Arduino_AIS is a simple AIS receiver based on Silicon Labs Si446x EZRadioPro receiver, using an Arduino (3.3 volt nano used for testing)

AIS, short for "Automatic Identification System", is a tracking system for ships. More on Wikipedia. There are many websites dedicated to tracking ships based on this system, like for example MarineTraffic.

Arduino_AIS features:

• can be used with arduino Nano 3.3v and an off the shelf si446x module
• integrated radio, no need for external radio with discriminator tap
• hopping between channel A (161.975 MHz) and B (162.025 MHz)
• receives, decodes and validates packets according to ITU-R M.1371-4 (NRZI decoding, bit-destuffing, CRC validation)
• wraps valid packets into NMEA 0183 sentences (AIVDM)
• sends NMEA sentences to PC via serial (9600 8N1)

The output of Arduino_AIS can be processed and visualized by mapping and navigation programs like OpenCPN.

All content of this project is published under CC BY-NC-SA - Creative Commons Attribution-NonCommercial-ShareAlike.

• if using an arduino nano
• vcc on radio to 3.3v
• gnd on radio to gnd
• gpio2 on radio to pin d2
• irq on radio to pin d3
• nsel on radio to pin d4
• gpio1 on radio to pin d5
• gpio3 on radio to pin d6
• sdn on radio to pin d8
• mosi on radio to pin d11
• miso on radio to pin d12
• clock on radio to pin d13

When buying the si446x module make sure it has a 30mhz crystal rather than 26mhz and that it has connectors for all the GPIO Pins you will have better success with the ones that don't have an antenna switch. you can directly connect on a 3.3v Arduino or use 1k limiting resistors D4, D8, D11, D13 on a 5volt version to limit the current