A Micronet / NMEA bridge for TTGO T-Beam V1.1 boards

Description

MicroNav is a ESP32/Arduino project aiming at converting data from Raymarine/Tacktick wireless network called Micronet to a standard NMEA0183 stream, easily useable by your laptop or tablet software.

MicroNav is the successor of MicronetToNMEA project. It aims at using a simpler, cheaper hardware platform with less soldering work.

WARNING : MicroNav is still in early phase of development. It is unstable and unfinished. You should not use it for navigation purpose, only for development. If you need a stable project to connect your Micronet network to your PC/Tablet/Phone, MicronetToNMEA is a better choice as it has now reached a good stability level and is reported to work fine by several users.

MicroNav can :

• Send T-Beam's GPS data to your Micronet network (Position, COG, SOG, DATE, TIME) and to the NMEA link (GGA, RMC, VTG)
• Send Navigation/guidance data from a navigation software (OpenCPN, AvNav, qtVlm) to Micronet network (BTW, DTW, XTE, WPNAME)
• Send Micronet's data to the NMEA link (MWV, DPT, MTW, VLW, VHW, HDG, XDR). NMEA link can be USB or Bluetooth. Wifi will come later.
• Send Magnetic heading from LSM303DLHC to Micronet network and NMEA link (Underwork)
• Be configured to match your boat configuration : you can select which set of data is received from which link (NMEA, Micronet, GPS or LSM303)

The project requires the following hardware :

• At least one display of the Raymarine/Tacktick Wireless system (T110, T111, T112, T113, T210 ot T215)

• A 868 or 915MHz TTGO T-Beam v1.1 with SX1276 RF IC and OLED display (like this one). You should check on which frequency is your Tacktick system communicating, 868MHz for EU system or 915MHz for non EU, and select the corresponding T-Beam version. Selecting the wrong one would reduce the operating distance of Micronav. Note that OLED display is mandatory since Micronav can't be configured without it.

Optionally, you can add :

• A LSM303DLHC, connected through I2C to add magnetic heading to your Micronet network

The type of construction described here is fun and interesting to play with, but anyone with a little bit of experience at sea knows that it will not last long in the wet, salty and brutal environment of a sailing boat. MicroNav will abandon you just when you really need it. No garantee can of course be given that this software will do what it has been designed for. This is a DIY project, not a professional product.

If you want a robust, reliable and extensively tested Micronet device, you should better go to your nearest Raymarine/Tacktick reseller.

Author & Contributors

• Ronan Demoment - Rodemfr - Main author
• Dietmar Warning - dwarning - LSM303 Compass, bugfixes & testing.
• j-lang - UBLOX Initialization code

License

MicroNav is licensed under GPLv3. See LICENSE.txt file for more details.

Compilation

MicroNav's source code has been developped with Visual Studio Code and PlatformIO plugin. It is strongly advised to use these tools to compile the code if you don't want to enter in the swampy grounds of embedded software compilation.

Acknowledgments

• Thanks to the guys of YBW.com forum who started the work of investigating Micronet's protocol. The technical discussions around the protocol are in this thread : https://forums.ybw.com/index.php?threads/raymarines-micronet.539500/
• Thanks to all the users of MicronetToNMEA & MicroNav who are giving feedback and reporting problems to help improving the system.

Development status

Fully operational:

• Micronet RX/TX with SX1276 at 868Mhz
• GPS Decoding
• NMEA through USB
• NMEA through Bluetooth
• Interactive configuration using OLED display & button

Not tested:

• Micronet RX/TX with SX1276 at 915Mhz
• LSM303DLHC Driver (Magnetic heading)

Not developped:

• NMEA through Wifi
• Power saving & battery handling