[App_rpt-users] SimpleUSB gpio?

[David McGough]

Hi Stephen,

While the CM108/CM119 audio chips found in URI's are powered from the +5V
USB source, they contain an internal +3.3V regulator and are internally
completely 3.3V logic....So, you'll never see more than +3.3V as a
logic "high" level coming from the GPIO pins.



73, David KB4FXC


On Thu, 4 Aug 2016, Stephen - K1LNX wrote:

> An update on this, and I've learned something that was not so obvious to
> me, so I'll put this out there in case someone runs into this in the future.
> 
> Consider my dilemma.. I am using an RTCM to drive a pair of radios in full
> duplex mode. I needed to drive a relay (or MOSFET board in my case, more on
> that in a bit) to turn a fan on the transmit radio on and off as needed.
> Considering there are no GPIO's on the RTCM, I had a URIx also connected
> that I planned on using for another application that I thought I could tap
> the GPIO off of. I found Kyle, K0KN's excellent fan script, as well as this
> resource:
> 
> http://latinovoip.net/allstar-and-the-gpio-fan-script-for-dmk-engineering-uri/
> 
> I elected to use the version linked above, and got everything configured,
> but discovered my cop,62 commands were not working to toggle the GPIO line
> on the URI. I tried a variety of differing configs and troubleshooting
> methods, none of which worked, when I finally tried to issue the cop
> command from the node that is on the URI instead as a test, and what do you
> know, it worked.
> 
> It also appears that GPIO support was added into chan_simpleusb as of
> revision 1060:
> http://svn.ohnosec.org/viewvc/projects/allstar/astsrc-1.4.23-pre/trunk/asterisk/channels/chan_simpleusb.c?revision=1060&root=svn&view=markup
> 
> On the hardware side, I had issues with the relay board I was using. I was
> seeing approximately 3.25 v when the GPIO was toggled to an on state on the
> URI. That was not enough to "trigger" the relay board to fire the relay, it
> needs right at a solid 5 volts. Rather than add another piece of hardware
> to ramp the voltage up, I ran across this on Ebay:
> 
> http://www.ebay.com/itm/301357646243?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
> 
> This is a 3 channel MOSFET board that will switch the output on above 2.5v,
> off at ground. Perfect for my application. I have yet to test it, but have
> high confidence it will work just fine for my intended purpose.
> 
> On the software side, I had to make a few small changes in the scripts that
> I got from the link above, most notably:
> 
> run_app_rpt_fan.sh
> /etc/asterisk/local/app_rpt_fan.sh 1999 > /dev/null & ; change 1999 to the
> node number that is attached to the URI, a private node in my case
> 
> app_rpt_fan.sh
> PTTSTATE="/tmp/RPT_TXKEYED1999" ; change from the $1 variable to the node
> number that is attached to the RTCM instead
> 
> There are more likely easier solutions than what I've provided above, but
> this does work as intended now. After 10 seconds, GPIO1 goes high, goes
> back to ground after 10 minutes. An even easier solution would be to
> probably just use a snapdisc and have it fire on a certain temperature, but
> I wanted more granular control so that wasn't really an option. I could
> have also elected to use a Raspberry Pi and tap one of the GPIO's there
> instead, but my AllStar server is built on an x86 box running other
> applications so that wasn't really an option either.
> 
> I'd like to explore the possibility of maybe having chan_voter talk to the
> GPIO's in chan_usb or simpleusb. We could say add a config to the
> voter.conf file for the particulars for example. Not sure what this would
> take, but curious if it could be done?
> 
> Hope this helps someone in the future...
> 
> 73
> Stephen
> K1LNX
> 
> 
> On Thu, Aug 4, 2016 at 3:32 AM, Stephen - K1LNX <k1lnx at k1lnx.net> wrote:
> 
> > I'm trying to manipulate a GPIO pin off of a URIx and I am not able to get
> > it to work for whatever reason. If I send a cop,62 command to toggle it, it
> > does not change the state.
> >
> > I found this message from Jim that was posted in June 2011:
> >
> > http://ohnosec.org/pipermail/app_rpt-users/2011-June/002725.html
> >
> > Does anyone know if this was ever implemented? This was quite some time
> > ago.
> >
> > I might be able to use usbradio instead for my application, but prefer
> > SimpleUSB as it's easier to implement.
> >
> > 73
> > Stephen
> > K1LNX
> >
>