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> 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. My disappointment is immeasurable.
The author doesn't owe you anything though.
> Secure 4K encryption
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.
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?
There's different types of regulation to consider.. There's spectrum licensing, radio user licensing, and product certification. 2.4 GHz is considered an ISM band meaning it's license free meaning you do not have to purchase a license from the government to use that physical chunk of spectrum. There are certain chunks of spectrum (frequencies) that are auctioned off by the government. This gets you exclusive usage to…
This is not necessarily true: some governments demand that ISM frequencies be used for Industrial, Scientific and Medical purposes only, so it is not license-free for personal use in all jurisdictions.
It would be great if you could do voice via LoRa too but that would probably quickly exceed the duty cycle restriction.
Earlier quoted context omitted.
At least with the company I'm at, I'm supposed to talk to my boss before releasing code from side projects.
Sounds like slavery or indentured servitude. Why do you accept it?
Or at very least, link to the original reporting on hackaday https://hackaday.com/2021/06/26/lora-messenger-in-nokias-she...
(the hackaday link, at least, mentions another projects to convert cell phones into another thing: https://hackaday.com/2021/06/26/lora-messenger-in-nokias-she...)
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.
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.
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)
RF... the PCB features a tuned 915 mhz antenna + a microcoaxial RF connector for an external antenna. 50Ohm impedance tracing. http://www.farnell.com/datasheets/1867459.pdf
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.
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
Nokia e71/72... the PCB can be EASILY adapted to suit those cases. I'm thinking about doing it. Anyone like to assist?
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.
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.
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.
Earlier quoted context omitted.
Sounds like slavery or indentured servitude. Why do you accept it?
Because it was otherwise significantly better than my previous situation? A better question is "why is this legal?"