Electronics


Designing the control board for the rrMM may be the most challenging task when building the boat. As the boat is typically too small to carry, e.g., a netbook, a small custom board was designed using EAGLE. We will subsequently give you all necessary information to build a board, though getting the components and soldering some of the parts can be challenging.


Boards


Below you will find some information regarding boards we have build that actually work. However, we don't give any guarantee with respect to these boards, and you should carefully check the design before having a board built.

Main Control Board


This is the main board holding an ATMega processor and the serial bluetooth module, as well as all connections to read sensor data and control the servos. List of parts
Circuit layout Main-PCB circuit layout Main PCB Back Main PCB Front PCB in Cover

USB Bluetooth Board


This is a small board to build a long range bluetooth antenna base on the F2M modules. List of parts
Circuit layout GPS-PCB circuit layout

GPS Board


This board is designed for the ublox LEA-4T chip. While there may be advantages in placing the GPS chip on the main board, we mostly wanted to be able to quickly exchange a failing parts, as the GPS chip is rather expensive. The LEA-4T was chosen to allow for DGPS, however, cheaper chips may be sufficient to get started. List of parts
Circuit layout GPS-PCB circuit layout GPS Back GPS Front


Sensors


Some sensors like the accelerometer or the compass are integrated with the main board. However, one essential information for sailing is the wind direction, for which we built a very small sensor based on a magnetic encoder. So far, these sensors have proven surprisingly robust, though getting the ball bearings fixiated can be tricky.

Wind Speed and Wind Direction


Wind Speed
Wind speed and wind direction sensors are based on the Austria Microsystems AS5040 rotary magnetic encoder. The housing was made from ABS using a 3D printer, and a small magnet is glued to a 1 mm carbon fiber rod. The rod is held by ball bearings to reduce friction. ToDo: sensor board.
Wind Sensors

Partners Universitaet zu Luebeck Beltec GmbH