Meshtastic

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

Other mesh communities:

MeshCore: !Meshcore@feddit.org Reticulum: !Reticulum@mander.xyz

founded 2 years ago

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GitHub - RCGV1/Meshtastic-SAME-EAS-Alerter (github.com)

submitted 1 day ago* (last edited 1 day ago) by IcedRaktajino@startrek.website to c/meshtastic@mander.xyz

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I have an RTL-SDR tuner that has been begging for a use, and I may have just found it.

Update: Got a prototype setup on my laptop. Letting it run to see if I can catch a test alert to see if it gets passed to the mesh. Then gonna try to deploy it to a PiZeroW2. Also plan to tee the output to an Icecast sender so other devices on the network can listen to the weather reports. Right now, it's piped to a player to listen to it on the laptop.

Update 2: Managed to catch a weekly test, and it picked it up and forwarded it. Nice. The only problem was the mesh "ate" the first message. Might just be that node I'm using as it's always been problematic using it over TCP/WiFi (the USB-serial chip is broken in this one). So next step is to package this up in a PiZero2W. (Confirmed that specific node is just wonky. Hooked a node up direct to USB and all message parts were successfully received).

Update 3: If you want to test the setup without having to wait for a weekly test, you can download a sample SAME audio clip from Wikipedia (https://en.wikipedia.org/wiki/File:Same.wav). You'll need to convert the sample rate before you can use it, though.

$ ffmpeg -i Same.wav -ar 48000 same48.wav
$ cat same48.wav | Meshtastic-SAME-EAS-Alerter --test-channel 0
2026-04-02T15:32:31.172Z INFO  [Meshtastic_SAME_EAS_Alerter] Successfully connected to the node.
2026-04-02T15:32:31.175Z INFO  [Meshtastic_SAME_EAS_Alerter] Loaded locations CSV
2026-04-02T15:32:31.175Z INFO  [Meshtastic_SAME_EAS_Alerter] Monitoring for alerts
2026-04-02T15:32:31.175Z INFO  [Meshtastic_SAME_EAS_Alerter] Alerts will be sent to channel: 0
2026-04-02T15:32:31.175Z INFO  [Meshtastic_SAME_EAS_Alerter] Test alerts will be sent to channel: 0
2026-04-02T15:32:31.201Z INFO  [Meshtastic_SAME_EAS_Alerter] Begin SAME voice message: MessageHeader { message: "ZCZC-EAS-RWT-012057-012081-012101-012103-012115+0030-2780415-WTSP/TV-", offset_time: 47, parity_error_count: 0, voting_byte_count: 69 }
2026-04-02T15:32:31.201Z INFO  [Meshtastic_SAME_EAS_Alerter] No location filter applied (locations empty) or no locations in alert
2026-04-02T15:32:31.201Z INFO  [Meshtastic_SAME_EAS_Alerter] Attempting to send message over the mesh: 📖Received Required Weekly Test from WTSP/TV, Issued By: Broadcast station or cable system, Locations: Hillsborough, Manatee, Pasco, Pinellas, Sarasota
Connected to radio
Sending text message 📖Received Required Weekly Test from WTSP/TV, Issued By: Broadcast to ^all on channelIndex:0 
Waiting for an acknowledgment from remote node (this could take a while)
Received an implicit ACK. Packet will likely arrive, but cannot be guaranteed.
Connected to radio
Sending text message  station or cable system, Locations: Hillsborough, Manatee, Pasco, to ^all on channelIndex:0 
Waiting for an acknowledgment from remote node (this could take a while)
Received an implicit ACK. Packet will likely arrive, but cannot be guaranteed.
2026-04-02T15:33:11.227Z INFO  [Meshtastic_SAME_EAS_Alerter] End SAME voice message
2026-04-02T15:33:11.251Z WARN  [Meshtastic_SAME_EAS_Alerter] Program stopped, no longer monitoring

Working Prototype

$ rtl_fm -f 162.400M -s 48000 -r 48000 | tee >(play -q -r 48000 -t raw -e s -b 16 -c 1 -V1 -v 4 - sinc 125-3.2k) >(Meshtastic-SAME-EAS-Alerter --host 192.168.1.236 --test-channel 0) > /dev/null

Found 1 device(s):
  0:  Realtek, RTL2838UHIDIR, SN: 00000001

Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
Tuner gain set to automatic.
Tuned to 162652000 Hz.
Oversampling input by: 21x.
Oversampling output by: 1x.
Buffer size: 8.13ms
Exact sample rate is: 1008000.009613 Hz
Sampling at 1008000 S/s.
Output at 48000 Hz.
2026-04-02T14:20:49.702Z INFO  [Meshtastic_SAME_EAS_Alerter] Successfully connected to the node.
2026-04-02T14:20:49.704Z INFO  [Meshtastic_SAME_EAS_Alerter] Loaded locations CSV
2026-04-02T14:20:49.704Z INFO  [Meshtastic_SAME_EAS_Alerter] Monitoring for alerts
2026-04-02T14:20:49.704Z INFO  [Meshtastic_SAME_EAS_Alerter] Alerts will be sent to channel: 0
2026-04-02T14:20:49.704Z INFO  [Meshtastic_SAME_EAS_Alerter] Test alerts will be sent to channel: 0

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[–] Turret3857@infosec.pub 3 points 1 day ago (1 children)

This looks cool asf. I wish I could have enough time in the day to set something like this up.

[–] IcedRaktajino@startrek.website 3 points 1 day ago* (last edited 1 day ago) (1 children)

Definitely one of the "throw it on the pile" projects for me, too, but I'm for sure throwing it on the top of the pile. Have had quite a few severe storm warnings this year already and this could be pretty useful. I was originally just looking for a way to forward NWS/EAS alerts to Meshtastic from the internet, but getting them direct over-the-air is even better.

Only complicating factor is I have to fashion or buy an antenna for ~150 Mhz since I don't have any adapters that will fit the RTL-SDR (I've just used the little stock UHF TV antenna that came with it for ADS-B and other playing around).

[–] Turret3857@infosec.pub 2 points 1 day ago (1 children)

If you don't mind, would I be able to pick your brain? I'm trying to get into meshtastic but I'm kind of confused on where to start. I have a couple ESP32s, and I know I need some sort of lora radio for them. Do you have any good starter guides/resources?

[–] IcedRaktajino@startrek.website 2 points 1 day ago* (last edited 1 day ago) (1 children)

Most of what I've dealt with were ESP32-based devices like the Heltec V3 (now V4) that have integrated LoRa radios. It should be possible to add on a SX1262 LoRa radio via SPI and flash Meshtastic firmware, but most people just start with a pre-built kit since they're pretty inexpensive and have battery charging circuitry and everything already onboard (which you'd otherwise have to handle yourself with a vanilla ESP32).

I started with the Heltec V3, and the V4 improves several gripes I had with it. They're easy to get started with, lots of case designs available, and generally good entry points.

SeeedStudio has a lot of pre-built options as well. My new daily driver is the SenseCap T1000e which is about the size of a few credit cards stacked together. Posted about it here: https://startrek.website/post/34105873

There's two main flavors of Meshtastic devices: ESP32-based and nRF-based. The former are generally a little less expensive and have WiFi but are a lot more power hungry.

The nRF-based ones are more power efficient and can run longer from smaller batteries. The tradeoff is those only have Bluetooth and lack WiFi. I don't really use WiFi with these, but it can be useful if you want to connect a node to MQTT.

Check out Seeed to see some of their pre-made options: https://www.seeedstudio.com/LoRa-and-Meshtastic-and-4G-c-2423.html

[–] Turret3857@infosec.pub 2 points 1 day ago (1 children)

Oh wow! I was not aware how inexpensive pre-builts were. I may just pick one of those up then. Thank you for the link!! Is there any benefit of having nodes connected to MQTT? Ive heard theres some smart-home applications for people with acres of land, but would you say theres a usecase for people who live in an apartment or in.the suburbs?

[–] IcedRaktajino@startrek.website 2 points 1 day ago (1 children)

I don't use MQTT currently, but there's several things you can do with it:

Pass some messages as plaintext for use in, say, HomeAssistant
Bridge meshes over the internet
Send/receive ProtoBuf messages from an MQTT client to the Meshtastic node and the mesh
Plugging in some of the mesh mapping programs to visualize the mesh

I tried setting up MQTT with HomeAssistant but couldn't get messages to come in correctly. Most likely my own fault but I just never got back to it as I didn't have a specific need in mind when I was setting it up.

[–] Turret3857@infosec.pub 2 points 1 day ago

Bridge meshes could be interesting. Like if I could convince a friend to get one as well, then we could use meshtastic when were nearby each other or miles apart.

MQTT is kind of a PITA to get working. I had to use MQTT-Explorer to figure out a proper configuration. It seems since then, the developer has started using Copilot to write and test the application.