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grupacosmo / cansat

Bare-metal software for the sounding rocket payload.
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Ground Station for Cansat 0.2 / Rocket #74

Open vanderAries opened 1 year ago

vanderAries commented 1 year ago

Here is a simple graph of my idea about Ground Station, that allows 2 way communication with Cansat or rocket + possibility to listen live data all the time.

We will need 2 pairs of LoRa.

1 Pair will be like in Cansat 1.0, for constantly sending data from Cansat and receiving it on ground:

image

2 Pair will be for 2 way communication. Ground station could send commands to Cansat/Rocket e.g. deploy parachute, and receive confirmation of successful action. It could look like this:

image

vanderAries commented 1 year ago

If we stick with LoRa E5, only way to use P2P is with TEST mode. This mode doesn't have any security built in, even showing ID of the device that is sending the message. Anybody who is listening on the same frequency could easily receive a message with command, copy that message and send it again. Adding own ID in the beginning of message is not helpful, because it could be copied too.

In that case, we should add some encryption and authorization. Unfortunately I'm not familiar with that topic, but a very basic idea of how this could be resolved is below:

image

This will require some decoding mechanism with common algorithm for both: Cansat and Ground Station. Also records of previous keys on Cansat side. But probably there are a lot of better ways to secure that, all ideas are welcome.

Bartosz-Slowik commented 1 year ago

We can find a better module fitting out needs, but i think it will have simmilar problems. Feel free to research this.