Wireless sensor network - Smilenet
Wireless sensor network
Method:
Summary:
Radio frequency used:
Radio protocol used:
Range/Power (line of sight/dBm):
20 km line of sight
300 m wet forest
868 MHz
300 mW TX power
l/4 antenna
Hop modes:
Point-to-multipoint
Zigbee (not reliable)
GPRS:
Mesh limitations:
number of sensors:
number of nodes per router:
Additional information:
Sensor compatibility:
1 Wire
Digital IO
8 channel 10 bit AD converter, 0 to 2.5V
Frequency counter
Future: I2C, SDI12 ?
Data reading frequency:
Adjustable, e.g. 30 s, 1 min, 15 min
Storage of data/backup:
SD card on node (e.g. 2 GByte)
CF card on Gateway (4 GByte)
Server with database on Internet
Data format: plain ASCII text file
Power consumption:
Sleep mode: about 40 uA
Active mode without radio/sensor: 8 mA
Active mode with soil moisture sensor: 50 mA for 400 ms
Active mode with radio RX: 50 mA
Active mode with radio TX: 150 mA
Reliability:
Years in service:
Failure rate instrument (years):
Packet failure (%):
Installation procedure:
Installation underground possible:
yes
Battery life:
1 min interval: 2 weeks
90 min interval: approx. 2 years
Battery type
4x AA, 6V (5.2 V)
Sanyo Eneloop NiMh rechargeable, 2000 mAh, self discharge about 15% in 1 year
Alkalines as well (solar power optional in future)
Maintenance required /Ease of maintenance:
Support:
Software:
Web friendly interface:
Data base:
Scripting language:
Ease of update:
Open source:
Cost (non profit):
30 Euro microcontroller board
15 to 50 Euros radio (depending on frequency and power)
Gateway: 135 Euro embedded pc +30 to 65 Euro for radio modem
GPRS: 150 Euro
Communication costs: 0.2 Euro for 1 MByte
What to watch out for:
Problems/Questions:
Links
Projects that used the above equipment:
Other related web sites:
Technical information
Distributors