sort, Carberry is a shield for the RBPi microcomputer and allows an enthusiast to develop end-user applications such as internet, carputing, burglar alarms, blackboxes, tracking, fleet management, data logging, vehicle diagnostics, media centers and much more.
Carberry can sit directly atop your RBPi, as it has the same form factor, and connects to the RBPi with the help of a 26-pin GPIO header, which is located on the Carberry PCB. You connect it to your car via a 22-pin Microfit connector, also on the PCB. Although the Carberry needs a 12VDC supply, it generates the 5V, 1A onboard for the RBPi and uses the ground connection from the vehicle. For managing the power flow to the RBPi, Carberry controls the 5V supply with a mosfet.
This also helps in performing a controlled shutdown, as it controls the power to the RBPi in the case of a logical shutdown. The entire combination follows automotive standards of low power consumption and normally consumes less than 3mA. Carberry communicates with the RBPi through the UART and utilizes pins 15 & 16 of the RBPi header.
Carberry provides ignition signal output at +12V, 2.5A controlling it through a mosfet. It reserves two CAN Bus lines and two GMLAN lines for parallel or series connection to the vehicular bus. On board, two channels are reserved for controlling a resistive steering wheel and this has the capability of being bypassed with a single key.
The general purpose UART operates at 5V or 3V3, as required by the user, while the two general purpose, open collector outputs can sink 500mA. There are two general purpose user-programmable LEDs and two general purpose inputs – the user can select the referencing to the ground or to 5V.
Carberry operates on a Microchip PIC32X microcontroller and provides a button and two-color LEDs for resetting and learning can bus profiles. If required, the user can send PWM signals to the RBPi for managing LIRC.
Cranberry can emulate infrared remote controls for media centers via the controls of the steering wheel, with the infrared sensor being suitable for 38 KHz. The board has an infrared LED onboard for the IR codes emission.
Other features of the Carberry are the user can develop applications under Linux that are ready for Apple MFI compatible. The on-board RTCC is capable of handling date and time along with battery wakeup and RBPi wakeup at programmed date/time.
An onboard external EEPROM comes with a unique identifier and users can utilize it for any license related to the card. Onboard accelerometer and magnetometer provide anti-theft features, blackboxing and positioning. The accelerometers and magnetometers can wake up the RBPi with their events, while the microusb device connector offers a stand-alone functionality for the shield in the future.
The user can upgrade the Carberry firmware via the RBPi and they can interface the Carberry to the RBPi via ASCII strings, similar to controlling modems with AT commands.
