The interface board addresses the problems of physically connecting the arduino or other micro-controller to a typical boat. It provides screw connectors for the boats cables, and interfacing and converison of NMEA signals to 5VTTL. Plus it has connectors for GPS, and various relays and sensors. It can be used on Arduino Mega or Due, and potentially on any other microcontroller by replacing the smaller board (arduino shield) with a suitable adaptor for your platform.

Boards are no longer available as of 9 Feb 2018 - sorry



The blue pcb with USB attached is the arduino. The ribbon cable connects the shield to the main board, which has all the real functionality. All the connectors use screw plugs, but as you can see the screw plug is the wrong sized part, replacements arrived today (25May) so its ready to ship!

The full spec is:

  • Power: 5V, supplied via usb, or cable. Use an automobile USB power supply.
  • Interfaces:
  • 1 x 5V TTL serial for GPS (EM406GPS just plugs on, but others can be used.)
  • 1 x Seatalk or NMEA (chose by setting jumpers)
  • 2 x NMEA
  • 1 x NMEA (talker only)
  • 1 x 5V TTL Serial (to drive autopilot controller)
  • 2 x 3A MOSFETs, 1 to drive autopilot engagement solenoid, and 1 to power external alarms
  • 1 x log, 5V, for paddlewheel sensor
  • 1 x wind - currently supports Peet Bros anemometer
  • 3 x upper/lower level alarmed analogue sensor inputs
  • 1 x CAN Bus (NMEA2000), or optionally 2 more simple on/off 5V sensors
  • 1 x ethernet - so you can connect to the RaspberryPi/Beaglebone/UDOO without opening your box.
  • Connection to arduino is by a shield and ribbon cable
  • External connections by 3.5mm pluggable screw connectors, except wind (RJ9), ethernet (RJ11), and power (USB)

The majority of these interfaces are defined by software on the arduino, so they can be repurposed with some code changes. Software to drive the 5V on/off sensors, the autopilot controller, the log, and solenoids is incomplete.

The CAN(NMEA2000) functionality will only work on the Due, which requires a lot of software porting - experimental for experts only.

The final cost in USD, exclusive freight and local taxes:

  • Completed inteface board, no soldering required: $100
  • Full kit all parts, soldering required (lots of through hole, a few smd parts): $70
  • Pcb board only, with parts list only: $30

(The GPS shown in some photos is not included)

The freight will be whatever method you prefer, but std is airmail from NZ, 3-10 days, for USD18.

There is no warranty but I will provide support on a best efforts basis if there are minor problems. If the board is unuseable I will replace it or refund your money. All risks in deciding to use the boards are yours, you agree by confirming your order that my maximum liability in any circumstances is refund of your payment.

Questions? email

Boards are no longer available as of 9 Feb 2018 - sorry