The program is written in our Eon language, with a runtime system designed for solar charging.
Sources for the Eon compiler, adaptive runtime system and turtle program as well as our hardware designs are available here.
We initially used the following hardware in the Turtle nodes:
- SiRF Star III-based GPS Receiver pulled out of a Deluo receiver
- Ultralife UBC581730 250 mAh Battery
- XBow Mica2Dot Mote
- Custom designed charging board. Schematics available. If you want board layouts, etc, please contact us.
- 4.2V powerfilm flexible solar cells
- The node is packaged in shrinkwrap tubing and the ends are sealed with 30 minute, waterproof epoxy
In later deployments we have made the following improvements:
- Replaced Mica2Dot with a TinyNode (Shockfish) to increase radio performance.
- Charge board upgraded to accomodate the TinyNode.
- Use higher-efficiency 6V solar panels from Solarbotics (SCC3733).
- Custom plastic enclosure, sealed with epoxy.
- Many elements of the hardware design were borrowed from the HelioMote project.
- The mote turns on when the battery reaches 3.6V, and turns off when the battery reaches 3.1V (hysteresis)