Interesting, although using an already usability challenged platform like a cellphone to me isn't the best choice around. But I'm biased by having big fingers and some problems reading those small screens without my 2nd pair of glasses.<p>I'm still hoping the project below shows one day it's not a pile of vaporware.<p><a href="https://pocket.popcorncomputer.com/" rel="nofollow">https://pocket.popcorncomputer.com/</a>
> The schematics and PCB layout have not been released, so the OTG messenger is not an open-source hardware project yet, but Trevor says it may become open source if there’s enough positive interest from the community.<p>My disappointment is immeasurable.
On one of the example phone displays, you can see:<p>> Secure 4K encryption<p>I understand wanting to have some kind of peace-of-mind marketing statement, but encryption has everything to do with the chosen cipher suite and implementation, and while 4096-bit encryption can technically be called “4k” this furthers misconceptions around key size and strength [0]. This seems like another effort to borrow the marketing effect of 4K displays.<p>[0]: <a href="https://blog.cloudflare.com/why-are-some-keys-small/" rel="nofollow">https://blog.cloudflare.com/why-are-some-keys-small/</a>
This should link to <a href="https://github.com/TrevorAttema/OTGMessenger" rel="nofollow">https://github.com/TrevorAttema/OTGMessenger</a> and not to <a href="https://www.cnx-software.com/2021/07/09/nokia-e63-phone-converted-into-lora-messenger-for-secure-off-the-grid-communication/" rel="nofollow">https://www.cnx-software.com/2021/07/09/nokia-e63-phone-conv...</a><p>Or at very least, link to the original reporting on hackaday <a href="https://hackaday.com/2021/06/26/lora-messenger-in-nokias-shell/" rel="nofollow">https://hackaday.com/2021/06/26/lora-messenger-in-nokias-she...</a><p>(the hackaday link, at least, mentions another projects to convert cell phones into another thing: <a href="https://hackaday.com/2021/06/26/lora-messenger-in-nokias-shell/#comment-6360394" rel="nofollow">https://hackaday.com/2021/06/26/lora-messenger-in-nokias-she...</a>)
As kid who grew up in countryside I would love to have one of these to talk to my cousin as we didn't have computer or internet, the year was 2004 and we used to send tons of SMS but were always short on credit
What is the licensing issue with this? It is like Ham radio license ? Something else?
India has started banning drones outright and walkie talkies are banned unless you have prior police verification. I think they demand that radio exam, Morse and all but im not sure.
Where does this fit? Is it like cellular connection?
I'll be releasing the schematics when the codebase has been cleaned up and is stable. I also found a critical hardware bug in the LiPo charging circuit which could be dangerous so once the issue is fixed, I'll release the PCB.<p>There's no plan to commercialize the device. However, I hope that the hacker community will eventually help take the device to the next level through hardware and software enhancements.<p>Regarding voice... The board has a MEMS microphone linked to PWM and the STM32H7 has sufficient bandwidth to compress voice in real-time and package it ready for transmission. I plan to add short message voice transmission soon.<p>Regarding LoRa and LoRaWan... there have been suggestions to greatly improve range by piggybacking the things network. I'm investigating this. Currently, the network implementation is a simple self-healing mesh network. It features route discovery and low power performance. Standard Semtech LoRa drivers have been implemented with some important modifications to queue interrupts (better for low power management)<p>RF... the PCB features a tuned 915 mhz antenna + a microcoaxial RF connector for an external antenna. 50Ohm impedance tracing. <a href="http://www.farnell.com/datasheets/1867459.pdf" rel="nofollow">http://www.farnell.com/datasheets/1867459.pdf</a><p>PCB traces... 50 ohm impedance traces have been match length tuned for high speed NAND memory interfaces. Featuring a QuadSPI interface, the bus can operate at 160 mhz. While not super fast by todays standards, it's a nice feature.<p>4K encryption... It's not marketing hype or a play on 4K screens. I added incredibly strong encryption, just because it could be done. Fun to do and probably not needed... #overengineered<p>Nokia e71/72... the PCB can be EASILY adapted to suit those cases. I'm thinking about doing it. Anyone like to assist?<p>Operating system... I'm using FreeRTOS as the kernel with custom device drivers for scattered throughout the codebase to handle the keypad, RTC, LoRa radio, LCD screen tearing, USB port, MicroSD card etc.<p>Debugging and development enhancements... I plan to 3D print a chassis to hold the phone when debugging. For this to work, the PCB needs to have pads placed strategically around the battery area so that when it's docked, the SWD debug header, trace pins and power sources are exposed to the debug chassis pins. Next PCB version.<p>If you have any questions.... shoot. I'm happy to discuss the device here on the forum. If you have collaboration ideas, I'm open to hearing them.<p><a href="https://github.com/TrevorAttema/OTGMessenger" rel="nofollow">https://github.com/TrevorAttema/OTGMessenger</a>