Re: RealVNC loses connection
Hello Carlos,
You need to give us more details.? Where is your VNC client
computer?? Is it on the internet somewhere and your Raspberry Pi
is behind your home router with a port forward?? If so, it sounds
like your Internet router is timing out the NAT PORTFW connection
because it thinks the connection is idle.? Which VNC client are
you using?? Is it from RealVNC?? If so, do you see any interesting
detail on the client in the $HOME/.vnc/vncviewer.log file?? A an
experiment, you can go under Preferences --> Expert, what are
the settings for KeepAliveInterval and KeepAliveResponseTimeout??
Try HALVING the KeepAliveInterval
value and DOUBLE theKeepAliveResponseTimeout setting
and then re-connect to the Raspberry Pi.? Does that help?
--David
KI6ZHD
On 08/13/2021 09:56 PM, Carlos via
groups.io wrote:
toggle quoted message
Show quoted text
I can't seem to be able to maintain a VNC connection
for more that a few minutes.
Does not matter if the connection is cloud or IP, I am lucky if I
can maintain a connection for 10mts.
I have the router setup to port 5900.? I have checked the
When it disconnects and tries to reconnect I get the following
message.
???? "Attempting to reconnect to VNC Server..."
???? "Times out waiting for response to "keep alive" message"
I am beyond frustrated with this.
Using Linux Mint as the viewer.
I could really use some help with this.
Thanks
Carlos
KE5DFK
|
Hey David,
A micro SD card with a working copy of Raspberry Pi OS has two
partitions on the card:
?? - Partition 1 - FAT32 file system - holds /boot : A windows or
Mac computer can read / write these files
?? - Partition 2 - EXT4 file system - holds all other parts of the
OS, home directories, etc.: A Windows or Mac computer will NOT be
able to see this file system or read/write any of these files
You can see these partitions using the Linux command (here is an
example for a Samsung 16GB micro-SD card):
?? sudo fdisk -l /dev/mmcblk0
?? --
?? Disk /dev/mmcblk0: 14.9 GiB, 15931539456 bytes, 31116288
sectors
?? Units: sectors of 1 * 512 = 512 bytes
?? Sector size (logical/physical): 512 bytes / 512 bytes
?? I/O size (minimum/optimal): 512 bytes / 512 bytes
?? Disklabel type: dos
?? Disk identifier: 0x92f034a6
?? Device???????? Boot Start????? End? Sectors? Size Id
Type
?? /dev/mmcblk0p1?????? 8192??? 93813??? 85622 41.8M? c W95
FAT32 (LBA)
?? /dev/mmcblk0p2????? 94208 31116287 31022080 14.8G 83
Linux
?? --
I think the issue that you're seeing here is an issue with your SD
card *reader* on your other PC.? What *capacity* is your MicroSD
card?? Is it larger than 32GB?? What is the labeling on your SD card
reader? ? Does it have writing on the card showing compatibility
for:
?? - SD
?? - SDHC
?? - SDXC
?? - MMC
If I was to guess, you have a 64GB card and you're reader either
doesn't have or has incomplete SDHC support.? I have been bitten by
older SD card readers mis-reading bigger SD cards and if they seemed
to read ok, writing to them would corrupt the SD card's file
system.? It's really unacceptable that this is possible but I can
personally tell you it *IS* possible and has happened to me a few
times before.? If this is your scenario, I would recommend to
*recycle* that old SD card reader and get something newer that has
proper SD card support to avoid trashing future card events.
--David
KI6ZHD
On 08/13/2021 05:34 PM, David AJ6RE
wrote:
toggle quoted message
Show quoted text
After successfully using my Rpi 4 B+ for a few months
as part of my homebrew mobile manpack rig I decided to back up the
SD card prior to installing a GPS dongle. I did a sudo shutdown -h
now and powered down. When I stuck the SD card it into my PC it
was blank, save for the volume label.?
After failed attempts to recover the data, I flashed a new card,
installed Hampi again, started reconfiguring Flrig etc., Then I
decided to double-check the new card. I did the graceful shutdown
before pulling the card out but evidently wiped that one as well
at some point in the process. All files were gone but for a couple
of text files and the volume label.
Subsequent online research indicates maybe I didn't let the pi
shut down all the way before pulling the card. I did not know to
wait for flashing lights after shutting down. However, I'm pretty
sure I powered it down all the way after several seconds.?After
spending hours flashing cards and looking forward to the prospect
of going back to square one yet again and then reconfiguring the
software again, and hoping it doesn't happen a third time, I am
thinking the pi may just be too fragile a system to rely upon for
emergency/mobile comms. It seems crazy that the SD card should be
so vulnerable to erasure simply by being extracted from the Pi.?
At this point I am planning on just using the Toughbook that I was
using as a keyboard/screen interface to host the software and cut
out the Pi. It's a shame since I've invested countless hours in
getting Hampi up and running.
Has anyone else had this experience?
David AJ6RE??
|
uh NO!? The files are not being erased and the SD card is NOT blank!
The "few" files that you can see are in the BOOT partition and it is formatted as FAT which windoz can see.
The main partition is formatted for Linus, in EXT4 and windoz can not see them.
Be careful because windoz can see this partition as another disk drive and wants to format it. DO NOT FORMAT IT!
There are several ways to backup your SD card:
-david
On Sat, Aug 14, 2021 at 9:08 AM Christopher Rose < kb8uih88@...> wrote: SD card
|
toggle quoted message
Show quoted text
On Aug 14, 2021 9:43 AM, Christopher Rose <kb8uih88@...> wrote: Turn off the pi power supply, unplug it if necessary to make sure the pi is off before pulling as card? On Aug 13, 2021 11:39 PM, "David Harris via groups.io" <v-zonkeh@...> wrote:
The RPi uses a different file system that a PC, which is why we use an “Etcher” program to make a few FS… you’d also need to use that Etcher to make a backup Image of the file system (with files) on your SD card… and then you could use
Etcher to Etch a new card using that pre-populated image (and carry that spare card as your just-in-case SD card.
?
?
?????? -Z-
?
?
From: [email protected] <[email protected]>
On Behalf Of David AJ6RE via groups.io
Sent: Friday, August 13, 2021 5:34 PM
To: [email protected]
Subject: [EXTERNAL] [RaspberryPi-4-HamRadio] SD Cards Erased Upon Removal? #hampi #hardware #pi #raspberrypi #usability
?
After successfully using my Rpi 4 B+ for a few months as part of my homebrew mobile manpack rig I decided to back up the SD card prior to installing a GPS dongle. I did a sudo shutdown -h now and powered down. When I stuck the SD card it
into my PC it was blank, save for the volume label.?
After failed attempts to recover the data, I flashed a new card, installed Hampi again, started reconfiguring Flrig etc., Then I decided to double-check the new card. I did the graceful shutdown before pulling the card out but evidently wiped that one as well
at some point in the process. All files were gone but for a couple of text files and the volume label.
Subsequent online research indicates maybe I didn't let the pi shut down all the way before pulling the card. I did not know to wait for flashing lights after shutting down. However, I'm pretty sure I powered it down all the way after several seconds.?After
spending hours flashing cards and looking forward to the prospect of going back to square one yet again and then reconfiguring the software again, and hoping it doesn't happen a third time, I am thinking the pi may just be too fragile a system to rely upon
for emergency/mobile comms. It seems crazy that the SD card should be so vulnerable to erasure simply by being extracted from the Pi.?
At this point I am planning on just using the Toughbook that I was using as a keyboard/screen interface to host the software and cut out the Pi. It's a shame since I've invested countless hours in getting Hampi up and running.
Has anyone else had this experience?
David AJ6RE??
|
Turn off the pi power supply, unplug it if necessary to make sure the pi is off before pulling as card?
On Aug 13, 2021 11:39 PM, "David Harris via groups.io" <v-zonkeh@...> wrote:
The RPi uses a different file system that a PC, which is why we use an “Etcher” program to make a few FS… you’d also need to use that Etcher to make a backup Image of the file system (with files) on your SD card… and then you could use
Etcher to Etch a new card using that pre-populated image (and carry that spare card as your just-in-case SD card.
?
?
?????? -Z-
?
?
From: [email protected] <[email protected]>
On Behalf Of David AJ6RE via groups.io
Sent: Friday, August 13, 2021 5:34 PM
To: [email protected]
Subject: [EXTERNAL] [RaspberryPi-4-HamRadio] SD Cards Erased Upon Removal? #hampi #hardware #pi #raspberrypi #usability
?
After successfully using my Rpi 4 B+ for a few months as part of my homebrew mobile manpack rig I decided to back up the SD card prior to installing a GPS dongle. I did a sudo shutdown -h now and powered down. When I stuck the SD card it
into my PC it was blank, save for the volume label.?
After failed attempts to recover the data, I flashed a new card, installed Hampi again, started reconfiguring Flrig etc., Then I decided to double-check the new card. I did the graceful shutdown before pulling the card out but evidently wiped that one as well
at some point in the process. All files were gone but for a couple of text files and the volume label.
Subsequent online research indicates maybe I didn't let the pi shut down all the way before pulling the card. I did not know to wait for flashing lights after shutting down. However, I'm pretty sure I powered it down all the way after several seconds.?After
spending hours flashing cards and looking forward to the prospect of going back to square one yet again and then reconfiguring the software again, and hoping it doesn't happen a third time, I am thinking the pi may just be too fragile a system to rely upon
for emergency/mobile comms. It seems crazy that the SD card should be so vulnerable to erasure simply by being extracted from the Pi.?
At this point I am planning on just using the Toughbook that I was using as a keyboard/screen interface to host the software and cut out the Pi. It's a shame since I've invested countless hours in getting Hampi up and running.
Has anyone else had this experience?
David AJ6RE??
|
Just out of curiosity, what OS are you using when attempting to read the SD card (when it showed "blank")?
-Sam KO4KBY
On Fri, Aug 13, 2021 at 8:34 PM David AJ6RE < dc1@...> wrote: After successfully using my Rpi 4 B+ for a few months as part of my homebrew mobile manpack rig I decided to back up the SD card prior to installing a GPS dongle. I did a sudo shutdown -h now and powered down. When I stuck the SD card it into my PC it was blank, save for the volume label.?
After failed attempts to recover the data, I flashed a new card, installed Hampi again, started reconfiguring Flrig etc., Then I decided to double-check the new card. I did the graceful shutdown before pulling the card out but evidently wiped that one as well at some point in the process. All files were gone but for a couple of text files and the volume label.
Subsequent online research indicates maybe I didn't let the pi shut down all the way before pulling the card. I did not know to wait for flashing lights after shutting down. However, I'm pretty sure I powered it down all the way after several seconds.?After spending hours flashing cards and looking forward to the prospect of going back to square one yet again and then reconfiguring the software again, and hoping it doesn't happen a third time, I am thinking the pi may just be too fragile a system to rely upon for emergency/mobile comms. It seems crazy that the SD card should be so vulnerable to erasure simply by being extracted from the Pi.?
At this point I am planning on just using the Toughbook that I was using as a keyboard/screen interface to host the software and cut out the Pi. It's a shame since I've invested countless hours in getting Hampi up and running.
Has anyone else had this experience?
David AJ6RE??
|
Actually...they are not any more "sensitive" to being removed than
other solid-state-devices...which is to say they are NOT as sensitive
as you suggest.
Wait 30 secs or so.....THEN remove it....(just to "be-sure")
es vy 73 om de "baab" w9ya
toggle quoted message
Show quoted text
On Fri, Aug 13, 2021 at 6:34 PM David AJ6RE <dc1@...> wrote:
After successfully using my Rpi 4 B+ for a few months as part of my homebrew mobile manpack rig I decided to back up the SD card prior to installing a GPS dongle. I did a sudo shutdown -h now and powered down. When I stuck the SD card it into my PC it was blank, save for the volume label.
After failed attempts to recover the data, I flashed a new card, installed Hampi again, started reconfiguring Flrig etc., Then I decided to double-check the new card. I did the graceful shutdown before pulling the card out but evidently wiped that one as well at some point in the process. All files were gone but for a couple of text files and the volume label.
Subsequent online research indicates maybe I didn't let the pi shut down all the way before pulling the card. I did not know to wait for flashing lights after shutting down. However, I'm pretty sure I powered it down all the way after several seconds. After spending hours flashing cards and looking forward to the prospect of going back to square one yet again and then reconfiguring the software again, and hoping it doesn't happen a third time, I am thinking the pi may just be too fragile a system to rely upon for emergency/mobile comms. It seems crazy that the SD card should be so vulnerable to erasure simply by being extracted from the Pi.
At this point I am planning on just using the Toughbook that I was using as a keyboard/screen interface to host the software and cut out the Pi. It's a shame since I've invested countless hours in getting Hampi up and running.
Has anyone else had this experience?
David AJ6RE
|
Apologies for the potential double-post.? I waited an hour since my last attempt to send:
Just out of curiosity, what OS are you using when attempting to read the SD card (when it showed "blank")?
?
-Sam KO4KBY
|
Did you try putting the card back in the Raspberry Pi before formatting it?
Linux, which HamPi runs on usually uses a filesystem that windows does not know how to read... It would be the same if you put the drive from a Mac in the PC and tried to read it.
Linux can read almost any file system but Windows can only really read few(FAT, FAT32, ExtFAT, NTFS, etc.) You have to install a driver to get windows to read Linux and Mac partitions and file systems.
You could have probably backed up the SD card with a RAW backup program that backs up the data one for one without having to understand it.
Linux is VERY stable and not fragile. Last I checked about one half of all websites ran on it.
I have been running Lunux for years, and so was not surprised that I could not see my files from windows, but I can understand how it could confuse someone that had no experience with it before.
Linux has it's own backup software built in, and you could back everything up to a USB stick, USB HD, network, or the cloud.
|
I can't seem to be able to maintain a VNC connection for more that a few minutes.
Does not matter if the connection is cloud or IP, I am lucky if I can maintain a connection for 10mts.
I have the router setup to port 5900.? I have checked the
When it disconnects and tries to reconnect I get the following message.
???? "Attempting to reconnect to VNC Server..."
???? "Times out waiting for response to "keep alive" message"
I am beyond frustrated with this.
Using Linux Mint as the viewer.
I could really use some help with this.
Thanks
Carlos
KE5DFK
|
The RPi uses a different file system that a PC, which is why we use an “Etcher” program to make a few FS… you’d also need to use that Etcher to make a backup Image of the file system (with files) on your SD card… and then you could use
Etcher to Etch a new card using that pre-populated image (and carry that spare card as your just-in-case SD card.
?
?
?????? -Z-
?
?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]>
On Behalf Of David AJ6RE via groups.io
Sent: Friday, August 13, 2021 5:34 PM
To: [email protected]
Subject: [EXTERNAL] [RaspberryPi-4-HamRadio] SD Cards Erased Upon Removal? #hampi #hardware #pi #raspberrypi #usability
?
After successfully using my Rpi 4 B+ for a few months as part of my homebrew mobile manpack rig I decided to back up the SD card prior to installing a GPS dongle. I did a sudo shutdown -h now and powered down. When I stuck the SD card it
into my PC it was blank, save for the volume label.?
After failed attempts to recover the data, I flashed a new card, installed Hampi again, started reconfiguring Flrig etc., Then I decided to double-check the new card. I did the graceful shutdown before pulling the card out but evidently wiped that one as well
at some point in the process. All files were gone but for a couple of text files and the volume label.
Subsequent online research indicates maybe I didn't let the pi shut down all the way before pulling the card. I did not know to wait for flashing lights after shutting down. However, I'm pretty sure I powered it down all the way after several seconds.?After
spending hours flashing cards and looking forward to the prospect of going back to square one yet again and then reconfiguring the software again, and hoping it doesn't happen a third time, I am thinking the pi may just be too fragile a system to rely upon
for emergency/mobile comms. It seems crazy that the SD card should be so vulnerable to erasure simply by being extracted from the Pi.?
At this point I am planning on just using the Toughbook that I was using as a keyboard/screen interface to host the software and cut out the Pi. It's a shame since I've invested countless hours in getting Hampi up and running.
Has anyone else had this experience?
David AJ6RE??
|
After successfully using my Rpi 4 B+ for a few months as part of my homebrew mobile manpack rig I decided to back up the SD card prior to installing a GPS dongle. I did a sudo shutdown -h now and powered down. When I stuck the SD card it into my PC it was blank, save for the volume label.?
After failed attempts to recover the data, I flashed a new card, installed Hampi again, started reconfiguring Flrig etc., Then I decided to double-check the new card. I did the graceful shutdown before pulling the card out but evidently wiped that one as well at some point in the process. All files were gone but for a couple of text files and the volume label.
Subsequent online research indicates maybe I didn't let the pi shut down all the way before pulling the card. I did not know to wait for flashing lights after shutting down. However, I'm pretty sure I powered it down all the way after several seconds.?After spending hours flashing cards and looking forward to the prospect of going back to square one yet again and then reconfiguring the software again, and hoping it doesn't happen a third time, I am thinking the pi may just be too fragile a system to rely upon for emergency/mobile comms. It seems crazy that the SD card should be so vulnerable to erasure simply by being extracted from the Pi.?
At this point I am planning on just using the Toughbook that I was using as a keyboard/screen interface to host the software and cut out the Pi. It's a shame since I've invested countless hours in getting Hampi up and running.
Has anyone else had this experience?
David AJ6RE??
|
NEW Hackable HF SDR for the Raspberry Pi by VU2ESE
Hi Everyone,
I just came across this Hackaday.com article about a user-modifiable HF SDR that should cost less than $100 USD for the Raspberry Pi here:?
It comes from the same developer as the ubitx radio, VU2ESE, so points in its favor!
For more info, you can visit these links:
PDF here:?
Message forum thread here:? /g/BITX20/topic/sbitx/83191173?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,20,83191173
GitHub repo here:?
-- - Dave ??
|
Re: FLDIGI 4.1.19 RPi4 GPIO PTT
Thanks Steve, will keep an eye on that other group. So many groups, so little time?
73’s Dave WA5TET?
|
Re: FLDIGI 4.1.19 RPi4 GPIO PTT
Hi Dave,
I reported this problem to Dave Freese, W1HKJ, right after 4.1.19 was released. He promptly fixed it and the fix is in the development release, currently at . Mosts of the Fldigi related posts are in the linuxham groups.io group.
73,
Steve
AG7GN
|
FLDIGI 4.1.19 RPi4 GPIO PTT
Anyone having an issue with GPIO control for PTT on an RPi4 with FLDIGI 4.1.19?? I see that GPIO 25 is set for an output type but unable to key transmitter.? Same GPIO is working with Direwolf without issue.
Thanks,
Dave WA5TET
|
Re: Raspberry Pi Pico as a crystal replacement
Have you made any stability measurements??
Personally I'll stick with the Si5351, simply because they are easy to obtain, program and use.
In any case the cost of shipping exceeds the price of the part from an supplier.
Larry W8LM
|
Raspberry Pi Pico as a crystal replacement
I've tried to output various frequencies from Raspberry Pi Pico, In MicroPython, changed the machine frequency (this automatically programs the PLL), then divided by 2 or more using PIO, to avoid any glitches caused by the running software.
I don't have a good spectrum analyzer, so can not really measure the phase noise. No obvious problems with the signal.
This is not a true synthesizer like Si5351A, mainly because the PLL phase detector requires 5MHz or more. The step between the possible frequencies is in the range of 50..100kHz, with all whole MHz numbers and many x.xMHz numbers covered.
Unfortunately, this is far from the resolution required for WSPR or FT8 signal output. Still an easily programmable crystal replacement for $4 sounds good to me.
73, Mike AF7KR
|
Re: Quality USB-A to USB-C cable to avoid voltage drop
An HF skyloop is an incredible receive only antenna in the city. imho. 73
I operate 75 and 40 but that doesn’t really matter because even with my house turned off completely my noise floor is pretty pathetic.? At field day every year I marvel at what silence sound like. ? I use an FTdx3000 and a fan dipole up in the back yard with 1/2 acre lot.? Lots of neighbors around who could care less about noise from switching power supplies, LED lights, solar panel systems, etc etc.. ? ? Tadd
What bands are you operating on. Thanks. 73 I’m not sure there is NO noise, but there are 40 of them in use in our data network and I’ve heard no complaints. ? They are $15 from Amazon?
and $40 for 10 of them from Alibaba.?
But I can’t figure out how to send Alibaba money.? The web page is always broken in some way late in the purchase. ?
Can anybody buy from these people?? ? ?Tadd
We see linear supplies that waste half the power as heat and smps supplies that raise the noise floor noticeably.
Can you detect any noise from the DROK? Their website isn't very technical. Amazon is famous for selling EMI plagued devices. 73 The acid test for all this is whether the Raspberry PI complains about under-volt.? If the PI doesn’t complain, EVER, you are probably in great shape. ?
Measuring the voltage at the PI makes sense.? Measuring the current doesn’t help much since the PI will draw what it draws. I don’t think longer cables change how much current the Raspberry PI needs and a bigger power supply on the source end won’t change the current the Raspberry PI needs. ?
My solution is to use a 5.2v regulator and a six inch cable to the USB-c plug.? There are a host of inexpensive (< $20) variable output, 8v to 37v input, adjustable output supplies out in the world.? DROK makes a good one which actually has a variable voltage output into a USB-A socket and that’s the one our local radio club uses.? We like that the PI comes on when the radios are powered up.? Having the PI powered up whenever the radios are on is a good thing.? Having the radios powered and the PI not powered can be bad because voltage enough to start up some of the PI’s peripherals can show up on connections between the radios and those peripherals.? So if the PI is powered down and the radios are up, you can get bad glitches in the peripherals. ?
The point is, you need 5.2v at the Raspberry PI.? You can measure the voltage at the 40-pin AUX connector.? Wires drop voltage when the current draw is > 0.? Longer wires drop more voltage and higher current draw causes more voltage drop.? Thinner wires also cause higher voltage drop. ? So, ?if you have a voltage need, and a current need, and length of wire you want to keep the voltage high enough, the length short enough and the wire thick enough. ?
? ?Tadd
On Jul 12, 2021, at 10:15 PM, dwfunk4475 < dwfunk@...> wrote:
Measure the voltage and current at your Pi, don't guess.?
And FYI, power supplies according to? require 5.1 volts.
-david On Mon, Jul 12, 2021, 16:15 Jeremy Utley < jerutley@...> wrote: Hi all in the group! ? Been doing lots of Google searches, and while years ago I found this kind of info for the old micro-USB cables, I haven’t found similar information for USB-C – and I figure the Pi Ham Radio group is my best bet. ? I’ve got a Pi-4 8GB model, with an Argon One M.2 case and Samsung SSD as the boot device.? I’m building out this device for portable logging/digital mode usage when I’m on POTA activations – either by VNC from a tablet, or a small portable screen mounted in my radio case. ? So the problem I have is with voltage drop – I power the Pi via a PowerWerx USB-Buddy – which provides 5v DC @ 3A, connected to a Bioenno LiFePo4 battery.? In my testing here at home, using a 1ft long USB-A to USB-C cable, it works without any problems.? But, I wanted a longer cable, so I went to a 3ft cable from the same maker.? Once I used that cable, I was immediately getting low voltage warnings – so obviously I’m getting voltage drop on the longer cable.? But I’m having trouble finding heavier USB-A to USB-C cables to avoid voltage drop across that length. ? Anybody have knowledge of any good cables that fit the bill??? ? Thanks! ? Jeremy, NQ0M
|
Re: Quality USB-A to USB-C cable to avoid voltage drop
If anyone wants to know if their Pi is complaining about low voltage, here is a short script to run and have a look:
sudo grep Under-voltage /var/log/syslog | wc -l
Output is the number of under voltage alerts in the log, which is rolled over each day.
Also, these things are pretty good for checking the voltage of your power supplies and are pretty accurate.? Some power supplies for the Pi will only output 4.99 volts, some more than they are rated.? Good to check them.
Mark KD0QYN
On Tuesday, July 13, 2021, 12:21:04 PM CDT, Tadd KA2DEW in NC via groups.io <tadd@...> wrote:
The acid test for all this is whether the Raspberry PI complains about under-volt. ?If the PI doesn’t complain, EVER, you are probably in great shape. ?
Measuring the voltage at the PI makes sense. ?Measuring the current doesn’t help much since the PI will draw what it draws. I don’t think longer cables change how much current the Raspberry PI needs and a bigger power supply on the source end won’t change the current the Raspberry PI needs. ?
My solution is to use a 5.2v regulator and a six inch cable to the USB-c plug. ?There are a host of inexpensive (< $20) variable output, 8v to 37v input, adjustable output supplies out in the world. ?DROK makes a good one which actually has a variable voltage output into a USB-A socket and that’s the one our local radio club uses. ?We like that the PI comes on when the radios are powered up. ?Having the PI powered up whenever the radios are on is a good thing. ?Having the radios powered and the PI not powered can be bad because voltage enough to start up some of the PI’s peripherals can show up on connections between the radios and those peripherals. ?So if the PI is powered down and the radios are up, you can get bad glitches in the peripherals. ?
The point is, you need 5.2v at the Raspberry PI. ?You can measure the voltage at the 40-pin AUX connector. ?Wires drop voltage when the current draw is > 0. ?Longer wires drop more voltage and higher current draw causes more voltage drop. ?Thinner wires also cause higher voltage drop. ? So, ?if you have a voltage need, and a current need, and length of wire you want to keep the voltage high enough, the length short enough and the wire thick enough. ?
? ?Tadd
On Jul 12, 2021, at 10:15 PM, dwfunk4475 < dwfunk@...> wrote:
Measure the voltage and current at your Pi, don't guess.?
And FYI, power supplies according to? require 5.1 volts.
-david On Mon, Jul 12, 2021, 16:15 Jeremy Utley < jerutley@...> wrote: Hi all in the group! ? Been doing lots of Google searches, and while years ago I found this kind of info for the old micro-USB cables, I haven’t found similar information for USB-C – and I figure the Pi Ham Radio group is my best bet. ? I’ve got a Pi-4 8GB model, with an Argon One M.2 case and Samsung SSD as the boot device.? I’m building out this device for portable logging/digital mode usage when I’m on POTA activations – either by VNC from a tablet, or a small portable screen mounted in my radio case. ? So the problem I have is with voltage drop – I power the Pi via a PowerWerx USB-Buddy – which provides 5v DC @ 3A, connected to a Bioenno LiFePo4 battery.? In my testing here at home, using a 1ft long USB-A to USB-C cable, it works without any problems.? But, I wanted a longer cable, so I went to a 3ft cable from the same maker.? Once I used that cable, I was immediately getting low voltage warnings – so obviously I’m getting voltage drop on the longer cable.? But I’m having trouble finding heavier USB-A to USB-C cables to avoid voltage drop across that length. ? Anybody have knowledge of any good cables that fit the bill??? ? Thanks! ? Jeremy, NQ0M
|
dwfunk4475
Sam - KO4HBY
jamesraykenney
David Harris
Dave Slotter, W3DJS
David Cummings
Larry Macionski
Dave R