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M17 Reflector
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M17 abuse mitigations
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Test and verification dat...
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NONCE field
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M17 - SDR & GNU Radio
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Distinguishing between fr...
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TR-9 PCB, 4-layer
Forum: Technical
Last Post: SP5WWP
10-11-2020, 01:46 PM
» Replies: 2
» Views: 485

  M17 logo and a splash screen
Posted by: SP5WWP - 12-02-2019, 01:46 PM - Forum: General discussion - No Replies

As in the title - do we need a simple logo? Second question - i have prepared a splash screen for the TR-9 that is very basic. Link here: https://github.com/sp5wwp/TR-9/blob/mast...splash.raw The format is RAW, RGBA, 8/8/8/8.

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  Error Correction Coding
Posted by: SP5WWP - 12-02-2019, 11:01 AM - Forum: Technical - Replies (12)

I'm using a simple Hamming (7,4) now and apply it to every singly nibble. It obviously needs improvements. There is no bit re-ordering applied.
faydrus recommended using libcorrect (Reed-Solomon or convolutional coding). I can't run any of the example tests Sad

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Posted by: KE0WVA - 11-29-2019, 10:09 PM - Forum: General discussion - Replies (19)

Hello, my name is Stephan, I'm a radio amateur from Minnesota, USA. I have experience with electronics prototyping, some light embedded C programming, 3D printing, and PCB layout in kicad. I'm excited to contribute to this project any way that I can!

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  TODO list
Posted by: SP5WWP - 11-29-2019, 08:42 AM - Forum: Technical - Replies (11)

M17 standard:

  • a lot of brainstorming to make M17 well-fitted for hams
  • formalize the standard

TR-9 radio:
  • check doppler effect influence on reception
  • design a case
  • think about a version without a display (?)
  • remove 5V voltage regulator
  • dynamically change the clock, we don't need to run full 216MHz on idle

M17 repeater:
  • add power envelope control
  • finish telemetry website
  • add some more info on the front display

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  M17 frame description
Posted by: SP5WWP - 11-26-2019, 09:39 AM - Forum: Technical - Replies (65)

Still a subject to change!

Framing description and ECC scheme (ODF) https://m17project.org/files/download.ph...vxN5xvoFTA

Extract (stream mode):
[Image: BUtZ92V.png]

Frame generator for SDR (eg. HackRF), sends null data (TODO: fill it with Codec2 data):

GNU Radio Companion .grc file for M17 4FSK modulator with RRC filtering:

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  M17 hotspot with M17_ANL and Raspberry Pi
Posted by: SP5WWP - 11-26-2019, 09:34 AM - Forum: Technical - Replies (6)

An M17_ANL can be used with Raspberry Pi to make a hotspot. Why RPi? Because it's widely available, cheap and popular. Also, it has an Ethernet connector and can be programmed using Python, C - virtually anything.

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  M17 - SDR & GNU Radio
Posted by: SP5WWP - 11-26-2019, 09:32 AM - Forum: Technical - Replies (10)

M17 compatible radio built using RTL-SDR/HackRF and GNU Radio.

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Posted by: SP5WWP - 11-26-2019, 09:25 AM - Forum: General discussion - Replies (2)


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  TR-9 - schematics and firmware
Posted by: SP5WWP - 11-25-2019, 08:22 PM - Forum: Technical - Replies (1)

TR-9 is a handheld radio for the M17 system.

TR-9 schematic in PDF: https://github.com/sp5wwp/TR-9/blob/mast...nboard.pdf

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