The goal of this master class is to create expansion packs for the Lego Mindstorms NXT product. The student follow a series of lectures on the underlying technologies and in the end design and build their extension pack.
Tom van Bergen
Tom created a Lego water pump that is based on the Kavan 0190 pump (12V). He build a casing using a 3D rapid prototyping (SLS) machine. The pump’s two electronic connection points (positive and negative DC poles) were soldered directly to an NXT plug from Mindsensors, allowing the pump to be run forwards and backwards using PWM signals. The pump can be controlled in the same way as an old fashion DC LEGO motor. A benchmark test with the NXT showed the pump can push ~0.9 liter per minute at full power.
Martijn ten Bhömer
Martijn developed a GPS sensor that connects to the NXT with a cable using an intermediary micro controller. He used the NMEA-0183 standard to communicate between the USGlobalSat EM-406A GPS sensor and the micro controller. The micro controller then communicates with the NXT using the I2C protocol. In essence, the NXT is connected to the GPS sensor with a bi-directional communication.
Wireless Sensor Bridge
Tom build a wireless bridge between sensors and the NXT. The NXT is already able to communicate using Bluetooth, but naturally, the Bluetooth communication is limited to several meters. Tom used the XBee modules to enable communication between sensors and the NXT over more than 1km.
Optical Mouse Sensor
Martijn connect and optical mouse to the NXT using an intermediary micro controller. The system allows the NXT to read the coordinates of the optical mouse sensor. This is particularly useful for determining the position of mobile robots.
Elco used a magnetic latching solenoid to build a magnetic grabber. The solenoid used is designed for low duty cycle applications where the solenoid’s energized position is needed for an extended period of time. The plunger latches magnetically in his basic position, until a negative electrical pulse is applied to allow the plunger to unlatch. Elco also build a mechanical guiding system to allow the plunger to reliable enter the hole of the solenoid.