[amsat-bb] Falconsat Success

[Scott]

Glad to help, Tony.  I'll reply to the mailing list in case anyone else is 
interested.

First, your computer needs a port (usually serial) to trigger the relay.  My 
computer did not have one, so I bought a USB > Serial cable.

There are discussions online regarding that the different types of USB > 
Serial cables do or don't work for this purpose.  The following cable is 
working well for me:

https://smile.amazon.com/gp/product/B006AA04K0

(if you don't already have a charity linked to Amazon's "SMILE" program, now 
is a good opportunity to set that to AMSAT!)

As I mentioned earlier, to make it easier to access the serial pins you 
need, a breakout adapter is handy.  Others may wish to solder a permanent 
connection, but I use the following:

https://smile.amazon.com/gp/product/B00WW6P636

... and to save people having to scroll through previous posts, here is the 
relay itself:

https://smile.amazon.com/gp/product/B00E0NTPP4   (please note that we'll 
only be using one of the two relays on that board)

And now to actually answer your question, I threw together an ugly image 
file that shows the physical wiring connections as well as the schematic so 
you can know what it's doing.  I also included a screen print of where I 
have the PTT Com port selected in HS_Soundmodem.  Of course the Com Port 
number will be different on everyone's computer and on top of that, you 
might be using something other than HS_Soundmodem to control your PTT from 
the computer.  But in the following diagram, you can see how I'm setup for 
"Com15":

http://www.qsl.net/k/k4kdr//files/PTT-relay-wiring-plus-schematic.png

... hope that helps!

You also asked about drivers, etc., on a Windows machine.  Other than 
allowing the USB > Serial cable to install whatever it needs to download to 
function, you'll be fine.  The computer has no idea that the RTS signal on 
your serial port is controlling a relay.  So, nothing is needed on the 
computer for the relay itself.

And as for the 5 VDC to power the relay coil, you could certainly use an AC 
adapter of some kind, but I just cut the end off of a short USB printer 
cable and used the red & black wires to give me a convenient 5 VDC from the 
computer (or in my case actually from a multi-port, powered USB hub).

-Scott,  K4KDR


====================================



-----Original Message----- 
From: Tony
Sent: Sunday, October 22, 2017 2:11 PM
To: Scott
Subject: Re: [amsat-bb] Falconsat Success

Scott:

That's exactly what I'm looking for. The fact that it has isolation is a
real plus. Could you pass along a few more details regarding the type of
USB cable used and how you wired the relay to your PTT line on the rig?

I'm not much of a PC guy so every bit helps - never home-brewed a USB PTT.

Thanks Scott

Tony -K2MO


On 10/22/2017 9:39 AM, Scott wrote:
> Congrats, Tony!
>
> The following relay has been working very well for me to handle PTT:
>
> https://www.amazon.com/gp/product/B00E0NTPP4/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
>
> ... I use 5 VDC from a USB cable for the coil voltage with the application
> of that coil voltage being triggered by the serial RTS signal from
> HS_Soundmodem.  The above relay is great for that since the coil circuit 
> is
> controlled by an opto-isolator that can be operated by a low level signal
> like the serial RTS.
>
> The following item sure made it easy to attach a pair of wires to serial
> RTS & ground:
>
> https://www.amazon.com/gp/product/B00WW6P636/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1
>
>
> -Scott,  K4KDR
>
>
>
> ===================================
>
> On Sun, Oct 22, 2017 at 4:39 AM, Tony <dxdx at optonline.net> wrote:
>
>> All:
>>
>> Managed to work Falconsat this morning using UZ7HO's Soundmodem, WISP and
>> VSP. I don't have a PTT circuit so I had to use the rigs MOX function to
>> send file requests. I wouldn't recommend doing that for obvious 
>> reasons --
>> need to build a PTT circuit ASAP.
>>
>> If anyone is interested, this video guide shows the basics on how to 
>> setup
>> Wisp and Soundmodem using HW-VSP.  See: https://www.youtube.com/watch?
>> v=1ahlA-bRb5A
>>
>> 73, Tony -K2MO