We have a receiver on the roof of the Rockstart building and a display (with a surprise) in the conference area that will show you the live position of the satellite and the received messages.
However, you can receive them yourself as well!
One of the messages will contain a secret code: the first person to post that code here on the forum will win a small price, but also gets the eternal fame and glory!
You will need an 169Mhz SX1276 module, and an antenna with at least reasonable performance around 162Mhz. (caveat: this proofs to be a very noisy band)
Please let us know if there is interest in this challenge, then I can post more details later. We also might have some modules you can use at the conference itself.
It’s an interesting challenge to try to receive the signals, but I don’t think my 868Mhz LoRa modules will function down at 162MHz. Perhaps I also need an SDR
So, say I have got a SX1278, set it to 169Mhz, manage to get hold of a correct antenna, would it then be a matter of setting it to listen for incoming packages in plain text?
Then there are the modules we use such as RFM9x and DRF127x that contain all the necessary antenna matching components for the appropriate frequency band.
So whilst you might be able to set a 434Mhz module to 169Mhz, the antenna matching would be all wrong and you might get very little signal through.
So is the general feeling that we won’t be able to receive this signal using SX1276 modules based on the Semtech reference design?
There isn’t a lot being done - especially re filtering - on the RX path (compared to TX) so while not optimal I was hoping we could get some signal through.
In normal circumstances (say if the module is in fact calibrated to this frequency) would we need a directional antenna to pickup these signals?
There isn’t a lot being done - especially re filtering - on the RX path (compared to TX) so while not optimal I was hoping we could get some signal through
Thats true, perhaps a 434Mhz module might let enough through.
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In normal circumstances (say if the module is in fact calibrated to this frequency) would we need a directional antenna to pickup these signals?
In normal circumstances ??
If we knew what the transmit power was and the LoRa modem settings, I could make a reasonable guess. I know what was needed for getting the FSK data back from $50SAT, and have done direct comparisons between that FSK data performance and LoRa. You could come up with an estimate by working through the dBs.
I believe Doppler shift is not a particular issue, although way back in 2015 I thought the fast moving Doppler shift as a satellite moves overhead might cause the LoRa to loose sync.
Maybe @telkamp could give us some more pointers and an indication of whether it is feasible for mere mortals.
I’ve been going from “this is way above my level of understanding” to “hmm, might be doable” (thanks to @jmarcelino) back to “ok, better forget about this, not something a noob like me can do” within a couple of days. And with such a small window of being able to test, receive the signal there is not much room for trial and error or to learn from others.
and only a few days to build a yagi and a satellite tracking system ect
