Meshtastic

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A community to discuss Meshtastic (https://meshtastic.org/docs/introduction)

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Sal@mander.xyz

ponderings (lemmy.zip)

submitted 5 months ago* (last edited 5 months ago) by shortwavesurfer@lemmy.zip to c/meshtastic@mander.xyz

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So I just saw a video where somebody made a bulletin board system over the mesh like it's fucking 1999 or something and it got me thinking Would it be possible to send web pages over the mesh as long as they were small?

I went to the DuckDuckGo homepage and copied its HTML source code into a text editor and found out it was something like 46,000 characters and with a 288 character limit it would take 145 messages to send that across. Each message would be something like 0.69% of that page.

It doesn't seem impossible, but you would have to make your pages very lightweight like they were in the 1990s in order to do it efficiently.

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[–] Sal@mander.xyz 3 points 5 months ago* (last edited 5 months ago)

In the radio settings page of the Meshtastic docs they describe the maximum speed of transfer for different setting combinations that have been tested. The fastest setting is the Short Range / Turbo, which can achieve up to 21.88 kbps: https://meshtastic.org/docs/overview/radio-settings/

The more common "LongFast" setting achieves 1.07 kbps. I just saved a few simple text-only HTML sites and they weight about ~2 - 5 kb, so it would certainly be possible to transmit them in a few seconds. There is some additional overhead with every packet, and in the EU at least we have a 10% duty cycle rule a 868 MHz, so only 6 seconds of every minute should be used for transmitting. Navigating through the page would be a bit cumbersome.

Since the html page will exceed the character limit from the Meshtastic app chat, it would probably make sense to make use of a dedicated app to send these kind of packets using LoRa instead of Meshtastic itself.

There are other methods of sending IP/TCP packets over packet radio. I am just now learning about this, and found this video yesterday: https://youtu.be/V0FAzMIsxMg?t=1413

With this technique you can use a radio to transmit packets to a Linux PC that behave just like an 'Ethernet' TCP packet. The video covers a related open source implementation called 'New Packet Radio' with which you can transfer 50 kbps - 500 kbps using radio packets in the 430 MHz band. These protocols work with frequencies and powers generally reserved for those with a HAM radio license: https://hackaday.io/project/164092-npr-new-packet-radio