Solar powered telemetry system
Telemetry system based on nRF905 and nRF9E5 transceivers:
- bi-directional radio link, BFSK modulation, ISM 868MHz band, over 400 m range in open space or 2-3 floor levels in building,
- hardware with minimal energy demand,
- amorphous silicon double-stacked solar cells as primary power supply for remote nodes,
- DLC (Goldcap/Supercap/...) used as energy storage for remote nodes, 2 x 1F/5.5V used in prototype gives work time (RF communication with 15 minutes interval) over 28 h without solar power,
- central station equipped with USB interface (PIC18F2550), PC software uses cross-platform libusb library,
- native interface to MySQL,
- www based user interface,
- main station with ability to work independently,
- simple RTC (POSIX time),
- EEPROM data storage, mini file system with wear-leveling,
- central station is USB or externally powered; data is buffered and stored in non-volatile memory when there is no USB connection.
Some photos:
