Phase02¶

Phase01 is completed and the Gumstix and the source code will be used for the Phase02, with the needed modifications.

The Goal¶

A remotely operated boat with a possibility to lower a camera to several meters deep under water.

A wireless ROV was the first goal but it seems that getting >100kbps wireless underwater communication with 100 meter range is a bit tricky task.

The Features¶

Suggested features:¶

Underwater Gumstix¶

Gumstix would be lowered underwater. It controls two servos turning the camera and encodes the video stream.

Issues: Hard to communicate with on-shore controller. Need to control the boat. Need to encode the video, so must be close to camera.

Boat microcontroller¶

A microcontroller would be on the boat controlling the boat motors and relaying the communication between the on-shore controller and the Gumstix.

Issues: How communicate with Gumstix? Need to be connected to GPS. Need to control the board motors.

Wired communication between Gumstix and microcontroller¶

A data transfer must exist between the processors.

Issues: must be fast and reliable enough for video streams.

Wireless communication between the boat and the on-shore controller¶

A data transfer must exist between the boat and the on-shore controller

Issues: 3G slow and not available everywhere. E.g. zigbee could allow just enough speed and range but would be disconnected from the internet.

GPS¶

Boat would have GPS connected to the microcontroller with uart.

Issues: Needs UART.

Pressure sensor¶

The underwater part would have a pressure sensor connected to the Gumstix for measuring the depth.

Issues: ?

Sonar¶

The underwater part would have a sonar to measure the distance to the bottom.

Issues: ?

Solar panel¶

http://www.sparkfun.com/products/9759

Issues: How to use solar panels?

Proper power supply¶

All parts (servos, motors, microcontrollers, and the gumstix) need proper steady power.

Issues: need to support multiple voltage levels.

Winch¶

Need to have a winch to lower and raise the underwater camera system.

Issues: How to save energy when the winch is stopped to any position?

Run-time power consumption measurement¶

The controller must know the current current power measurement (and maybe make some estimates about the remaining battery life)

Issues: How to measure total current and voltage?

Approved features:¶

None.

The plan¶

TBD.