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Getting back to the RPi

Michael WA7SKG
 

After a hiatus of about two years or more, I am finally getting back to some RPi projects. The first one is my mobile APRS station. I have an RPi 3B+ with a TNC-Pi mounted in a Smarti-Pi Touch case with a 7" RPi touchscreen. This particular Pi was set up previously for I'm not sure what, but everything is likely quite out of date. This is the first time booting with the 7" touchscreen and the TNC-Pi attached. It was previously used with a 19" HDMI connection. Everything is way too big for this screen. I am powering the package through a Powerwerx USB-Buddy, which accepts 10-30V for a 5V-3A output which goes through a splitter (provided with the Smarti-Pi case) to power both the RPi and the touchscreen. I am getting a bright yellow lightning bolt in the upper right corner of the screen. I opened a terminal window and did the sudo apt update/sudo apt update thing which is taking forever to run.

As this Pi was not previously used for ham applications and the software is likely stale, I am assuming I should download a new image to the SD card. I honestly do not remember whether the current SD card has Raspbian or NOOBS on it and I don't recall how to tell. I've pretty much forgotten almost everything abut the Pi, so I'm really starting from scratch here.

I don't need a whole lot of apps. Just the basic OS and APRS client (probably YAAC). I'll be connecting a GPS puck for time and location. So, it will primarily be doing APRS and occasional conventional packet stuff.

Is there a suggested ham distribution for the Pi available, or should I just install the latest Raspbian, YAAC, and gpsd?

Thanks for any advice to help me get restarted.

73,
Michael WA7SKG

David Ranch
 


Hello Michael,

After a hiatus of about two years or more, I am finally getting back to some RPi projects.

Welcome back.


This is the first time booting with the 7" touchscreen and the TNC-Pi attached. It was previously used with a 19" HDMI connection. Everything is way too big for this screen.

I would recommend to start simple and work your way up.  Disconnect the 7" display and get things working with the 19" monitor at first.  Then, once that's working, find the instructions for the 7" display (they all seem to be different so you'll need to follow their specific recommendations) to get that going.


I am powering the package through a Powerwerx USB-Buddy, which accepts 10-30V for a 5V-3A output which goes through a splitter (provided with the Smarti-Pi case) to power both the RPi and the touchscreen. I am getting a bright yellow lightning bolt in the upper right corner of the screen.

The lighning bolt symbol means it's getting an under-volt condition.  Regardless of what you think of the USB-Buddy quality, it's NOT getting the proper voltage to the Raspberry Pi.  Use a proper Raspberry Pi USB power supply and get that resolved or you'll only have nothing but headaches around stability problems, quirkiness, etc. 


I opened a terminal window and did the sudo apt update/sudo apt update thing which is taking forever to run.

If you run:

   cat /etc/debian_version

What do you see?   If you're setting up a new Pi, I would recommend to use Rasbian Buster which is version 10.2.  If it shows 9.x (Stretch), or 8.x (Jessie), etc... I recommend to install a whole new version from scratch.


As this Pi was not previously used for ham applications and the software is likely stale, I am assuming I should download a new image to the SD card. I honestly do not remember whether the current SD card has Raspbian or NOOBS on it and I don't recall how to tell. I've pretty much forgotten almost everything abut the Pi, so I'm really starting from scratch here.

NOOBS is just an OS installer that would later put different OSes on the card for you.  I generally recommend Raspbian for new users or people who want system stability over specific LInux distribution features, etc.


I don't need a whole lot of apps. Just the basic OS and APRS client (probably YAAC). I'll be connecting a GPS puck for time and location. So, it will primarily be doing APRS and occasional conventional packet stuff.

Raspbian will work well here


Is there a suggested ham distribution for the Pi available, or should I just install the latest Raspbian, YAAC, and gpsd?

I would recommend the latter.  There are some pre-built amateur radio Raspberry Pi images out there these days (check out the archives here in this list) but I would recommend you built it yourself.  It's the only way you're going to learn how it all works.

--David
KI6ZHD

Michael WA7SKG
 

This is a mobile application where everything runs from 12V. My 12V distribution is via PowerPoles, so power supplies built into cigarette lighter plugs are not going to work (don't want huge adapter string), and I have found nothing besides the USB-Buddy that takes the varying voltage of a mobile installation and gives a steady 5V output with enough current for the RPi/TNC/Monitor combination. If someone has a better power supply recommendation, I would love to hear it.

Michael WA7SKG


David Ranch wrote on 12/23/19 6:53 PM:


I am powering the package through a Powerwerx USB-Buddy, which accepts 10-30V for a 5V-3A output which goes through a splitter (provided with the Smarti-Pi case) to power both the RPi and the touchscreen. I am getting a bright yellow lightning bolt in the upper right corner of the screen.
The lighning bolt symbol means it's getting an under-volt condition. Regardless of what you think of the USB-Buddy quality, it's NOT getting the proper voltage to the Raspberry Pi.  Use a proper Raspberry Pi USB power supply and get that resolved or you'll only have nothing but headaches around stability problems, quirkiness, etc.

Michael WA7SKG
 

On the RPi website, I see three options, "Raspbian Buster with desktop and recommended software", "Raspbian Buster with desktop", and "Raspbian Buster Lite". For this purpose, again, basically just running APRS, will the Lite version be adequate? Or should I use the Buster with Desktop image?

tnx,
Michael WA7SKG


David Ranch wrote on 12/23/19 6:53 PM:



I don't need a whole lot of apps. Just the basic OS and APRS client (probably YAAC). I'll be connecting a GPS puck for time and location. So, it will primarily be doing APRS and occasional conventional packet stuff.
Raspbian will work well here

Is there a suggested ham distribution for the Pi available, or should I just install the latest Raspbian, YAAC, and gpsd?
I would recommend the latter.  There are some pre-built amateur radio Raspberry Pi images out there these days (check out the archives here in this list) but I would recommend you built it yourself.  It's the only way you're going to learn how it all works.
--David
KI6ZHD

Clark Martin
 

I use something like some of the following to power a RPi 3 off a 12V LiFePO4 Battery.

<https://www.amazon.com/s?k=12v+5v+step+down&crid=2JEJT78ZCKX7H&sprefix=12v+5v+%2Caps%2C199&ref=nb_sb_ss_i_4_7>


Clark Martin
KK6ISP

On Dec 23, 2019, at 7:40 PM, Michael WA7SKG <wa7skg@...> wrote:

This is a mobile application where everything runs from 12V. My 12V distribution is via PowerPoles, so power supplies built into cigarette lighter plugs are not going to work (don't want huge adapter string), and I have found nothing besides the USB-Buddy that takes the varying voltage of a mobile installation and gives a steady 5V output with enough current for the RPi/TNC/Monitor combination. If someone has a better power supply recommendation, I would love to hear it.

David Ranch
 


Hello Michael,


On the RPi website, I see three options, "Raspbian Buster with desktop and recommended software", "Raspbian Buster with desktop", and "Raspbian Buster Lite". For this purpose, again, basically just running APRS, will the Lite version be adequate? Or should I use the Buster with Desktop image?

Since it sounds like you want to use YACC which is a graphical APRS client, you need an image that runs a windowing client.  You would be best served with "Raspbian Buster with desktop".


To your next question:

>This is a mobile application where everything runs from 12V. My 12V distribution is via PowerPoles, so power supplies built into cigarette lighter plugs are not going to work (don't want huge adapter string), and I have found nothing >besides the USB-Buddy that takes the varying voltage of a mobile installation and gives a steady 5V output with enough current for the RPi/TNC/Monitor combination. If someone has a better power supply recommendation, I would >love to hear it.

You're looking for a DC to DC bridge, DC DC step down converter, UBEC, etc and there are a LOT of options there.  Google "12v to 5v DC DC converter RF quiet" and you'll find lots options and also a lot of complaints.  Why complaints?   This short video frames it well:  https://www.youtube.com/watch?v=0OGvzIJiNmo

Here is one that I've had decent luck with:

   https://www.amazon.com/dp/B01MEF293V/ref=cm_sw_r_em_api_i_c_Nwl2DbBYS45PZ

--David
KI6ZHD

Michael WA7SKG
 

With almost two dozen items shown on that page, is there one in particular you recommend? Do any of these have some kind of case where they would be suitable in a mobile environment?

Michael WA7SKG



Clark Martin wrote on 12/23/19 9:34 PM:

I use something like some of the following to power a RPi 3 off a 12V LiFePO4 Battery.
<https://www.amazon.com/s?k=12v+5v+step+down&crid=2JEJT78ZCKX7H&sprefix=12v+5v+%2Caps%2C199&ref=nb_sb_ss_i_4_7>
Clark Martin
KK6ISP

On Dec 23, 2019, at 7:40 PM, Michael WA7SKG <wa7skg@... <mailto:wa7skg@...>> wrote:

This is a mobile application where everything runs from 12V. My 12V distribution is via PowerPoles, so power supplies built into cigarette lighter plugs are not going to work (don't want huge adapter string), and I have found nothing besides the USB-Buddy that takes the varying voltage of a mobile installation and gives a steady 5V output with enough current for the RPi/TNC/Monitor combination. If someone has a better power supply recommendation, I would love to hear it.

Michael WA7SKG
 

Okay, flashing the "Raspbian Buster with desktop" image to an SD card right now. I'll give that a go and see what happens.

As far as the power supply goes, the USBuddy is basically what you linked to with PowerPoles installed on the 12V wires. I'll have to find an old USB cable to sacrifice to get access to the wires to put a meter on it and verify the voltage. The Kenwood video is interesting. Unfortunately, I do not have access to a Spectrum Analyzer to evaluate all the USB adapters I have. Somehow, with their main customer base being hams, I would kind of assume that Powerwerx would evaluate their products to chose ones with minimum noise. Of course that video only addresses noise, not voltage stability or current handling capability.

Thanks for your comments.

73,
Michael WA7SKG


David Ranch wrote on 12/23/19 9:45 PM:

Hello Michael,

On the RPi website, I see three options, "Raspbian Buster with desktop and recommended software", "Raspbian Buster with desktop", and "Raspbian Buster Lite". For this purpose, again, basically just running APRS, will the Lite version be adequate? Or should I use the Buster with Desktop image?
Since it sounds like you want to use YACC which is a graphical APRS client, you need an image that runs a windowing client.  You would be best served with "Raspbian Buster with desktop".
To your next question:

>This is a mobile application where everything runs from 12V. My 12V
distribution is via PowerPoles, so power supplies built into cigarette lighter plugs are not going to work (don't want huge adapter string), and I have found nothing >besides the USB-Buddy that takes the varying voltage of a mobile installation and gives a steady 5V output with enough current for the RPi/TNC/Monitor combination. If someone has a better power supply recommendation, I would >love to hear it.
You're looking for a DC to DC bridge, DC DC step down converter, UBEC, etc and there are a LOT of options there.  Google "12v to 5v DC DC converter RF quiet" and you'll find lots options and also a lot of complaints.  Why complaints?   This short video frames it well: https://www.youtube.com/watch?v=0OGvzIJiNmo
Here is one that I've had decent luck with:
https://www.amazon.com/dp/B01MEF293V/ref=cm_sw_r_em_api_i_c_Nwl2DbBYS45PZ
--David
KI6ZHD

Kevin Gray <notsome1else@...>
 

Hi Michael

I also use a 7” Touch monitor for y pi, and possibly the case you mentioned.

I had the same “Lightning Bolt” problem you describe.

 

My Cure – stop using the “Y adapter” that came with the monitor.

 

The wires are too small to provide the necessary voltage/current needed for the PI.

Once I switched to two separate cables to power things, the “Lightning Bolt” disappeared.

 

73 Kevin N9VPV

Michael WA7SKG
 

Hi Kevin,

Thanks for that insight. I never thought about the 'Y' cable. Of course that would entail using two 12-5V adapters, increasing an already jumbled mess of wires, but, if that what it takes, so be it. I shall look into it.

Thanks,
Michael WA7SKG

Kevin Gray wrote on 12/24/19 6:00 AM:

Hi Michael
I also use a 7” Touch monitor for y pi, and possibly the case you mentioned.
I had the same “Lightning Bolt” problem you describe.
My Cure – stop using the “Y adapter” that came with the monitor.
The wires are too small to provide the necessary voltage/current needed for the PI.
Once I switched to two separate cables to power things, the “Lightning Bolt” disappeared.
73 Kevin N9VPV

Clark Martin
 

On Dec 23, 2019, at 9:46 PM, Michael WA7SKG <wa7skg@...> wrote:

With almost two dozen items shown on that page, is there one in particular you recommend? Do any of these have some kind of case where they would be suitable in a mobile environment?

Michael WA7SKG



Clark Martin wrote on 12/23/19 9:34 PM:
I use something like some of the following to power a RPi 3 off a 12V LiFePO4 Battery.
<https://www.amazon.com/s?k=12v+5v+step+down&crid=2JEJT78ZCKX7H&sprefix=12v+5v+%2Caps%2C199&ref=nb_sb_ss_i_4_7>