11–20 of 25 posts
Was looking into Meshtastic recently, as a means to have basic communication in disaster situations (hurricanes, war, etc.) but haven't picked a device yet. Any recommendations?
For more portable use, you might go with something like a Lilygo Meshtastic T-Echo.
https://www.ebay.com/itm/186858359561?mkcid=16&mkevt=1&mkrid...
Note that the RP2350, being M33 based has square root, and can add 16MB of PSRAM behind the XIP that will help with the flash writing problem, The solder party RP2350 Stamp XL has a SOP8 pad to add PSRAM and is actually shipping for anyone who is looking to play with them, no connection with them, just a user.
The extra PIO block would also allow for S2C output which may be nice rather than a TPA2012D2, which will require most people to buy a breakout board anyway.
The rp2040/rp2350 series is incredible. The DMA/SIO/PIO features are just so powerful and even the esp32/stm32 seem restrictive to me to go back to. It is amazing what people are doing with them.
Was looking into Meshtastic recently, as a means to have basic communication in disaster situations (hurricanes, war, etc.) but haven't picked a device yet. Any recommendations?
Very nice. It's not a "crystal radio", though. It's a direct sampling receiver. That is, the processing takes place at the RF frequency directly. Most receivers use heterodyne conversion to down-convert a desired chunk of spectrum to a convenient working frequency. This doesn't. It just runs the raw RF through an A/D.
As A/D devices and processing have improved, the frequency upper limit for direct conversion receivers has moved up. There are low-cost direct conversion receivers going up to 50MHz, but they have to use an FPGA rather than doing all the work in software.
Was looking into Meshtastic recently, as a means to have basic communication in disaster situations (hurricanes, war, etc.) but haven't picked a device yet. Any recommendations?
When I look at that crystal radio kit, my fingers hurt. I had a kit like that as a kid in the 90s - not sure if it was a radio or more generic electronics - with the springs to hold wires together. At some point, made a short circuit and burned my fingers. Immediately upon seeing that, the memory comes back. I guess it's burned into my memory.
When I look at that crystal radio kit, my fingers hurt. I had a kit like that as a kid in the 90s - not sure if it was a radio or more generic electronics - with the springs to hold wires together. At some point, made a short circuit and burned my fingers. Immediately upon seeing that, the memory comes back. I guess it's burned into my memory.
For any powered circuit though, a few AAs can dump a surprising amount of current and heat into naive fingers.
(2023) Very nice. It's not a "crystal radio", though. It's a direct sampling receiver. That is, the processing takes place at the RF frequency directly. Most receivers use heterodyne conversion to down-convert a desired chunk of spectrum to a convenient working frequency. This doesn't. It just runs the raw RF through an A/D. As A/D devices and processing have improved, the frequency upper limit for direct conversion…