dAISy HAT - AIS Receiver for the Raspberry Pi

The dAISy HAT is the perfect AIS receiver for your Raspberry Pi projects and embedded applications.

This two-channel marine AIS receiver works great with OpenCPN, Kplex and other software that accepts serial data input. It is also well suited for reporting local ship traffic to services like MarineTraffic.

We also offer a case for the AIS HAT, 162MHz pre-amplifiers as well as SMA to SO239 and SMA to BNC pigtail cables.

We also offer the Wegmatt dAISy 2+ Receiver!

Specification

Note: On the Raspberry Pi 3 and 4, UART0 is occupied by the built-in Bluetooth radio. Bluetooth may not be available when using the dAISy HAT!

• True two-channel receiver, continuously receiving on AIS channels A (161.975 MHz) and B (162.025 MHz)
• Superior sensitivity compared to other low-cost AIS receivers
• Low power, less than 200mW in receive mode (<40mA at 5V)
• 38400 baud serial output in industry-standard NMEA format (AIVDM)
• Communicates with Raspberry Pi via UART0 (serial0)
• Works with Raspberry Pi 1 (A+/B+ only), Pi 2, Pi 3 and 4 (see note below), and Pi Zero
• Shape and size compliant with Raspberry Pi HAT standard
• Breakout pads for 2 independent TTL serial outputs, 3.3 and 5-volt rails, and Raspberry Pi I2C port
• SMA antenna connector
• SMA-to-BNC adapter and hex standoffs included

dAISy works great with OpenCPN and OpenPlotter

OpenCPN, an open-source chart plotter and navigation software, can be used with receivers like dAISy to track ships on a map. Any software running on the Raspberry Pi that accepts AIS data from a serial input will work with dAISy.

Several of our customers built chart plotters based on Raspberry Pi, OpenCPN and dAISy. A detailed step-by-step recipe can be found here.

With Kplex the Raspberry Pi can be set up as an NMEA server that distributes AIS to other devices on your network, like for example via WiFi to a navigation app running on an iPad or Android tablet.

Disclaimer: WE DO NOT RECOMMEND relying solely on dAISy for navigation and collision avoidance!

Reporting to MarineTraffic

The dAISy HAT is well suited to report nearby ship traffic to AIS tracking websites and services like MarineTraffic, FleetMon, AISHub or Pocket Mariner.

The easiest approach is to use dAISy with Kplex. Kplex is a NMEA-0183 Multiplexer which allows you to feed the AIS data streams to multiple targets, including services like MarineTraffic and AISHub.

Advanced users can use a few lines of Python or even basic Linux commands to directly submit the serial output of dAISy to AIS tracking services.

Breakout Pads

The dAISy HAT includes convenient breakout pads to access the AIS data stream. With a bit of soldering, advanced users can combine dAISy with a Bluetooth module to receive AIS on wireless devices, connect a data logger like SparkFun OpenLog, or any other device that can process serial data.

• Serial 1 mirrors the serial data sent to the Raspberry Pi, running at 38400 baud. This output is always enabled.
• Serial 2 is disabled by default and can be configured to input or output at a different rate (4800, 9600 and 38400 baud).
• TX/RX voltage level is at 3.3V.
• 5V pads connect to the 5V rail of the Raspberry Pi, maximum load supported depends on the power supply
• 3V3 pads connect to dAISy's 3.3V rail, maximum load supported is about 150mA
• I2C breakout pads are directly connected to the Raspberry Pi, making it easy to add sensors to your project

Standalone Operation

The dAISy HAT also works without a Raspberry Pi when powered through the broken-out 5V or 3.3V pads. Use the serial breakout pads to connect it with a TTL serial-to-USB cable, Bluetooth module or other devices.

How dAISy compares

With our open source work, we pioneered a new category of AIS receivers designed around the SiLabs EZRadioPro single-chip radio IC. This architecture is instrumental for the very low price, small form factor and low power consumption. The trade-offs are longer acquisition time, lower sensitivity and less range than some traditional AIS receivers.

Field tests with conventional dual-channel AIS receivers showed, that under good conditions the dAISy HAT can be on par with some models (e.g. SmartRadio SR162) while still being outperformed by others (e.g. advanSEA RX-100). However, dAISy clearly outperforms all sub-$100 receivers that we have tested so far (Quark-elec, MarineGadget).

Our observation is, that with a good antenna dAISy is well-suited to monitor local ship traffic. If you need maximum performance and are willing to pay for it, go with a receiver from the established brands.