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srnet Senior Member Joined: 08/08/2014 Location: United KingdomPosts: 164
Posted: 10:29pm 19 Mar 2015
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This is my prototype MicroMite II LoRa Receiver.
Its primary purpose is to act as the base for a LoRa wireless transceiver in combination with my Arduino style RFM98 shield. Together they will receive tracking information and sensor data from high altitude balloons that use a LoRa transmitter.
The concept was to make a portable transceiver with low power consumption that would be able to track, and collect and log data from, a high altitude balloon at long distances independent of an Internet connection.
The screen shot is of the receiver displaying the received telemetry from a tracker.
Next, I need to add a small LCD display for portable use, where a PC terminal may not be available.
Edited by srnet 2015-03-21$50SAT is Silent but probably still working. For information on LoRa visit http://www.loratracker.uk/
srnet Senior Member Joined: 08/08/2014 Location: United KingdomPosts: 164
Posted: 10:39pm 19 Mar 2015
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The prototype LoRa receiver base provides;
Connection for a FTDI USB serial adapter.
Connection for 3.5mm Stereo jack serial console (AXE027)
PCF8563 RTC and backup battery.
32Kbyte EEPROM
4 ‘traffic’ light LEDs.
Switch.
Reset Switch.
Buzzer.
DS18B20 temperature sensor, header for additional external sensor.
OpenLog Logger, for logging data and with optional jumper to allow for logging of console output for debug purposes.
12v or 5V supply input options, allows for single lithium battery operation.
$50SAT is Silent but probably still working. For information on LoRa visit http://www.loratracker.uk/
WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2948
Posted: 10:45pm 19 Mar 2015
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Hi Stuart,
Can you give an indication as to how much the parts cost to make a transmitter/receiver pair!
Also, what range would you expect: 1: In air (i.e. HAB), 2: on ground in residential building environment.
Can you also indicate Tx and Rx current consumptions.
Sorry about all the questions; its just that I may have a use for such a setup but it depends on the answers to the above questions.
Thanks,
WW
plasma Guru Joined: 08/04/2012 Location: GermanyPosts: 437
Posted: 10:46pm 19 Mar 2015
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Hi ,
How long is long range and where can i buy a set
Transmitter/receiver?
Interessting project
srnet Senior Member Joined: 08/08/2014 Location: United KingdomPosts: 164
At full power (50mW) and 1000bps, expect about 500km to a HAB, more than 1000km at 100bps, but the Earth is too bendy for you to test that, unless the tracker is on a satellite.
Across a city, I got around 1km @ 1000bps, 2dBm (3mW), so maybe 2.5km @ 10mW.
Expect a lot of variation though, depending on terrain and antennas.
As a general guide expect between 10 and 30 times the range of conventional FSK modules. Edited by srnet 2015-03-21$50SAT is Silent but probably still working. For information on LoRa visit http://www.loratracker.uk/
srnet Senior Member Joined: 08/08/2014 Location: United KingdomPosts: 164
Posted: 11:18pm 19 Mar 2015
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RFM98s can be got in a few places, UK HABSuplies has them.
Around £5 each.$50SAT is Silent but probably still working. For information on LoRa visit http://www.loratracker.uk/
srnet Senior Member Joined: 08/08/2014 Location: United KingdomPosts: 164
Posted: 11:20pm 19 Mar 2015
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The summary link should be;
http://www.southgatearc.org/news/2015/january/lora_low_cost_long_distance_telemetry.htm#.VQvl_Y6xfLUEdited by srnet 2015-03-21$50SAT is Silent but probably still working. For information on LoRa visit http://www.loratracker.uk/
WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2948
Posted: 11:21pm 19 Mar 2015
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@srnet
Your setup looks much more than the RFM98 unit. Please can you indicate a rough cost for 'everything'.
Also, which document (in the links you posted) talks about range?
Thanks . . .
srnet Senior Member Joined: 08/08/2014 Location: United KingdomPosts: 164
Posted: 01:19am 20 Mar 2015
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Your looking for a document called "KISS approach to Long Range Data Telemetry"
I dont have a rough cost for the bits, never added them up.
$50SAT is Silent but probably still working. For information on LoRa visit http://www.loratracker.uk/
srnet Senior Member Joined: 08/08/2014 Location: United KingdomPosts: 164
Posted: 09:38am 20 Mar 2015
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Can you give me an indication as to the application ?
A MicroMite II LoRa receiver can be a great deal simpler, and lower cost, but it depends on what it is you want to use it for.
$50SAT is Silent but probably still working. For information on LoRa visit http://www.loratracker.uk/
WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2948
Posted: 10:09pm 20 Mar 2015
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@srnet
I can't go into details other than to say I need a 'long range' wireless link (3km in commercial environment). I have plenty of options I have used in the past but am looking for a MicroMite controlled/programable link. Hence the interest in what you have . . . .
WW
srnet Senior Member Joined: 08/08/2014 Location: United KingdomPosts: 164
Posted: 11:54pm 20 Mar 2015
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Its difficult to say without knowing the environment, position and type of antennas etc.
In terms of ISM devices, previously the longest range would probably have been from 868Mhz devices where 500mW\27dBm is permitted.
A LoRa tranceiver has around 20dB gain over previous conventional FSK devices, so by the time you take free space loss into account, a 434Mhz\10dBm LoRa device will have around 8dB better performance than a 868Mhz\27dBm device.
$50SAT is Silent but probably still working. For information on LoRa visit http://www.loratracker.uk/
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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