开云体育

  1. Direwolf
  2. Topics

Changing from Signalink to Easy Digi

 

Hello all. My APRS station is a Pi 3B, Signalink, and Kenwood TM-281a running Direwolf and YAAC. Runs great. I replaced the Signalink with an Easy Digi and a Sabrent USB adapter. I cannot get the system to transmit. Is there a change I need to make in direwolf.conf? I tried making changes in the lines below with no success. Thanks for your help.?

#PTT COM1 RTS
#PTT COM1 RTS -DTR
#PTT /dev/ttyUSB0 RTS
 

Hello Fred,

Assuming you added a USB sound adapter and a USB to serial adapter, the PTT line should look like this:

PTT /dev/ttyUSB0 RTS DTR

If that doesn't work, try this:

PTT /dev/ttyUSB0 DTR RTS

I don't recall exactly which one of the two worked for me when I was using an EasyDigi board.


73,
Lee K5DAT


On Sun, Nov 20, 2022 at 5:30 PM Fred Bouwman <bouwmanf@...> wrote:
Hello all. My APRS station is a Pi 3B, Signalink, and Kenwood TM-281a running Direwolf and YAAC. Runs great. I replaced the Signalink with an Easy Digi and a Sabrent USB adapter. I cannot get the system to transmit. Is there a change I need to make in direwolf.conf? I tried making changes in the lines below with no success. Thanks for your help.?

#PTT COM1 RTS
#PTT COM1 RTS -DTR
#PTT /dev/ttyUSB0 RTS
 

开云体育


Hello Fred,

When you say a Sabrent USB adapter, do you mean a Sabrent sound device?? If so, that device will only support *sound* out of the box.? Depending on your specific sound device, some can be opened up and you can add a PTT circuit to it if you're willing to try:

??


If you don't want to do that, you can use a GPIO pin off your Raspberry Pi itself and with a simple transistor circuit, you can use that:

??

--David
KI6ZHD


On 11/20/2022 03:30 PM, Fred Bouwman wrote:

Hello all. My APRS station is a Pi 3B, Signalink, and Kenwood TM-281a running Direwolf and YAAC. Runs great. I replaced the Signalink with an Easy Digi and a Sabrent USB adapter. I cannot get the system to transmit. Is there a change I need to make in direwolf.conf? I tried making changes in the lines below with no success. Thanks for your help.?

#PTT COM1 RTS
#PTT COM1 RTS -DTR
#PTT /dev/ttyUSB0 RTS
 

Hi Fred,

The first thing to check is that you wired the connections from the Easy Digi interface and the Kenwood radio properly. In particular it is important that both the Mic Gnd and the PTT Gnd connections from the Easy Digi are connected to the radio ground.

The Easy Digi implements a Vox interface for PTT. In order for this circuit to work, there has to be sufficient output volume on the Sabrent USB sound fob/dongle. Try turning up the speaker volume for the USB sound interface to see if this helps to generate PTT.

No PTT configuration is needed in direwolf.conf when using Vox, so these commented out PTT lines are fine.

73,
Thomas
KK6FPP
 

开云体育


The Easy Digi isolation boards that I'm aware of do NOT support any form of PTT control.? To function, they get wired up something like this:

??


Please note... the use of VOX is NOT recommended for Packet Radio.? Please read section 9.2.13.1 of the Direwolf User Guide:

??


--David
KI6ZHD



On 11/20/2022 04:00 PM, Thomas Leibold wrote:

Hi Fred,

The first thing to check is that you wired the connections from the Easy Digi interface and the Kenwood radio properly. In particular it is important that both the Mic Gnd and the PTT Gnd connections from the Easy Digi are connected to the radio ground.

The Easy Digi implements a Vox interface for PTT. In order for this circuit to work, there has to be sufficient output volume on the Sabrent USB sound fob/dongle. Try turning up the speaker volume for the USB sound interface to see if this helps to generate PTT.

No PTT configuration is needed in direwolf.conf when using Vox, so these commented out PTT lines are fine.

73,
Thomas
KK6FPP

 

Hi,

David is correct. I was actually looking at the same page he linked to but was mislead by the comments about Vox in the text on that page. I missed the GPIO signal from the Raspberry Pi going to the Easy Digi board, mistaking the red and blue lines as power supply.

This also means that there is a need for a PTT line in the direwolf.conf file. If you followed the example on the openrepeater.com website and used Pin 12 (GPIO 18) on the Raspberry Pi then the corresponding entry in the direwolf.conf file would be PTT GPIO 18.

As for Vox not being recommended that is without question. However there is a difference between the Vox feature inside many radios (which is intended for Voice communication only) and a fast-acting Vox circuit inside a computer-radio interface (such as Signalink and some DRA models which can indeed be used for digital communication).

A real PTT signal under software control will always be superior to a Vox circuit.

73,
Thomas
KK6FPP
 

Hi,

This thread caught me eye as I have two SignaLinks (along with cables and modules for Yaesu 8900, Alinco DR-235, Baofengs/Kenwood/etc, Anyone 778UV, etc) and usd to use one for APRS/digipeater/igate stuff, but now using just one of the EasyDigi’s. Have three EasyDigi’s, the two shown here and one in current use with s FT60R going into an amplifier and out a jpole (that one also has the blue USB PTT cable). I’m using just a RPi02W for DireWolf and triggering the USB by “PTT /dev/ttyUSB0 RTS DTR” in direwolf.conf. For audio, I’m using a “Fe-Pi” audio hat (well, actually it is WB7FHC’s clone since the Fe-Pi is no longer made), and it works great. Google “Nexus DR-X” and then look at part listing if anyone is interested in getting one of those boards. I have two and they work a treat. They don’t get disconnected by RF like sometimes the USB sound dongles do.

The EasyDigi on the left is just a VOX one. I don’t really care to use just VOX, but sometimes it is convenient, especially with just a cheap Baofeng or such. I have a few of the BTech K1-APRS cables, but found the EasyDigi to work much better. Also have a MobiLinkD TNC3 that is part of my WinLink Gateway. That’s a great device too, but currently on hold due to world chip shortage. Hoping the MobiLink is sold again soon as been patiently waiting to get a second one.

Anyway, just saw the post about switching from using a SignaLink to EasyDigi and thought I’d chime in as I did the same. When I was using the SignaLink, it was able to trigger PTT on my mobile and didn’t have to use VOX.

EasyDigi’s are great devices to have also though.

Cheers,
Jerry




Sent from my iPhone 13 Pro Max

On Nov 20, 2022, at 8:29 PM, Thomas Leibold <leibold@...> wrote:

?Hi,

David is correct. I was actually looking at the same page he linked to but was mislead by the comments about Vox in the text on that page. I missed the GPIO signal from the Raspberry Pi going to the Easy Digi board, mistaking the red and blue lines as power supply.

This also means that there is a need for a PTT line in the direwolf.conf file. If you followed the example on the openrepeater.com website and used Pin 12 (GPIO 18) on the Raspberry Pi then the corresponding entry in the direwolf.conf file would be PTT GPIO 18.

As for Vox not being recommended that is without question. However there is a difference between the Vox feature inside many radios (which is intended for Voice communication only) and a fast-acting Vox circuit inside a computer-radio interface (such as Signalink and some DRA models which can indeed be used for digital communication).

A real PTT signal under software control will always be superior to a Vox circuit.

73,
Thomas
KK6FPP




image0.jpeg

 

Hey All,

Here is a pic of the “interface” I build that utilizes the Easy-Digi with a “Soundcard” that allows full PTT between the rig if my choosing and a Pi3,4 or whatever.

The 3D printed box I/O’s are phono jacks that allow me to make whatever interface cable I need between the rig of my choosing (Kenwood,Yaesu, etc) and the “box”…then the box plugs into the Pi via a micro usb / usb cable. I run Direwolf and Xastir on the Pi’s for APRS solely. Hope this helps..
73,
Danny NF4J

Sent using the mobile mail app

On 11/20/22 at 19:29, Thomas Leibold wrote:

Hi,

David is correct. I was actually looking at the same page he linked to but was mislead by the comments about Vox in the text on that page. I missed the GPIO signal from the Raspberry Pi going to the Easy Digi board, mistaking the red and blue lines as power supply.

This also means that there is a need for a PTT line in the direwolf.conf file. If you followed the example on the openrepeater.com website and used Pin 12 (GPIO 18) on the Raspberry Pi then the corresponding entry in the direwolf.conf file would be PTT GPIO 18.

As for Vox not being recommended that is without question. However there is a difference between the Vox feature inside many radios (which is intended for Voice communication only) and a fast-acting Vox circuit inside a computer-radio interface (such as Signalink and some DRA models which can indeed be used for digital communication).

A real PTT signal under software control will always be superior to a Vox circuit.

73,
Thomas
KK6FPP





IMG_2261.png

 

开云体育

Hi.

I actually just received a third “Fe-Pi” clone since u like these so much. ?Unlike USB dongles that sometimes need ferrit chokes to keep from being knocked out by RF, these are immune since they use the GPIO pins. ?I still need to solder a GPIO header onto this new one (they are sold without headers to keep price down). ?If you don’t like to solder, you could also just use hammer headers, but be very careful not to damage the capacitors. ?(It’s better to just solder than taje s chance). ?These are awesome boards that are Plug n’ Play with RPi’s. ?You’d think there would be more audio boards out there with a simple RPi0 form factor, but oddly the only really thing out there are the “Audio injectors”, which likely would be too also, but the “Fe-Pi” is much nicer.

I just shown the “KEPULU” sound dongles on the left because they are currently incredibly cheap on Amazon (I bought them for only $1.89/each, lol), however they do seem to work just fine for quick and dirty stuff or when you just need an extra sound dongle for something. ?I wouldn’t use them for RF stuff though, like a TNC, as the RF is likely to knock them out unless they are adequately shielded ot choked.

The “Fe-Pi” boards can be purchased at the following website. ?I’m not affiliated with him or anything, I just think he sells an online absolutely excellent product.


image0.jpeg

13 Pro Max

On Nov 21, 2022, at 8:00 AM, J K via groups.io <kuhnje@...> wrote:

?Hi,

This thread caught me eye as I have two SignaLinks (along with cables and modules for Yaesu 8900, Alinco DR-235, Baofengs/Kenwood/etc, Anyone 778UV, etc) and usd to use one for APRS/digipeater/igate stuff, but now using just one of the EasyDigi’s. ?Have three EasyDigi’s, the two shown here and one in current use with s FT60R going into an amplifier and out a jpole (that one also has the blue USB PTT cable). ?I’m using just a RPi02W for DireWolf and triggering the USB by “PTT /dev/ttyUSB0 RTS DTR” in direwolf.conf. ?For audio, I’m using a “Fe-Pi” audio hat (well, actually it is WB7FHC’s clone since the Fe-Pi is no longer made), and it works great. ?Google “Nexus DR-X” and then look at part listing if anyone is interested in getting one of those boards. ?I have two and they work a treat. ?They don’t get disconnected by RF like sometimes the USB sound dongles do.

The EasyDigi on the left is just a VOX one. ?I don’t really care to use just VOX, but sometimes it is convenient, especially with just a cheap Baofeng or such. ?I have a few of the BTech K1-APRS cables, but found the EasyDigi to work much better. Also have a MobiLinkD TNC3 that is part of my WinLink Gateway. That’s a great device too, but currently on hold due to world chip shortage. ?Hoping the MobiLink is sold again soon as been patiently waiting to get a second one. ?

Anyway, just saw the post about switching from using a SignaLink to EasyDigi and thought I’d chime in as I did the same. When I was using the SignaLink, it was able to trigger PTT on my mobile and didn’t have to use VOX. ?

EasyDigi’s are great devices to have also though.

Cheers,
Jerry




13 Pro Max

On Nov 20, 2022, at 8:29 PM, Thomas Leibold <leibold@...> wrote:

?Hi,

David is correct. I was actually looking at the same page he linked to but was mislead by the comments about Vox in the text on that page. I missed the GPIO signal from the Raspberry Pi going to the Easy Digi board, mistaking the red and blue lines as power supply.

This also means that there is a need for a PTT line in the direwolf.conf file. If you followed the example on the openrepeater.com website and used Pin 12 (GPIO 18) on the Raspberry Pi then the corresponding entry in the direwolf.conf file would be PTT GPIO 18.

As for Vox not being recommended that is without question. However there is a difference between the Vox feature inside many radios (which is intended for Voice communication only) and a fast-acting Vox circuit inside a computer-radio interface (such as Signalink and some DRA models which can indeed be used for digital communication).

A real PTT signal under software control will always be superior to a Vox circuit.

73,
Thomas
KK6FPP










<image0.jpeg>

 

Hey All,

Here are some better pics of the Interface I build at home. Craig - KO5S, builds the 3D boxes and I do the rest...but it was all his idea from a post he read a while back. Hope they help someone...

73,
Danny? - NF4J

AP1.jpg
AP2.jpg
AP3.jpg
AP5.jpg

 

David this is the device I am using with the Easy Digi.

https://www.amazon.com/gp/product/B00IRVQ0F8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

 

On Sun, Nov 20, 2022 at 03:30 PM, Fred Bouwman wrote:
Kenwood TM-281a r
I do not recommend the easy-digi interface.?
Isolation transformers are rarely necessary unless connecting to old vacuum tube transceivers.?
The high frequency rolloff of the isolation transformers will prevent the faster data rates.?
?
The CM108 chip on the Sabrent sound dongle is likely covered with epoxy?
and will be hard to attach a wire to pin 13 on the USB sound dongle.? ?
I used a bare CM108 USB sound dongle. Only $4.?
https://www.ebay.com/itm/203958052588?
Instructions to modify for PTT control:?
https://allstarsetup.com/how-to-modify-a-cm108-sound-fob-for-allstar/?
Skip the connection for COS, it is only necessary for the AllStar application.?
Instead of the 10k axial resistor, I reused one of the SMD microphone bias resistors removed from R6 and R7 on the dongle.
If you have no soldering skill, you can buy an assembled unit.?
https://hamprojects.info/dinah/ or?
?
fldigi, direWolf, soundmodem, ARDOP and VARA Winlink have added direct?
CM108/CM119 PTT support in their Linux and Windows versions.?
For other digital modes like WSJTx (FT8) and JS8Call use CAT7200?
to emulate the RTS interface for PTT.?
http://www.cantab.net/users/john.wiseman/Documents/CAT7200.html?
?
In direwolf.conf, comment out the other PTT methods and use?
"PTT CM108"?
See page 6 of the TM281A manual for connection info.?
https://kasc.kenwood.com/files/prod/2422/5/TM-281A_E_Instruction_Manual_V2_B62-2347-20.pdf?
?
If you suffer from common-mode "RF in the shack",?
I additionally recommend using a shielded USB extension cable, and
soldering 100pF capacitors from GND to MIC, SPKR and PTT on the dongle.?

 

The CM108 Sound FOB is the same card I use with my easy-digi builds, BUT, my?configuration is completely different....as referenced in the pics I attached earlier.
?
73,
Danny? NF4J

?
?
Sent:?Monday, November 21, 2022 at 10:52 AM
From:?"N0YWB" <n0ywb1@...>
To:[email protected]
Subject:?Re: [direwolf] Changing from Signalink to Easy Digi
On Sun, Nov 20, 2022 at 03:30 PM, Fred Bouwman wrote:
Kenwood TM-281a r
I do not recommend the easy-digi interface.?
Isolation transformers are rarely necessary unless connecting to old vacuum tube transceivers.?
The high frequency rolloff of the isolation transformers will prevent the faster data rates.?
?
The CM108 chip on the Sabrent sound dongle is likely covered with epoxy?
and will be hard to attach a wire to pin 13 on the USB sound dongle.? ?
I used a bare CM108 USB sound dongle. Only $4.?
?
Instructions to modify for PTT control:?
?
Skip the connection for COS, it is only necessary for the AllStar application.?
Instead of the 10k axial resistor, I reused one of the SMD microphone bias resistors removed from R6 and R7 on the dongle.
If you have no soldering skill, you can buy an assembled unit.?
or?
?
fldigi, direWolf, soundmodem, ARDOP and VARA Winlink have added direct?
CM108/CM119 PTT support in their Linux and Windows versions.?
For other digital modes like WSJTx (FT8) and JS8Call use CAT7200?
to emulate the RTS interface for PTT.?
?
?
In direwolf.conf, comment out the other PTT methods and use?
"PTT CM108"?
See page 6 of the TM281A manual for connection info.?
?
?
If you suffer from common-mode "RF in the shack",?
I additionally recommend using a shielded USB extension cable, and
soldering 100pF capacitors from GND to MIC, SPKR and PTT on the dongle.?
?

 

Here's the Config for how mine is setup... See attached.
?
73,
Danny? NF4J

?
?
Sent:?Monday, November 21, 2022 at 11:14 AM
From:?"Danny Bush" <NF4J@...>
To:[email protected]
Subject:?Re: [direwolf] Changing from Signalink to Easy Digi
The CM108 Sound FOB is the same card I use with my easy-digi builds, BUT, my?configuration is completely different....as referenced in the pics I attached earlier.
?
73,
Danny? NF4J
?
?
Sent:?Monday, November 21, 2022 at 10:52 AM
From:?"N0YWB" <n0ywb1@...>
To:[email protected]
Subject:?Re: [direwolf] Changing from Signalink to Easy Digi
On Sun, Nov 20, 2022 at 03:30 PM, Fred Bouwman wrote:
Kenwood TM-281a r
I do not recommend the easy-digi interface.?
Isolation transformers are rarely necessary unless connecting to old vacuum tube transceivers.?
The high frequency rolloff of the isolation transformers will prevent the faster data rates.?
?
The CM108 chip on the Sabrent sound dongle is likely covered with epoxy?
and will be hard to attach a wire to pin 13 on the USB sound dongle.? ?
I used a bare CM108 USB sound dongle. Only $4.?
?
Instructions to modify for PTT control:?
?
Skip the connection for COS, it is only necessary for the AllStar application.?
Instead of the 10k axial resistor, I reused one of the SMD microphone bias resistors removed from R6 and R7 on the dongle.
If you have no soldering skill, you can buy an assembled unit.?
or?
?
fldigi, direWolf, soundmodem, ARDOP and VARA Winlink have added direct?
CM108/CM119 PTT support in their Linux and Windows versions.?
For other digital modes like WSJTx (FT8) and JS8Call use CAT7200?
to emulate the RTS interface for PTT.?
?
?
In direwolf.conf, comment out the other PTT methods and use?
"PTT CM108"?
See page 6 of the TM281A manual for connection info.?
?
?
If you suffer from common-mode "RF in the shack",?
I additionally recommend using a shielded USB extension cable, and
soldering 100pF capacitors from GND to MIC, SPKR and PTT on the dongle.?
?

USB_FOB_nobias_enhanced2.jpeg

 

Great info, but I don't agree with "If you have no soldering skill".? I have soldered lots of things including some very small wires on a microphone replacement cable that was part of a custom cable used to provide an external packet port on a radio that did not have one built in.? I find soldering a PTT wire on that CM108 dongle (to the corner pin on the chip) to be fairly difficult, and internet searches show I'm not the only one.

73,
Lee K5DAT


On Mon, Nov 21, 2022 at 10:52 AM N0YWB <n0ywb1@...> wrote:
On Sun, Nov 20, 2022 at 03:30 PM, Fred Bouwman wrote:
Kenwood TM-281a r
I do not recommend the easy-digi interface.?
Isolation transformers are rarely necessary unless connecting to old vacuum tube transceivers.?
The high frequency rolloff of the isolation transformers will prevent the faster data rates.?
?
The CM108 chip on the Sabrent sound dongle is likely covered with epoxy?
and will be hard to attach a wire to pin 13 on the USB sound dongle.? ?
I used a bare CM108 USB sound dongle. Only $4.?
?
Instructions to modify for PTT control:?
?
Skip the connection for COS, it is only necessary for the AllStar application.?
Instead of the 10k axial resistor, I reused one of the SMD microphone bias resistors removed from R6 and R7 on the dongle.
If you have no soldering skill, you can buy an assembled unit.?
or?
?
fldigi, direWolf, soundmodem, ARDOP and VARA Winlink have added direct?
CM108/CM119 PTT support in their Linux and Windows versions.?
For other digital modes like WSJTx (FT8) and JS8Call use CAT7200?
to emulate the RTS interface for PTT.?
?
?
In direwolf.conf, comment out the other PTT methods and use?
"PTT CM108"?
See page 6 of the TM281A manual for connection info.?
?
?
If you suffer from common-mode "RF in the shack",?
I additionally recommend using a shielded USB extension cable, and
soldering 100pF capacitors from GND to MIC, SPKR and PTT on the dongle.?

 

Lee,
?
Using the right 30ga wire is the key to making that connection. I use a pretty larger magnifier to assist my aging eyes!! HIHI!
?
Danny? NF4J

?
?
Sent:?Monday, November 21, 2022 at 11:19 AM
From:?"Lee Bengston" <kilo5dat@...>
To:[email protected]
Subject:?Re: [direwolf] Changing from Signalink to Easy Digi
Great info, but I don't agree with "If you have no soldering skill".? I have soldered lots of things including some very small wires on a microphone replacement cable that was part of a custom cable used to provide an external packet port on a radio that did not have one built in.? I find soldering a PTT wire on that CM108 dongle (to the corner pin on the chip) to be fairly difficult, and internet searches show I'm not the only one.
?
73,
Lee K5DAT
?
?
On Mon, Nov 21, 2022 at 10:52 AM N0YWB <n0ywb1@...> wrote:
On Sun, Nov 20, 2022 at 03:30 PM, Fred Bouwman wrote:
Kenwood TM-281a r
I do not recommend the easy-digi interface.?
Isolation transformers are rarely necessary unless connecting to old vacuum tube transceivers.?
The high frequency rolloff of the isolation transformers will prevent the faster data rates.?
?
The CM108 chip on the Sabrent sound dongle is likely covered with epoxy?
and will be hard to attach a wire to pin 13 on the USB sound dongle.? ?
I used a bare CM108 USB sound dongle. Only $4.?
?
Instructions to modify for PTT control:?
?
Skip the connection for COS, it is only necessary for the AllStar application.?
Instead of the 10k axial resistor, I reused one of the SMD microphone bias resistors removed from R6 and R7 on the dongle.
If you have no soldering skill, you can buy an assembled unit.?
or?
?
fldigi, direWolf, soundmodem, ARDOP and VARA Winlink have added direct?
CM108/CM119 PTT support in their Linux and Windows versions.?
For other digital modes like WSJTx (FT8) and JS8Call use CAT7200?
to emulate the RTS interface for PTT.?
?
?
In direwolf.conf, comment out the other PTT methods and use?
"PTT CM108"?
See page 6 of the TM281A manual for connection info.?
?
?
If you suffer from common-mode "RF in the shack",?
I additionally recommend using a shielded USB extension cable, and
soldering 100pF capacitors from GND to MIC, SPKR and PTT on the dongle.?
?

?

?

 

开云体育

Hi,

Hui definitely aren’t the only one to find soldering those thin gauge wires to be a MAJOR PITA. ?I’ve done quite a bit of even SMC repair in the military, but find wiring with the hose dongles (I’ve made a couple URI’s for AllStar nodes) to be a PITA, even on my clean, well lit, workbench, and I use a USB microscope even. ?Of course, it doesn’t help that my eyesight is going (getting older sucks) and have moderate neuropathy going down entire right side (including dominant right hand) from a TBI I had.

13 Pro Max

On Nov 21, 2022, at 12:19 PM, Lee Bengston <kilo5dat@...> wrote:

?
Great info, but I don't agree with "If you have no soldering skill".? I have soldered lots of things including some very small wires on a microphone replacement cable that was part of a custom cable used to provide an external packet port on a radio that did not have one built in.? I find soldering a PTT wire on that CM108 dongle (to the corner pin on the chip) to be fairly difficult, and internet searches show I'm not the only one.

73,
Lee K5DAT


On Mon, Nov 21, 2022 at 10:52 AM N0YWB <n0ywb1@...> wrote:
On Sun, Nov 20, 2022 at 03:30 PM, Fred Bouwman wrote:
Kenwood TM-281a r
I do not recommend the easy-digi interface.?
Isolation transformers are rarely necessary unless connecting to old vacuum tube transceivers.?
The high frequency rolloff of the isolation transformers will prevent the faster data rates.?
?
The CM108 chip on the Sabrent sound dongle is likely covered with epoxy?
and will be hard to attach a wire to pin 13 on the USB sound dongle.? ?
I used a bare CM108 USB sound dongle. Only $4.?
?
Instructions to modify for PTT control:?
?
Skip the connection for COS, it is only necessary for the AllStar application.?
Instead of the 10k axial resistor, I reused one of the SMD microphone bias resistors removed from R6 and R7 on the dongle.
If you have no soldering skill, you can buy an assembled unit.?
or?
?
fldigi, direWolf, soundmodem, ARDOP and VARA Winlink have added direct?
CM108/CM119 PTT support in their Linux and Windows versions.?
For other digital modes like WSJTx (FT8) and JS8Call use CAT7200?
to emulate the RTS interface for PTT.?
?
?
In direwolf.conf, comment out the other PTT methods and use?
"PTT CM108"?
See page 6 of the TM281A manual for connection info.?
?
?
If you suffer from common-mode "RF in the shack",?
I additionally recommend using a shielded USB extension cable, and
soldering 100pF capacitors from GND to MIC, SPKR and PTT on the dongle.?

<cm108_mod_for_TM281A.jpg>

 

On Mon, Nov 21, 2022 at 05:00 AM, J K wrote:
I added "PTT /dev/ttyUSB0 RTS DTR” and that resolved the will not transmit issue. Thank you. However, the signal it is transmitting is not the "squawck" sound of an APRS signal but a hum. I will start a new topic for that. Thank you all for your help it is greatly appreciated.?

 

开云体育

Hi,

You are using a USB dongle for audio?

So you have the proper:

“ADEVICE plughw:1,0” line?

Actually, the “1” will depend which USB port it’s recognized on.

From the CLI, do a “$ aplay -l” to see what port the speaker is on, followed by a “$ arecord -l” to see what port the mic is on. ?They will likely be on the same. ?Say if they are on 2, then add this to direwolf.conf

“ADEVICE plughw:2,0”

Don’t forget to save, kill any DireWolf processes running “$ killall direwolf” then restart using your .conf by “$ direwolf -c direwolf.conf”

13 Pro Max

On Nov 21, 2022, at 3:50 PM, Fred Bouwman <bouwmanf@...> wrote:

?On Mon, Nov 21, 2022 at 05:00 AM, J K wrote:
I added "PTT /dev/ttyUSB0 RTS DTR” and that resolved the will not transmit issue. Thank you. However, the signal it is transmitting is not the "squawck" sound of an APRS signal but a hum. I will start a new topic for that. Thank you all for your help it is greatly appreciated.?

 

Hi,

There are indeed some Sabrent USB Sound Fob/Dongles that have a C-Media chip where GPIO3 (pin 13) can be used for PTT. However the specific Sabrent model that Fred linked to at Amazon is using an HS100B chip (also from C-Media).

The cheaper HS100 chips, while partially compatible with the CM108, CM109 and CM119 chips, lack the GPIO pins for PTT output.

I tend to buy the cheaper dongles that come without case and that look like the one in Danny's pictures. The PCB is always the same (on the ones I got from different sellers) but there are subtle differences on the printing. The name in the top left corner has been most often "HW-349" (with variations like the crystal being labeled either Y1 or OSC) and "SW-HF07 V3.1" but I have also seen "NC". Some pcb prints are missing labels next to the larger capacitors. Common on all those boards is the number 160222 next to U1..

I'll try to attach a picture of two of those CM108 fobs/dongles where I added the wires for the GPIO3 modification (PTT output). Ideally R6 (next to the Mic connector) should be removed as well but is still present in the picture (it adds a 3.3V DC component to the audio input which is never needed when used as radio adapter and in rare cases can be harmful).

The first wire on the Mic connector sleve pin is ground. The second wire feeds the GPIO 3 (pin13 of the CM108/A/B) to the anode of a 3mm red signal LED. The cathode of the led is connected via 220 Ohm resistor to the base of a general purpose NPN transistor (2N2222, 2SC1213 or BC337 depending on whether you are in America, Asia or Europe). Emitter of the transistor is connected to Ground and Collector of the transistor is the PTT to the radio. The advantage of this simple circuit is that you get a PTT indicator LED without extra effort.

73,
Thomas
KK6FPP

CM108fobs_GPIO3mod.jpg
GPIO3_PTT.png

1 - 20 of 21