LoRa transmission from low orbit satellite during The Things Conference

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Would be around 23:00CET.

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I was doing some checks and I reckon the loss for a receiver listening on 162Mhz with a 434Mhz module is not very great, a few dB maybe. I can explain how I came to that conclusion tomorrow if you like.

Anyway one of my simple Arduino Pro Mini based receivers was propped up against the window of my Hotel room and picked up 5 packets on this evenings 10:12 ish pass, the SNR and RSSI are printed below, but I am only showing the first two characters of the messages, don’t want to reveal the secret;

SNR,-18dB RSSI,-107dB le
SNR,-19dB RSSI,-109dB TT
SNR,-18dB RSSI,-109dB TT
SNR,-17dB RSSI,-108dB le
SNR,-18dB RSSI,-108dB he

SNR is on the limit for SF11.

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Not in need of eternal fame and glory? :wink:

(Hiding the other messages until the keynote might be nice indeed.)

No need to spoil the fun for others who may want to try.

One tip I would suggest is that you also display the results for packets that fail packet CRC check. The SX1278 will allow you to print the buffer for a corrupt packet so you can get more clues.

Congratulations! Well done, and thanks for trying the 433 module.

Thomas

Although I received 6 packets in total, I did not pick up the secret one.

The module I used was a 434Mhz Hope module, antenna was a dual 2M\70cm portable antenna.

So I guess the ‘prize’ is still to be won.

Very nice to see the telex printing the messages twice a day. And quite a nice idea Thomas’ company http://www.lacuna.space has!

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indeed very impressive, imagine one ‘super’ satellite gateway…

OK, Thomas…, the telex printing and bells ringing made for a very inspiring presentation. Well done!

Now rigging a LoRa receiver for 162MHz with some parts I have on the desk. A hopeRF module, Raspberry PI and an antenne for receiving aircraft transmissions. Obviously the antenna goes on the roof.

IMG_5031

Waiting for the satellite to pass overhead…

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So my setup did not catch anything. I had to step out of the office during the pass of the satellite, you know work…

So I set the LoRa receiver to continuously receive SF12 messages @162MHz. Not taking into account doppler shift or anything. So I might be listening at the wrong frequency… Nothing received during this pass. But that makes sense because I just saw Thomas’ post saying it is transmitting on SF11.

Oh well, will try with a more elaborate setup and the correct SF during the next pass of the satellite… :slight_smile:

Just to make sure:

Center frequency: 161.862500Mhz
Bandwidth: 125kHz
Sync word: 0x12
Spreading: SF11
Low Data Rate Optimize: on
Header: on
Coding Rate: 4/8 (this is in the header, no need to configure)
IQ inverted (this is default for rx, don’t change anything)

Good luck tonight!!

Thomas

Thanks Thomas,

Yes I set the center frequency to 161.862500MHz too now.

Maybe I have time to quickly put together a cross yagi antenna @ 162MHz for tonight. Don’t know, lets see what bits and pieces I have in the shed for that.

Ivo, any luck?

Hi Thomas,

Nope. We just had another pass of Norsat 2. I installed ‘gpredict’ and configured ‘Norsat 2’ to actually see when the satellite is passing overhead. But so far my receiver is not picking up the LoRa signal from space.

When will the transmissions stop? As soon as the TTN conference is over? I like the challenge, but my setup needs some more tweaking I am afraid.

Cheers, Ivo

It stops tonight 0.00 UTC, so 1.00 Amsterdam time. Even though Stuart has won the prize, still nice to try! (Next pass around 13.35 Amsterdam time.)

@LoRaTracker, congrats on the prize!

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N2YO is showing passes at 22:41, which will be low in the sky for London/Amsterdam, and 00:17 over Ireland, which is technically tomorrow. Where are you getting 13:35 from?

DSC_0182

1 minute!

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What did he win? The telex printer used during the conference? :sunglasses:

DSC_0183

The previous one was very short…

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Telex has captured a few packets just now.