Graeme and Phil set up “router 2” which provides a “hopping” internet link across a 1km stretch to let us cover the peatland on the plateau
Category Archives: News
Long distance 6LowPAN test completed!
Today we managed to carry out a long distance 6LowPAN network link: from the valley, 3km up to the mountain and then on to another node 1km further away (router2). This is confirmation that Graeme’s CC1120 Contiki driver works very well and we can start to deploy the sensor nodes around the mountain.
Testing the radio links in the Cairngorms
The antennas were tested in Glen Feshie – between thevestate buildings and the ridge 3.8km away and performed as well as we expected with the TI CC1120 transceivers. We now have a way to link the mountain’s sensors to the web!
This shows the distance covered by our first radio “hop” up to the mountains
Range testing 868MHz radio links
I just did a quick range test with the CC1120 transceivers (our favourite for range):
at 2.2km it is easy to link even with omni antennas (-99dB) but a yagi was excellent (-89dB).
At 3.3km (not in good line of sight and grazing wet ground) Yagi to omni was starting to loose packets (-106dB) and yagi to panel antenna was not much better but still communicating. This bodes well for a low power 868MHz network over the whole field site including our 3km link up from the valley.
This was at 50kbit/s using the CC1120DK TI test boards.
big round Omni was 4dBi gain
Yagi tested was 9 dBi gain
Panel was 7dBi gain