Companion board questions

[Kurt V.]

Hi all, 

I have a few questions about the companion board. 

1. Is VAC still used when we add the companion board? If not, if not, will it eliminate any VAC underflows/overflows forever, right? 

2. When using the companion board and upgrade the hermes lite 2 to the plus version, will the equalizer and CFC equalizer still have any effect? 

3. Can you still chose to have a audio output to the computer speakers, or will all audio output be routed only to the speaker output of the companion board? 

Sorry for my ignorance. I couldn't find much information regarding the companion board. 

[G4ZAL]

Look here for the general proposal(s) for the N2ADR companion board.

https://github.com/jimahlstrom/HL2IOBoard

Nigel

G4ZAL

[Ed Grafton]

I think he is referring to the HL-2+ companion board. Not Jim's board.

This page should lead you where you need to ask.  Hermes Lite 2 Plus

Ed

[Steve Haynal]

Hi Kurt and Other New HL2 Owners,

The AK4951 companion card topic is a bit of a sore topic for me. There was an acrimonious split several years ago. Search this list for "ak4951", "audio codec" or "local audio" if you want more information. Since there are so many new HL2 users, and some (uninformed in my opinion) buzz going around recently, it may be helpful to share my perspective about this companion card. This is based on my build, test and use of an early version of this card, as well as the original openhpsdr Hermes from which it was derived. I intentionally removed this local audio functionality when designing the Hermes-Lite 2 for these reasons:

* The functionality it adds is not available for remote use of the HL2. One must operate very near the HL2 to make use of this audio and CW functionality. I don't like this "split-personality" and find it easier for support and remote operation if everyone uses audio through the host computer.

* It is a custom and expensive 48kHz 16-bit networked sound card. Computer software is not eliminated and is still required for processing the audio data. Take a look at the USB_protocol_V document on the protocol wiki page:

https://github.com/softerhardware/Hermes-Lite2/wiki/Protocol

Audio samples from the microphone are sent back to the computer, processed by the software, and then IQ is sent to the HL2 for transmit. This adds latency. It does not eliminate latency as suggested by some and is nothing more than a networked sound card. You have a much more generic, reusable, flexible and software-oriented solution if you invest in a good sound card with multiple types of microphone inputs and properly setup ASIO, WASAPI drivers. Latencies above 10ms are typically not noticeable to humans, and a good sound card setup can easily do much less than that. 

Here is the sound card I use:

https://usa.yamaha.com/products/music_production/interfaces/ag_series/index.html

* Support for the audio transport uses scarce FPGA resources and pins. You may not have 4 receivers in gateware which supports this companion card. Some of the header pins used by this companion card were intended to synchronize multiple HL2s for coherency and diversity, so you lose that optional functionality.

Since designing the HL2,

* Not all software supports transfer of audio to and from the HL2. Unless there are updates I am unaware of, SparkSDR, SDR Console, and Quisk support is for the HL2 and do not support audio over ethernet.

* AH-4 Tuner and HR50 support already exist in the stock HL2:
    https://github.com/softerhardware/Hermes-Lite2/wiki/docs/HL2HR50.pdf
    https://github.com/softerhardware/Hermes-Lite2/tree/master/hardware/enclosure/endcaps/kf7o/hl2_40b#atu

* This companion card does have very low CW sidetone latency as the sidetone audio is mixed in on the FPGA with the delayed audio from the host. But there are stock HL2 CW users who are happy, especially with how SDR Console implements CW. Many others just use a keyer with sidetone. We created a novel CW keyer to specifically address CW sidetone latency but still allow for remote location of the HL2. In my opinon, this is a more interesting "software-defined" solution for a software-defined radio. I chose not to productize this as I did not want to take on the anticipated support and time commitments, but it is entirely open software and hardware if someone would like to take on the project.

https://github.com/softerhardware/CWKeyer

There are also strategic reasons why I do not support this companion card:

* The PCB design is not open source, even though it is based on and derived from open source. This is the same garbage we see from Apache Labs where they take an open source design, create a proprietary PCB, and essentially kill the open source nature of the project.

* Even though there were and are clear objections, the main project organizer continues to use "Hermes-Lite 2" in the project name. (There were no objections when I added -Lite to the original Hermes project.) Imagine if someone started selling packets to sprinkle in your Coca-Cola and called it Coca-Cola+... 

* The original agreement was for any gateware changes to be pushed back into the main repository under the ak4951 variant and any gateware files to be hosted on the github site. Recently, that has been broken by hosting on their own web site. This just makes a further mess of the Hermes-Lite 2 project, and breaks any detante that was established.

* The AK4951 is not available from reputable source. There was a fire which burned down the factory in 2020:

https://www.strata-gee.com/akm-fire-update-3-yet-another-step-towards-recovery-co-launches-new-flagship-chip/

Since then, AKM has had to find other fabs for only some of its products. They have focused on newer products and not the AK4951. It is difficult to find the AK4951 and all availability is from leftover excess or seconds. PCB assembly houses, even in China, will steer away from this type of stock given past problems. My understanding is that one person assembles all boards in their garage in the US from parts purchased on AliExpress. This is not a scalable solution.

I have probably ranted on long enough. The HL2 is a completed project. There are no plans to ever make an "official" audio codec board under any circumstances. So, if you really want one, you need to contact the other group. Taka, JI1UDD, is the most technically proficient one there and can answer technical questions. He did more than just create a PCB. He ported and modified the RTL from the Hermes project. He created an original design around the AK4951. He created the original PCB.

73,

Steve

kf7o

[Ezio Insinna]

Hi Steve,

Thank you very much for your extensive explanations concerning the HL2+ companion board.

Some of us are surely tempted by it, but I in intuitively thought it was an unnecessary extension. Your mail has definitely convinced me NOT to buy and install it.

I'm very happy with the original....

Kind regards

73

Ezio

F5MWA / K3EK

--
You received this message because you are subscribed to the Google Groups "Hermes-Lite" group.
To unsubscribe from this group and stop receiving emails from it, send an email to hermes-lite...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/hermes-lite/6e155b2e-7bae-4668-9eab-a44545896d12n%40googlegroups.com.

[Simon Brown]

With latest WASAPI even in shared mode a latency of < 3ms is possible when processing the microphone. I am in 100% agreement with you.

Simon Brown

https://g4eli.com

https://sdr-radio.com

---

From: herme...@googlegroups.com <herme...@googlegroups.com> on behalf 

[Ron Lewkowicz]

I  think for the extra I/O the new board being worked on now is probably more worthwhile.  I don't CW so can't say if having the HL2+ can make a world of difference there.  For audio processing I've never understood why you would want this.  Not being limited by onboard audio is a huge plus for the HL2. 

[radi...@mail.com]

Hi Steve

Our huge loss that the CW Keyer project never made it to Makerfabs even if it was made 100% clear that it would not come with any support. I for one would have bought it. Don't really have the capacity to make one myself, although I'm still quite tempted to give it a go to see if I can. It was an inspired design and perfect companion to add to the Makerfabs HL2 lineup! I wonder if you would ever reconsider taking it through to production, as I say, on the full understanding that zero support would be offered?

100% agree with all you said about the HL2+. IMHO misses the whole point of the HL2 project philosophy. Plenty of other "local" radios out there if you really want that sort of thing and netbook or rejuvenated spare laptop an easy companion to operate locally in the field with no need for the HL2+ board.

73

Max

On Thursday, 3 August 2023 at 05:56:07 UTC+1 softerh...@gmail.com wrote:

Hi Kurt and Other New HL2 Owners,

We created a novel CW keyer to specifically address CW sidetone latency but still allow for remote location of the HL2. In my opinon, this is a more interesting "software-defined" solution for a software-defined radio. I chose not to productize this as I did not want to take on the anticipated support and time commitments, but it is entirely open software and hardware if someone would like to take on the project.

https://github.com/softerhardware/CWKeyer

73,

Steve

kf7o

[Jaroslav Škarvada]

It would be great if somebody experienced with Makerfabs and the
logistic stuff could organize group buy (without additional support). In
such case I would be interested in at least one keyer

73! Jaroslav, OK2JRQ

radi...@mail.com napsal(a):

> --
> You received this message because you are subscribed to the Google
> Groups "Hermes-Lite" group.
> To unsubscribe from this group and stop receiving emails from it, send
> an email to hermes-lite...@googlegroups.com

> <mailto:hermes-lite...@googlegroups.com>.

> To view this discussion on the web visit

> https://groups.google.com/d/msgid/hermes-lite/642485ec-e039-4e44-9816-5bc51d80d951n%40googlegroups.com
> <https://groups.google.com/d/msgid/hermes-lite/642485ec-e039-4e44-9816-5bc51d80d951n%40googlegroups.com?utm_medium=email&utm_source=footer>.

[Ron Lewkowicz]

I have electric guitar that I plug into USB audio interface and use Guitarix to simulate tubes,  effects and Impulse Response cabinet emulation.  It does all this with no perceivable latency.  I'm not sure why CW can't be done in software SDR with at least that low of latency.  Does a couple ms latency really throw one off on CW?

[KP4RX - Ramon]

Even though learning CW has been on my personal goals for a while I haven't learned yet. With that been said, I was looking into the keyer myself as an extra motivation on starting to learn CW and having more excuses to play with my stock HL2 (Not that I need more excuses! lol). I enjoy building kits and electronics on my scarce spare time, but the cost of building just 1 unit is not justifiable for me as a "toy that I still can't really use". If there is such interest from a couple forum members and we get to a number that makes the build affordable I can take care of ordering the PCBs and putting together some of them for those who don't know or want to build them and bundle kits for those who prefer building them. I would do this as a hobby sidekick with absolute zero interest in monetization (Besides getting my own cheaper by leveraging bulk order), just my 2 cents on paying it forward to this great open source project, obviously those interested would need to cover parts and shipping cost. If you guys are interested let me know and we can arrange something.

73 de KP4RX

[Jaroslav Škarvada]

This sounds great, count with me, now I am interested in 2 keyers :) Kit
(PCB + parts) is OK for me, I like building kits :). Regarding morse
code learning I would recommend Morserino-32 [1, 2], it's open source
and really great

73! Jaroslav, OK2JRQ

[1] http://www.morserino.info/
[2] https://www.eham.net/reviews/view-product?id=14239

KP4RX - Ramon napsal(a):

> https://groups.google.com/d/msgid/hermes-lite/cac145d0-6961-4807-8abe-1872665de7fcn%40googlegroups.com
> <https://groups.google.com/d/msgid/hermes-lite/cac145d0-6961-4807-8abe-1872665de7fcn%40googlegroups.com?utm_medium=email&utm_source=footer>.

[radi...@mail.com]

Just to clarify, the idea of this interface is not just a keyer. If you simply wish to work CW with the HL2 local to your operating position you can use regular keyer with (if software does not cater) local sidetone.

CW with SDRs sounds very simple but it's anything but. The simplest mode for most conventional analogue transceivers becomes the most tricky when it comes to SDRs! Yes, a few ms (granted quite a lot more than 2 or 3 ms can be tolerated) can be very off-putting especially when keying at higher speeds (25 wpm +). Anyway, there is latency inherent in any SDR, so it's impractical to do what many would do with an analogue rig and simply open up the RX front end slightly to listen to the actual (attenuated) TX signal. Instead you must rely on sidetone, either locally generated or in the software. Your mention of guitar via amp simulator is akin to the software providing the sidetone. SDR Console does this with latency adequate for up to perhaps about 30wpm. SparkSDR also provides sidetone. I do not know what the speed limitation is (if any). By far the easiest way around all of this is a keyer generated sidetone but then you slightly miss the luxury of perfectly netting the TX tone frequency on to the received station as you can with SDR Console for example. But that's no real issue I guess. In my experience of CW operators syncing tone frequency, relatively few people manage it!

Anyway, all of this is missing the point somewhat with ref to Steve's remote keyer. The whole point of HL2 is it is a networked radio. So all operations should be achievable over the network, be it your local LAN or a far away remote location. So idea of Steve's "Teensy Keyer" project is to be able to key the HL2 when it's located remotely at some distance away, while not worrying about latency of sidetone etc., so keys the TX over network, not via the front panel key jack that we might normally use for local operation. Not only that, but also serves as a standalone audio interface to which you can attach mic and speakers/headphones, so it makes the HL2 a complete "remote package" so to speak with no use of the PC soundcard.

All details here:

https://github.com/softerhardware/CWKeyer

Hope that helps to clarify what this interface does and achieves over and above a regular keyer like Winkeyer etc.

73

Max

[radi...@mail.com]

I realise his has perhaps gone off-topic a little (or then again perhaps not), but here's picture of Steve's Teensy keyer for those that have not seen it. "A picture paints a thousand words", as they say. Should also have attributed the inputs from several others to the project like Jim N2ADR for example. Others too. Sorry, I don't recall exactly who else has had direct input, no offence intended.

Max

[Rick Langford (N8SDR)]

Steve, I wish I had seen your response and reasoning of why not to support it,

Before I had already done so, as a new HL2 user and all the new BUZZ around it and the "**unmentionable" bitten the bait and got hooked!

I feel bad now knowing more details and also feel suckered by advertised features, (But hey that what ads do lure you in take your money then leave you flustered and feeling abused)

ESP lately after a few email exchanges with the mentioned parties, only to find out there not even using the software suggestions listed on their website and telling others to use.

Which is why of course they never saw the issues I pointed out about the combination of using an HR50 and incorrect band LPF in Beta 3 being used causing UNK errors-

I was simply told they don't happen, and they tested it, of course I ASSUMED said Indvidual was using the software they linked and suggested, Oh my bad! again, why would one assume the builder/supplier etc. is using something different than what they list as suggested on their website. 

So please forgive me- I will be removing said **Unmentionable: and yes, I saved the FB28 to restore it as was.

[Steve Haynal]

Hi All,

Sorry for the late replies. I only catch up on HL2 stuff once or twice per week now. My main (reduced) focus now is to help with any hardware problems, handle a few repairs, and then with my learnings from those two activities help Makerfabs reduce any problems with shipped units, so I often don't read every post carefully.

No need to apologize for using the companion card. There are some people who really like the idea. I have just always been a proponent of doing more with software when possible even if it does require a bit more setup.

Regarding the CW keyer with audio interface, the challenges that remain are:

* Some additional hardware testing is required, as well as minor changes to the BOM and PCB layout

* There are 3 versions of firmware that run on the keyer! I have my k3ng port which I dropped to try and reduce the confusion around which firmware to use. Both Roger AD5DZ and Christoph DL1YCF wrote firmware with interesting unique features. Maybe it is a good problem to have, but one must manage this flexibility somehow.

* The firmware can't be built with the standard Teensy libraries. We found and fixed bugs in the USB audio code, as well as added support for 48kHz. I tried several times to push my changes to the main repository but never heard back from Paul. I suspect that since my changes are only for newer Teensy models, it complicates integration and support for all Teensy models.

* Documentation, videos, support, etc. is needed. I barely find the time now to handle hardware problem reports. Furthermore, I am not a CW nor SSB user (long live QRP digital modes!) so actually have little interest in using this project. I'd rather spend my time on other things which interest me more (and which are much more esoteric) than on support for this project. So other people would have to step up to support and fully take on this project.

I have two of these CW keyers with audio interface that I will ship free of charge to people who convince me and this group that they will not just use the keyer for themselves, but push the project forward. Also, I sent out 8 keyers to the main software developers about a year ago. If any software developers are not using the keyer and willing, I will use funds from the R&D pool to ship keyers to other people willing to push the project forward.

Makerfabs knows how to make the keyer. They made an initial batch of 10. There are few things to cleanup, but I am sure Makerfabs would be willing to make more.

73,

Steve

kf7o

[Rick Langford (N8SDR)]

Id  like to see this revived

Although I'm not a great or avid cw user.

I think it would be of interest to many esp those doing remote and qrp set-up.

Get Outlook for Android

---

From: herme...@googlegroups.com <herme...@googlegroups.com> on behalf of Steve Haynal <softerh...@gmail.com>
Sent: Sunday, August 6, 2023 3:15:36 PM
To: Hermes-Lite <herme...@googlegroups.com>
Subject: Re: Companion board questions

 

--
You received this message because you are subscribed to a topic in the Google Groups "Hermes-Lite" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/hermes-lite/Z-OYbKdp-Pw/unsubscribe.
To unsubscribe from this group and all its topics, send an email to hermes-lite...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/hermes-lite/23b64522-b9d7-477c-b43f-003a02139cefn%40googlegroups.com.

[KP4RX - Ramon]

Hi Steve, while I'm not CW proficient, my coding skills are pretty raw, and also my pcb design skills are raw too, I would like to help moving forward with the project. I'm not a developer or electrical engineer (In fact I'm a Network Architect) but I do know how to manage software code and electronic circuits. I would just need a few pointers to the different firmwares and previous testing notes (If any). If you can send one of the keyers I can cover the shipping cost so the project's funds can be invested somewhere else. If we can find 9 or 10 testers willing to support it I can coordinate with makerfabs to build another small batch with the current design or including those updates you mentioned and work as a team to polish the Keyer for GA. Please let me know if you want to move forward on this.

73 de KP4RX

[Mike Lewis]

I have built this on just a Teensy 4.0 using MIDI for all control, integrated into one of my PiHPSDR controllers to act as an audio sound card feeding headphones and amplifier as well as a keyer and PTT buffering, no external hardware controls.  Every once in a while it hangs, but generally is pretty reliable, I have made no further changes to it I some time. 

 

I have leveraged the 48KHz changes from the keyer project in my own Teensy SDR project OpenAudio_Library (F32) + Teensy Audio library (I16) with success for full USB RX/TX audio at 48KHz.  I created a procedure to help modify the Teensy library with the necessary changes including creating a custom USB Type (Dual Serial+Audio) and making it show up correctly in Windows USB device properties.   This version I left out the clock correction code as that was another level of effort I was not ready to tackle. 

 

The above procedure was necessary because each version of TeensyDuino installs a new audio library requiring you apply the same changes each upgrade.  As the audio library changes each time, someone has to manually update a version and distribute it or a patch procedure/script.  To see longevity for this product in the hands of everyday users, a small team would have to update the library periodically to keep up with Arduino/TeensyDuino changes over time.   It is possible to compile with an old version but again, that requires more detailed user skills/instructions to manage multiple versions, especially multiple versions of TeensyDuino on the same computer.  AS far as I can tell, the uptake among my SDR code users has been very small, I think it is intimidating to all but experienced coders.

 

Paul and team were working with Arduino authors to better enable dynamic USB type detection  for Teensy.  I Have not looked at the most recent TeensyDuino/Arduino combo.  The USB types were hard coded into the Teensy discovery tools.  I manually updated the Arduino IDE boards.txt files to force my new USB type into the Tools USB Type menu, but it will not show up in the more easily seen pulldown menu listing the USB resources found.  Given the frequent updates to TeensyDuino and Arduino, I often skip the USB manual updates due to the amount of work it takes each time.

 

All of this to issue a warning.  The hardware part is easy to get right and produce.  You will face a more difficult task maintaining the software side as it requires specialized knowledge to commit to periodic updates over a long period of time to be considered proper support.  Supporting those changes in the wild could be time consuming also, TBD.  I suspect each of the keyer software authors know how to do this but will they want to commit to the long term effort surely to be required?

 

• Mike
• K7MDL

 

From: herme...@googlegroups.com <herme...@googlegroups.com> On Behalf Of KP4RX - Ramon
Sent: Monday, August 7, 2023 9:57 AM
To: Hermes-Lite <herme...@googlegroups.com>
Subject: Re: Companion board questions

 

Hi Steve, while I'm not CW proficient, my coding skills are pretty raw, and also my pcb design skills are raw too, I would like to help moving forward with the project. I'm not a developer or electrical engineer (In fact I'm a Network Architect) but I do know how to manage software code and electronic circuits. I would just need a few pointers to the different firmwares and previous testing notes (If any). If you can send one of the keyers I can cover the shipping cost so the project's funds can be invested somewhere else. If we can find 9 or 10 testers willing to support it I can coordinate with makerfabs to build another small batch with the current design or including those updates you mentioned and work as a team to polish the Keyer for GA. Please let me know if you want to move forward on this.

 

73 de KP4RX

Max

 

On Friday, 4 August 2023 at 22:42:17 UTC+1 radi...@mail.com wrote:

Just to clarify, the idea of this interface is not just a keyer. If you simply wish to work CW with the HL2 local to your operating position you can use regular keyer with (if software does not cater) local sidetone.

 

CW with SDRs sounds very simple but it's anything but. The simplest mode for most conventional analogue transceivers becomes the most tricky when it comes to SDRs! Yes, a few ms (granted quite a lot more than 2 or 3 ms can be tolerated) can be very off-putting especially when keying at higher speeds (25 wpm +). Anyway, there is latency inherent in any SDR, so it's impractical to do what many would do with an analogue rig and simply open up the RX front end slightly to listen to the actual (attenuated) TX signal. Instead you must rely on sidetone, either locally generated or in the software. Your mention of guitar via amp simulator is akin to the software providing the sidetone. SDR Console does this with latency adequate for up to perhaps about 30wpm. SparkSDR also provides sidetone. I do not know what the speed limitation is (if any). By far the easiest way around all of this is a keyer generated sidetone but then you slightly miss the luxury of perfectly netting the TX tone frequency on to the received station as you can with SDR Console for example. But that's no real issue I guess. In my experience of CW operators syncing tone frequency, relatively few people manage it!

 

Anyway, all of this is missing the point somewhat with ref to Steve's remote keyer. The whole point of HL2 is it is a networked radio. So all operations should be achievable over the network, be it your local LAN or a far away remote location. So idea of Steve's "Teensy Keyer" project is to be able to key the HL2 when it's located remotely at some distance away, while not worrying about latency of sidetone etc., so keys the TX over network, not via the front panel key jack that we might normally use for local operation. Not only that, but also serves as a standalone audio interface to which you can attach mic and speakers/headphones, so it makes the HL2 a complete "remote package" so to speak with no use of the PC soundcard.

 

All details here:

https://github.com/softerhardware/CWKeyer

 

Hope that helps to clarify what this interface does and achieves over and above a regular keyer like Winkeyer etc.

 

73

 

Max

 

 

On Friday, 4 August 2023 at 20:50:01 UTC+1 ron.le...@gmail.com wrote:

I have electric guitar that I plug into USB audio interface and use Guitarix to simulate tubes,  effects and Impulse Response cabinet emulation.  It does all this with no perceivable latency.  I'm not sure why CW can't be done in software SDR with at least that low of latency.  Does a couple ms latency really throw one off on CW?

On Friday, August 4, 2023 at 8:40:46 AM UTC-6 ya...@yarda.eu wrote:

It would be great if somebody experienced with Makerfabs and the
logistic stuff could organize group buy (without additional support). In
such case I would be interested in at least one keyer

73! Jaroslav, OK2JRQ

--

You received this message because you are subscribed to the Google Groups "Hermes-Lite" group.

To unsubscribe from this group and stop receiving emails from it, send an email to hermes-lite...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/hermes-lite/e4caac19-0de3-44cf-8ff6-01df4a4d0d05n%40googlegroups.com.

[Mike Lewis]

I should add, the below described library challenge would be moot if and when TeensyDuino picks up support for 48KHz or user selectable rates, something many folks have been looking for.  Maybe the default 44.1KHz can work instead of 48KHz (leveraging PC side resampling or SDR app config options).  There are also some changes addressing latency that may never make it into the main audio library. 

 

Hate to be a killjoy, as a current user I find this keyer design perfect for me, but one has to consider the software challenges ahead in parallel to the hardware side.  One thought I had was to use a dedicated low-cost USB audio chip fixed at 48KHz and do the rest in Arduino, removing the most troublesome portion of the project. Not as elegant but the software can focus on user features.

To view this discussion on the web visit https://groups.google.com/d/msgid/hermes-lite/MW4PR10MB5728FE929D50DE51D10D1548F60CA%40MW4PR10MB5728.namprd10.prod.outlook.com.

[Mike Lewis]

Changed the title to specify the keyer, not the companion board that was the original subject.

 

I did a quick look around and one of the first examples I came across of a USB Audio bridge is the CP2615 from Silicon Labs.  Has I2S interface and requires no drivers, minimal software interface.  16bit at 48KHz. 

CP2615 USB Audio Bridge - Silicon Labs (silabs.com)

To view this discussion on the web visit https://groups.google.com/d/msgid/hermes-lite/MW4PR10MB57284F4A764B92A5FF13F961F60CA%40MW4PR10MB5728.namprd10.prod.outlook.com.

[Mike Lewis]

The CP2615 and related family chips appear to be destined for the obsolete pile.   I was not able to find any replacement function USB/I2S chips that were going to be around for a while.  Some options did not support 48K or even 44.1K.  Maybe a SPDIF to USB interface.  So much for the easy(ier) hardware answer….   I was reading a 2020-2021 thread that suggest professional audio products are or have moved to ethernet.  Perhaps the low cost audio products are now using codecs with integrated USB.

[Steve Haynal]

Hi Ramon,

Sounds good. Please send me a private message with your shipping address. I'll cover the shipping costs from the R&D pool. If it doesn't work out for you, you can forward it on to someone else. Thanks for volunteering!

73,

Steve

kf7o

[Steve Haynal]

Hi Mike,

The original plan to deal with this problem was to distribute a compiled binary updates, and then users would only use a utility to program the CW keyer. No need for an average user to install the customer library, just developers. There was a utility to do this about a year ago. Do you know if it is still available?

73,

Steve

kf7o

[Mike Lewis]

You can use TeensyLoader (or TyCommander, my favorite) to upload hex files.  We do this for some novice SDR builders.

To view this discussion on the web visit https://groups.google.com/d/msgid/hermes-lite/e6cc1c2c-d85c-453a-8b99-bd6d850e899fn%40googlegroups.com.

[Steve Haynal]

Hi Group,

Some people on the facebook group wanted more discussion and answers on this topic, so I made a post which I cross post below. There has been an amazing number of new users recently, and consequently there are many questions out there.

73,

Steve

kf7o

Steve Haynal

Hi Group,

Thanks for asking for my input. I'd like to share some thoughts regarding how to achieve the best user experience with a stock HL2, commodity soundcards, and more software-oriented solutions. Please post any questions or additional ideas. Sometimes it can be difficult to setup software, or the software is not yet complete, but I am a proponent of more software and less custom hardware for software defined radio whenever possible. I believe that is the future of SDR, especially for low cost SDR.

One concern that comes up frequently is audio latencies. Let us consider two types of audio latency: microphone-to-antenna and microphone-to-headphones. The path for microphone-to-antenna with an external sound card is:

1. microphone

2. soundcard to host

3. vac and resampling

4. software processing to convert LR audio into IQ samples for HL2

5. network transport to HL2

6. HL2 buffering and processing

7. antenna

The similar path for a hardware codec chip in the HL2 is:

1. microphone

2. HL2 buffering and processing

3. network transport to host computer

4. software processing to convert LR audio into IQ samples for HL2

5. network transport to HL2

6. HL2 buffering and processing

7. antenna

Both of these paths will take tens of milliseconds to complete and have roughly the same latency. There is no significant latency reduction expected for a hardware codec chip in the HL2 here. This can be measured by applying an audio signal to the microphone and measuring the time until an RF signal appears on the antenna output.

When you consider that it takes a radio wave ~130ms to complete one circle around the earth, microphone-to-antenna latency of tens of milliseconds doesn't matter much for the user experience. If you aren't listening to yourself on a speaker when you talk (the way I'd like to operate, like a Zoom or Teams meeting), then this latency is not an issue.

Some operators like to hear themselves in headphones while they talk with near-zero latency. If that is what you want, then a hardware codec chip should be able to route microphone samples directly to the headphones and bypass any software. You can also find relatively inexpensive audio interfaces with direct monitoring capabilities which do the same thing:

https://www.amazon.com/BEHRINGER-Audio.../dp/B00EK1OTZC...

(I haven't used this interface. It is an example. There are many inexpensive commodity USB audio interfaces.)

If you only want to monitor your microphone during TX, software may need to be updated to turn direct monitoring on or off, perhaps via a midi command.

Sometimes users try and setup up this type of monitoring with VAC and through the SDR software. That can be complex and subject to latencies. You should have a much better experience with direct monitoring. Avoid VAC when self monitoring, but the latency of VAC doesn't matter for signals going to the antenna.

The audio interface in the prototype CW keyer can also do this near zero latency direct monitoring. The CW keyer with audio interface is more than a K3NG keyer with audio output. It is a USB audio device with both audio in and out. It shows up as a USB 2.0 audio device when the USB is plugged into the computer. It combines an audio interface with a keyer so that near zero CW sidetone can be mixed with audio from the HL2.

The advantage of using an external sound card or the separate CW keyer with audio interface is that you can operate with the HL2 right by you or remotely and everything remains the same. Also, if you buy a nicer sound card, you can use the flexibility and functionality it offers for other purposes.

[Rick Langford (N8SDR)]

Great info Steve.

I think that  needed to be mentioned so users  (esp some of use new ones) can make an informed buying decision! Before spending extras on possibly unneeded hardware that in situations may or may not really be required.

Rick

Get Outlook for Android

---

From: herme...@googlegroups.com <herme...@googlegroups.com> on behalf of Steve Haynal <softerh...@gmail.com>

Sent: Tuesday, August 8, 2023 12:39:53 AM

You received this message because you are subscribed to a topic in the Google Groups "Hermes-Lite" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/hermes-lite/Z-OYbKdp-Pw/unsubscribe.
To unsubscribe from this group and all its topics, send an email to hermes-lite...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/hermes-lite/2ebbddd2-cde7-4d7b-9eba-ba17b03ae784n%40googlegroups.com.

[radi...@mail.com]

My main interest in the Teensy keyer is to be able to send CW with the HL2 remote from the operating position, ideally with SDR Console. Can I please ask, has anyone who built the Teensy Keyer use it for CW with SDR Console? If so, how is this achieved? I think it means assigning a MIDI note to CW keying in the software (I would guess)? So maybe this means asking Simon to add a midi command to key the TX in CW mode, which as far as I can see it does not at the moment? Apologies if I misunderstand how it works at a basic level.

Sorry to report I am one of the half-wits that cannot program to save my life. Perfectly capable of following a set of clear step-by-step instructions, but not write/modify any but the most basic code.  

73

Max

On Tuesday, 8 August 2023 at 12:13:44 UTC+1 service...@gmail.com wrote:

Great info Steve.

I think that  needed to be mentioned so users  (esp some of use new ones) can make an informed buying decision! Before spending extras on possibly unneeded hardware that in situations may or may not really be required.

Rick

Get Outlook for Androidle.com/d/msgid/hermes-lite/2ebbddd2-cde7-4d7b-9eba-ba17b03ae784n%40googlegroups.com.

[James K4JK]

Hi Steve et. al.

I'd like to help with the Teensy project, since I still do quite a bit of CW operating. 

About me: I'm currently a domain architect,  so I don't code much anymore professionally but hopefully I haven't forgotten how. :-) Happy to also help with testing etc.

I wrote some of the community software for the Ten Tec 506 (Rebel) so this wouldn't be my first rodeo in open source QRP.

Please let me know how I can help. Thanks!

73

K4JK

[Ron Lewkowicz]

The monitoring latency issues would probably have been a non-issue had SDR developers added Jack Audio support.  It's fully cross platform and can provide ultra low latency audio and network audio.  I've been using this in Linux for decades.  All my USB audio interfaces have a direct monitor feature. Some can mix the direct with the USB audio.  I've never needed to use this.

Pipewire is something new in Linux which essentially merges Pulse audio and Jack audio. As a result existing SDR applications have better latency performance and better audio routing without any changes to the SDR application.   I find no issue monitoring microphone audio in headphones with this.

[Steve Haynal]

Hi Max,

I think Simon has one of these keyers. You do use midi with it to send CW remotely.

73,

Steve

kf7o

[Steve Haynal]

Hi James,

Let me see if I can find one to send you. Please send me a private message with your shipping address.

73,

Steve

kf7o

[Steve Haynal]

Hi Ron,

I also enjoy using Linux with Jack Audio. Pipewire is on my list to try. I think you are probably a more advanced user. It seems like people have more problems than not configuring low latency audio, especially on Windows when they have to use VAC with Thetis. Direct monitoring if available on the sound card may be easier for some.

73,

Steve

kf7o

[radi...@mail.com]

Thank you Simon for the response. AFAIK there is not currently a midi command in Simon's instruction set for SDRC to key down in CW mode but I will ask him about it.

73

Max