SHIPPING NOTE: This shield ships with a 5v/3A power supply. As a result, international shipping is rather expensive, due to the added weight (I charge less than actual shipping costs to help offset this). I have added an option to ship the board without the power supply at a reduced cost to make it cheaper to ship internationally.

NOTE: This shield has been updated to improve communications speed and protection. It now uses the NTSX2102GU8H dual-channel level shifter IC capable of 50Mbps. The new design allows for the increased speed with both I2C and SPI communications. Additionally, the SPI CLK line can now be used with the level-shifters in-line, which provides increased protection to both the rPI and Arduino. All orders will receive the new version of the shield.

This highly-configurable Arduino-compatible shield allows you to mount (and power) a Raspberry Pi Zero or Zero-W and communicate with an Arduino-compatible micro-controller via Serial(UART), SPI, I2C, or Logic-level pin signaling.

Provides bi-directional level-shifting for each connection and in-line current limiting resistors to protect the Raspberry Pi inputs.

Fully configurable with jumpers to connect/disconnect each Raspberry Pi and Arduino pin from the level-shifters to allow for full use of all pins and ports.

Works with 3.3v or 5V micro-controllers

Supports Arduino-compatible micro-controllers that use the standard UNO R3 header configuration such as the MEGA, DUE, UNO, Duemilanove, etc, or clones. NOTE: NOT ALL MICRO-CONTROLLER SUPPORT OPERATING IN SPI/I2C SLAVE MODE. CHECK THE SPECS ON YOUR BOARD.

Serial configuration jumpers allow for connecting the Raspberry Pi UART to the Arduino hardware serial port or Arduino pins 7 and 8 for use as a softwareserial port (this is Serial Port 3 on my Arduino-Teensy board). If the jumpers are removed, you can use the included jumper wires to connect the Pi UART to any pins on the Arduino board - this is required for boards such as the Arduino DUE as the DUE does not support softwareserial and holds the hardware serial port high, preventing the Raspberry Pi from communicating on it. Using the included jumper wires allows you to connect to one of the DUE's additional serial ports for full serial compatibility.

I2C connections have built-in pull-up resistors and bi-direction level-shifters that allow for full I2C compatibility. The recommended I2C speed is 50kbps for long communications strings or rapidly repeating transactions for maximum reliability. Shorter or less-frequent I2C conversations can occur at higher speeds. This is a limitation of the implementation of the I2C protocol on the Raspberry Pi and not due to the design of the shield.

The SPI connection is configured to use Raspberry Pi CE1 and allows you to use the Pi as Master to control the Arduino as a Slave (Raspberry Pi does not currently have driver-support for Slave mode). Each digital pin bridge has a built-in bi-directional level-shifter and current-limiting resistor for protection. SPI speeds were tested reliably up to 1Mhz (limited by Raspberry Pi's implementation of SPI clock).

NOTE: Not all micro-controllers support SPI SLAVE mode. If you intend to use SPI with this shield, verify that your micro-controller supports SPI SLAVE mode.

5 Raspberry Pi pins (includes the 4 SPI pins) can be used for bi-direction logic-level communications with the Arduino, allowing you to set a pin HIGH or LOW on the Raspberry Pi or Arduino and read its state on the other device - all with full voltage and current protection in-line.

The Shield can be powered via a 2.1mm barrel jack or micro-USB port (power only) and will also power the Arduino (or compatible) micro-controller and additional shields as well. This power is transferred to the micro-controller via the 5v pin and includes bypass and filter caps.

POWER SPECFICATIONS:

• The 2.1mm barrel jack, 6.5 - 12V supply (6-5 - 9V recommended), can supply the on-board 5V LDO with 2A total output current.
• The micro-USB jack can provide up to 2.5A total output current, with the included power adapter.
• Both inputs are filtered and have current-limiting poly-fuses for protection.
• DO NOT POWER THE SHIELD FROM THE ARDUINO MICRO-CONTROLLER AS IT DOES NOT SUPPLY SUFFICIENT CURRENT

Other Features:

• Reset switch for the micro-controller
• Shield power LED
• LED connected to Arduino pin 13
• LED connected to Raspberry Pi GPIO pin 13
• Female headers allowing for full-access to all Arduino pins. NOTE: You CAN stack shields on top of this shield by installing a non-stacking female header on the Raspberry Pi (included in Pi Kit) and using a header extensions kit (available for a small charge)
• ICSP header access for AVR Micro-controllers
• 3mm mounting holes for securely mounting Raspberry Pi Zero (W) to shield (mounting hardware included)
• Solder-jumpers to disconnect Micro-controller SDA/SCL pins from pull-up resistors
• Solder-jumper to disconnect Raspberry Pi GPIO13 from LED
• Example sketches for Serial/SPI/I2C/Logic-level communications for Arduino found in my Github account
• Example Python scripts for Serial/SPI/I2C/Logic-level communications for Raspberry Pi found in my Github account
• Instructions for configuring the Raspberry Pi to support Serial/SPI/I2C/Logic-level communication found in my Github account

NOTE: Example sketches were devolped on an Arduino UNO and may require adjustment to work on other micro-controllers.

Package Includes:

• Fully assembled Raspberry Pi Shield
• 5v 2.5A AC/DC power supply (US Plug)
• 3 Brass Standoffs with screws for mounting Raspberry Pi
• 3 4-inch male-to-female jumper wires

Optional Add-ons:

• Raspberry Pi Zero W KIT. Includes Pi Zero W, 16GB MicroSD Card, Mini HDMI Adapter, 6-inch OTG cable, regular (short) and extended 40-pin header - Note: I am unable to offer Raspberry Pi Zero Kits at this time due to availability
• Raspberry Pi 5MP camera/webcam (v1.3) with standard cable and Raspberry Pi Zero cable
• 5-Piece Arduino header extension kit. Allows stacking shields on top of the Raspberry Pi shield (requires use of 'short' 20-pin header on Raspberry Pi Zero.)