Raspberry Pi HAT offers NMEA 2000 link for marine applications
Jan 21, 2021 — by Eric Brown 5,341 viewsCopperhill’s $99 “PiCAN-M” HAT for the Raspberry Pi provides CAN-based NMEA 2000 and RS-422 driven NMEA 0183 ports for marine applications. The HAT includes a 3A SMPS supply and a Qwiic link.
In 2019, Copperhill Technologies launched a PiCAN3 CAN-Bus HAT for the Raspberry Pi 4. The new PiCAN-M (for Marine), built for Copperhill by SK Pang, offers a marine-specific, NMEA 2000 compatible version of CAN. The $98.50 HAT also supplies an RS-422-based NMEA 0183 interface plus a Qwiic interface for adding SparkFun’s Qwiic add-ons.


PiCAN-M with (left) and without the Raspberry Pi
(click images to enlarge)
Copperhill also launched an Arduino compatible Teensy 4.0 NMEA 2000 board for $99.95 with a 240 x 240-pixel IPS screen and a version with a 480 x 320-pixel 3.5-inch touchscreen for $114.95. Both Teensy boards are limited to NMEA 2000 and Qwiic connections.
NMEA standards for marine technology are established by the National Marine Electronics Association (NMEA). The earlier NMEA 0183 has drifted beyond the high seas and landed on terrestrial GPS devices for linking serial data to positioning. For example, we have seen NMEA 0183 support built into GPS devices used on handheld computers such as Epiq’s Matchstiq Z1 SDR device.
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The newer, CAN-based NMEA 2000 standard “defines a low-cost, modest capacity, bi-directional, multi-transmitter, multi-receiver instrument network,” according to Copperhill’s PiCAN-M announcement on Digital Journal. Typical data on an NMEA 2000 network used on a boat or ship include position latitude and longitude, GPS status, steering commands to autopilots, waypoint lists, wind sensor data, engine sensor data, depth sounder sensor data, and battery status data.


Copperhill conceptual diagram of a NMEA 2000 network (left) and a NMEA 0183 driven OpenCPN chart plotting screen
(click images to enlarge)
The PiCAN-M supports marine applications such as OpenCPN (Open Chart Plotter Navigator) and Signal K, an open data format for marine use based on JSON, WebSockets, and HTTP. Signal K enables easier data sharing via WiFi with mobile devices and via the Internet. There is also support for CANBoat, a suite of command-line driven programs that work with a NMEA 2000 network.


PiCAN-M detail view (left) and connected to a NMEA 2000 network and an unnamed QWIIC sensor module
(click images to enlarge)
The NMEA 2000 port is said to be implemented via a USB Type-C port, although we see nothing recognizable as such. The port is available with a SocketCAN driver and is said to be “120 Ω terminator ready.”
The NMEA 0183 interface uses a 5-pin terminal block. The PiCAN-M also integrates a 3A SMPS (Switch Mode Power Supply) to power the Raspberry Pi plus HAT from an onboard 12VDC source.
The Qwiic interface is based on I2C. There is also an LED and 40-pin GPIO extension. This is an open spec board with schematics and other resources.
Further information
The PiCAN-M HAT is available for $98.50, with free shipping within the U.S. More information may be found in the announcement and product page.
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