We have finally secured our presence at DEFCON. Well, kind of. The CSI CS7000-M17-Plus running OpenRTX is currently being showcased at the venue by Arthur N4TRQ. Here’s a few photos:
Thank you very much for spreading the word at such a significant event! Photos courtesy of hacker.house.
Our work on OpenRTX port for the Retevis C62 progresses. Don’t worry about the LinHT – our efforts are allocated there as well!
This hardware platform is getting a special treatment, as it can be used both as one of a valid OpenRTX targets and a carrier for the LinHT board. Porting OpenRTX will bring M17 mode to C62 users without the need to modify anything. Just flash the radio and go. Very simple stuff.
LinHT, on the other hand, still remains dedicated to skilled hams. The bar is set high, but not intentionally – LinHT is still being developed. When the time comes, the bar should lower considerably. The replacement boards would become available along with the Yocto Linux image incorporating basic analog FM/M17 support (“batteries included”). In the future, LinHT could be treated as a standalone OpenRTX target as well.
LISTENAI’s cskburn is the tool used to flash the C62. It also flashes the DSP firmware, as it uses a separate binary. Recently, we have spotted a bug in the tool’s version 1.31.0. The bug affects the internal argument parser and makes it impossible to set start and stop addresses using the –read argument’s parameters.
A pull request has been offered. For now, it is best to use our fork for flashing (or an older version, probably the 1.25.0 – right after Andreas’ OE3ANC fix was merged).
A great write-up covering C62 flashing process details curated by Vlastimil OK5VAS is available here.
LabCat (Tobias DL3MHT) uploaded his interview with the LinHT development team: Wojciech SP5WWP, Vlastimil OK5VAS, and Andreas OE3ANC. Check it out 🙂
Our team spent three amazing days at the HAM Radio Friedrichshafen event. We had a real lot of traffic. Thank you for stopping by and for all the questions that you had! Big shout out to DARC guys, especially Jann Traschewski DG8NGN, for providing space for our booth.
M17 Foundation attendees:
OpenRTX booth:
Before Friedrichshafen, we want to put the current LinHT development status in one place. We have published many short updates over the last months, and the project moved through several phases: Rev A proof-of-concept testing, Rev B design, manufacturing, first boot, RF tests, audio bring-up, GNSS debugging, and now Rev C planning.
This post summarizes that progress. It starts with what Rev A proved, then goes through what we changed in Rev B, how we built the first boards, what worked during testing, what failed, and what we need to fix before Rev C.
If you want the longer background, start with my older text about the first LinHT prototype: LinHT – Open SDR Handheld for Radio Amateurs. That article describes the Rev A board, the Retevis C62 donor-radio approach, and the basic idea behind LinHT: a Linux-based SDR handheld transceiver, open enough that the radio can be changed in software, not only programmed from a vendor tool.
Rev A was our proof of concept. It showed that the architecture made sense and that the device could work the way we imagined. An i.MX93 system-on-module could boot Linux inside a handheld radio body, run a Yocto image, expose USB networking, talk to the display, run GNU Radio flowgraphs, and use the SX1255 IQ RF front end. We decoded M17, tested TETRA receive, displayed spectrum data on the small screen, and ran enough hardware and software tests to be sure that the concept was valid.
Rev B is the revision where we tried to turn that proof of concept into a much more complete handheld.
(more…)Vlastimil OK5VAS recently tested the GNSS module. Unfortunately, the module used (Quectel LG77L) does not obtain a fix, even when enabled for 30 minutes, outdoors.
The most suspicious part, and likely culprit, is the path between the antenna and the module:
When measured, S11 (from the GNSS module’s perspective) looks like this:
Many thanks to Martin OK1WPM, who helped measure the antenna path both with the cover removed and with the chassis held in place.
A quick ad hoc fix before Friedrichshafen ham fair is to place an additional capacitor along the coplanar waveguide:
Some more experimentation is required. Keep your fingers crossed! See you in Germany!
News from Tom, N7TAE:
Version 1.4.2 of mvoice is now available. It pulls the https://m17-project.github.io/hostfiles/M17Hosts.json file to initialize the reflector selection drop-down menu. A GIANT Thank You to Jim N1ADJ for setting this up!
More details: https://github.com/n7tae/mvoice
It took us some time, but here’s a quick update on where we’re at with the LinHT Rev B hardware tests:
New, M17-related functions include:
More info: https://github.com/OpenRTX/OpenRTX/releases/tag/v0.4.4
