Testing TNC-pi


Bob
 

Last night I was able to get APRX running with RPi3b and TNC-pi here on the bench.  This morning, I fired up the setup and noticed it was not transmitting (red LED).  No radio connected right now.

Is there any way I can test the hardware like running a term to see if I can get it to transmit?

I did change to I2C port 3 on inital config.  I can run get_params and see all the settings so I know that program can see it.

thanks
w5evh



David Ranch <dranch@...>
 


Hello Bob,

Are you running the TNC-Pi directly from Aprx (KISS is configured from APRX) or are you running KISS to the Linux side of things?  Testing from the Linux side of things would be easy by using the "beacon" command.  If you're using Aprx, maybe you could configure a beacon that transmits every 60 seconds.

--David
KI6ZHD


On 09/14/2017 04:27 PM, bob@... [Raspberry_Pi_4-Ham_RADIO] wrote:
 

Last night I was able to get APRX running with RPi3b and TNC-pi here on the bench.  This morning, I fired up the setup and noticed it was not transmitting (red LED).  No radio connected right now.

Is there any way I can test the hardware like running a term to see if I can get it to transmit?

I did change to I2C port 3 on inital config.  I can run get_params and see all the settings so I know that program can see it.

thanks
w5evh



 

If you have the pitnc_setparams application, you can write register 15 to a value of 3.  That will cause the TNC-PI to key up for about 10 seconds and send the two modem tones, high, then low.   The RED LED should illuminate while this is going on. 

The only transistor on the TNC-PI, is Q1 which is the PTT switch.  Beware that the regulator and the PTT transistor have the same case.  Q1 is near the 9-pin D-shell socket.  The regulator is at the other end of the board from the D-shell socket.   

The Microchip PIC CPU drives the transmit push-to-talk signal out pin 6 at 3.3v during transmit.  Ground during receive.  The PTT signal goes through R18 and into the base of Q1.  At the same time the CPU drives pin 6 through resistor R19 to the red LED.  Look with a voltmeter on the CPU side of R19 or R18, or on pin 6 of the CPU and you should see a 3.3v high only during transmit.  

On a red TNC-PI, R18 is in between the transistor and the 26 or 40 pin stacking-connector.  I measured R18’s pin on the stacking connector end of the resistor and see it go from 0 at idle to 3.3v during transmit.  The other side of the resistor goes to .66 volts.  Is that the voltage drop across the transistor?  I presume so.  

If you power off and unplug the CPU U3, then power the TNC back up, you can assert PTT by putting 3.3v on pin 6 of socket U3.  If the notch in the U3 socket is up and the expansion/stacking connector is down, then pin 6 is the 6th pin down on the left of the socket.      Pin 14, (5th pin down on the right side) will have VCC, 3.3v.  You can put a solid conductor wire between pin 14 and pin 6 and cause the PTT go fire indefinitely if you need to check this out.  I’m thinking that if this doesn’t work you should check the soldering around the transistor, R18 and R19 and the socket.  

Check the tarpn web site under builders and then TNC-PI (blue button, middle left on the builder page).  There’s lots of information including PCB photos and schematics on there.  

Tadd / KA2DEW
Raleigh NC  FM05pv

“Packet networking over ham radio": http://tarpn.net/t/packet_radio_networking.html

“Raleigh-centric ham radio resources page": http://torborg.com/a




On Sep 15, 2017, at 11:56 PM, David Ranch dranch@... [Raspberry_Pi_4-Ham_RADIO] <Raspberry_Pi_4-Ham_RADIO@...> wrote:


Hello Bob,

Are you running the TNC-Pi directly from Aprx (KISS is configured from APRX) or are you running KISS to the Linux side of things?  Testing from the Linux side of things would be easy by using the "beacon" command.  If you're using Aprx, maybe you could configure a beacon that transmits every 60 seconds.

--David
KI6ZHD


On 09/14/2017 04:27 PM, bob@... [Raspberry_Pi_4-Ham_RADIO] wrote:
 

Last night I was able to get APRX running with RPi3b and TNC-pi here on the bench.  This morning, I fired up the setup and noticed it was not transmitting (red LED).  No radio connected right now.

Is there any way I can test the hardware like running a term to see if I can get it to transmit?

I did change to I2C port 3 on inital config.  I can run get_params and see all the settings so I know that program can see it.

thanks
w5evh





 

I’ve been thinking about this some more.

First step is to check for loose or corroded connections.  Wiggle the microphone connector and the DE9 on the TNC-PI end. 

Your second step should be to see if the radio transmits using a microphone.

If you have another TNC-PI or KPC-3 to test with, isolate the problem to the TNC vs radio.  

If not, then:

We want to test the PTT line to the radio from the DE9 socket of the TNC-PI.  
Disconnect the TNC-PI from the Raspberry PI.  
Hook the radio cable to the TNC-PI DE-9 connector and to the radio’s Mike input.  
See if you can get the radio to PTT by just shorting the bottom of the DE9 pin 3 (middle) to pin 6 (end of the 4).  If you look at the bottom of the TNC-PI (it should not be plugged into the Raspberry PI for this) there are two rows of pins.  Five pins and four pins under the socket.  The middle one of the 5 pins is the PTT wire.   The ground pin is one of the end pins on the 4 pin row.  None of the other pins on the 4-pin row are connected to anything.  So shorting the middle of the 5 pin row to the wrong pin on the 4 pin row is of no consequence.  

If PTT does not work by shorting under the DE9, then look into testing or replacing the microphone/TNC/speaker cable.  

If PTT does work by shorting under the DE9, then proceed to the info in my previous email. 

    Tadd


Tadd / KA2DEW
tadd@...
Raleigh NC  FM05pv

“Packet networking over ham radio": http://tarpn.net/t/packet_radio_networking.html
Local Raleigh ham radio info: http://torborg.com/a  

On Sep 16, 2017, at 10:22 AM, Tadd Torborg <tadd@...> wrote:

If you have the pitnc_setparams application, you can write register 15 to a value of 3.  That will cause the TNC-PI to key up for about 10 seconds and send the two modem tones, high, then low.   The RED LED should illuminate while this is going on. 

The only transistor on the TNC-PI, is Q1 which is the PTT switch.  Beware that the regulator and the PTT transistor have the same case.  Q1 is near the 9-pin D-shell socket.  The regulator is at the other end of the board from the D-shell socket.   

The Microchip PIC CPU drives the transmit push-to-talk signal out pin 6 at 3.3v during transmit.  Ground during receive.  The PTT signal goes through R18 and into the base of Q1.  At the same time the CPU drives pin 6 through resistor R19 to the red LED.  Look with a voltmeter on the CPU side of R19 or R18, or on pin 6 of the CPU and you should see a 3.3v high only during transmit.  

On a red TNC-PI, R18 is in between the transistor and the 26 or 40 pin stacking-connector.  I measured R18’s pin on the stacking connector end of the resistor and see it go from 0 at idle to 3.3v during transmit.  The other side of the resistor goes to .66 volts.  Is that the voltage drop across the transistor?  I presume so.  

If you power off and unplug the CPU U3, then power the TNC back up, you can assert PTT by putting 3.3v on pin 6 of socket U3.  If the notch in the U3 socket is up and the expansion/stacking connector is down, then pin 6 is the 6th pin down on the left of the socket.      Pin 14, (5th pin down on the right side) will have VCC, 3.3v.  You can put a solid conductor wire between pin 14 and pin 6 and cause the PTT go fire indefinitely if you need to check this out.  I’m thinking that if this doesn’t work you should check the soldering around the transistor, R18 and R19 and the socket.  

Check the tarpn web site under builders and then TNC-PI (blue button, middle left on the builder page).  There’s lots of information including PCB photos and schematics on there.  

Tadd / KA2DEW
Raleigh NC  FM05pv

“Packet networking over ham radio": http://tarpn.net/t/packet_radio_networking.html

“Raleigh-centric ham radio resources page": http://torborg.com/a




On Sep 15, 2017, at 11:56 PM, David Ranch dranch@... [Raspberry_Pi_4-Ham_RADIO] <Raspberry_Pi_4-Ham_RADIO@...> wrote:


Hello Bob,

Are you running the TNC-Pi directly from Aprx (KISS is configured from APRX) or are you running KISS to the Linux side of things?  Testing from the Linux side of things would be easy by using the "beacon" command.  If you're using Aprx, maybe you could configure a beacon that transmits every 60 seconds.

--David
KI6ZHD


On 09/14/2017 04:27 PM, bob@... [Raspberry_Pi_4-Ham_RADIO] wrote:
 

Last night I was able to get APRX running with RPi3b and TNC-pi here on the bench.  This morning, I fired up the setup and noticed it was not transmitting (red LED).  No radio connected right now.

Is there any way I can test the hardware like running a term to see if I can get it to transmit?

I did change to I2C port 3 on inital config.  I can run get_params and see all the settings so I know that program can see it.

thanks
w5evh






Bob
 

Hi Tadd, This setup was on the bench with out radio connected.


Bob
 

Ok update:  I got in the mail today another TNC-pi that I ordered for another project.  I put it together and got it on the pi.  New install of OS.  I am trying to reconfigure to use i2c.  When I run getparams I get:

Using Serial port /dev/ttyO1
Device /dev/ttyO1
Com Open Failed: No such file or directory

I can seem to get it to use port /dev/ttyAMA0.  Ive been through all the documentation and I cant figure it out.

How to I get getparams to use /dev/ttyAMA0?

boB
w5evh


John G8BPQ
 

Bob,

Use ./pitnc_getparams 0 0 to access /dev/ttyAMA0. I suspect you are running
./pitnc_getparams 1 0.

The normal usage with the latest version is

./pitnc_getparams
usage for i2c: pitnc_getparams i2bus i2cdevice
usage for Serial /dev/ttyAMA0: pitnc_getparams 0 0
usage for Serial other device: pitnc_getparams device 0

Using 1-5 for device opens /dev/ttyO1 to /dev/ttyO5. This was added for the
BeagleBone Black version of the TNC.


The latest version can be found at

http://www.cantab.net/users/john.wiseman/Downloads/NewPITNCParams.zip()is

73,
John G8BPQ

________________________________________
From: Raspberry_Pi_4-Ham_RADIO@yahoogroups.com
[mailto:Raspberry_Pi_4-Ham_RADIO@yahoogroups.com]
Sent: 17 September 2017 09:12
To: Raspberry_Pi_4-Ham_RADIO@yahoogroups.com
Subject: [Raspberry_Pi_4-Ham_RADIO] Re: Testing TNC-pi

 
Ok update:  I got in the mail today another TNC-pi that I ordered for
another project.  I put it together and got it on the pi.  New install of
OS.  I am trying to reconfigure to use i2c.  When I run getparams I get:

Using Serial port /dev/ttyO1
Device /dev/ttyO1
Com Open Failed: No such file or directory

I can seem to get it to use port /dev/ttyAMA0.  Ive been through all the
documentation and I cant figure it out.

How to I get getparams to use /dev/ttyAMA0?

boB
w5evh


Jim WB9QPM
 

Hi Bob,

If you only want to test the PTT LED, I would open a browser and put the IP number and port. 
(http://192.168.1.10:8008) Click on ports. Click on the beacon link to the port you want to test. Click test button. Watch the LED blink. 

You will also need the HTML directory and files present. The directory is all caps.

This can be done on the PI or thru ethernet on the same sub net.

If the test is good, you also know that BPQ is talking to the TNC.

I hope this helps. I haven't used it for a spell and memory is not as good as it was.

Take care,
Jim WB9QPM



On Sep 17, 2017, at 3:07, bob@... [Raspberry_Pi_4-Ham_RADIO] <Raspberry_Pi_4-Ham_RADIO@...> wrote:

Hi Tadd, This setup was on the bench with out radio connected.



Jim WB9QPM
 

Hi Bob,

After looking through your post, I see your not running BPQ.

Please disregard my last post.

73,
Jim WB9QPM

On Sep 17, 2017, at 8:31, 'jhudson1@...' wb9qpm@... [Raspberry_Pi_4-Ham_RADIO] <Raspberry_Pi_4-Ham_RADIO@...> wrote:

Hi Bob,


If you only want to test the PTT LED, I would open a browser and put the IP number and port. 
(http://192.168.1.10:8008) Click on ports. Click on the beacon link to the port you want to test. Click test button. Watch the LED blink. 

You will also need the HTML directory and files present. The directory is all caps.

This can be done on the PI or thru ethernet on the same sub net.

If the test is good, you also know that BPQ is talking to the TNC.

I hope this helps. I haven't used it for a spell and memory is not as good as it was.

Take care,
Jim WB9QPM



On Sep 17, 2017, at 3:07, bob@... [Raspberry_Pi_4-Ham_RADIO] <Raspberry_Pi_4-Ham_RADIO@...> wrote:

Hi Tadd, This setup was on the bench with out radio connected.





Bob
 

Hi John,

Thanks for the info.  This worked like a charm.  I was able to change the address to 3.

If I setup two TNC-pi's, how do I tell APRX to address each one with APRX? 

Thanks

boB
w5evh

I get by with a little help from my friends!


Bob
 

No worries, you had me going there for a min.  lol  Thans


John G8BPQ
 

Bob,

I’m not familiar with aprx, but generally you have to run i2ckiss to present
the TNC as a kiss interface to the application, either directly or via
kissattach if you are using the Kernel ax.25 software. I’d leave one TNC on
serial so you can leave that setting as it is, and tell the application to
use either the virtual kiss port or the ax.25 device created by i2ckiss.

73,
John


________________________________________
From: Raspberry_Pi_4-Ham_RADIO@yahoogroups.com
[mailto:Raspberry_Pi_4-Ham_RADIO@yahoogroups.com]
Sent: 17 September 2017 22:11
To: Raspberry_Pi_4-Ham_RADIO@yahoogroups.com
Subject: RE: [Raspberry_Pi_4-Ham_RADIO] Re: Testing TNC-pi

 
Hi John,

Thanks for the info.  This worked like a charm.  I was able to change the
address to 3.

If I setup two TNC-pi's, how do I tell APRX to address each one with APRX? 

Thanks

boB
w5evh

I get by with a little help from my friends!