Date   

Re: Looking for a good power supply that will handle a load

Ray Wells
 

Hi Allen,

I wouldn't even try to argue against you for commercial applications where business reputation is crucial.

Ray vk2tv

On 23/3/20 9:13 am, Allen wrote:
Ray,
   When I had my business in the Communications arena I found out very fast about cost savings. I had special cable that I had been ordering and the failure rate was not good. I then found a company that would sweep every cable and it was a little more. The reason I say this is that little cable when it failed would make your product look real bad. And for what a few bucks or pennies. I would use only high end cables with Times Micro, Ubiquity Tough Cable for Cat6, connectors that were only Amphenol.
Last but not least Memory SD card's that were at it's time the highest X that could be purchased. We needed the highest because we had a 4 radio board that ran our firmware and was HD High Density. 3-4 thousand users connected to one AP. Saving pennies or just dollars would shut down a system because of cheap crap.
Allen Higgins
KE8KZO


Re: Looking for a good power supply that will handle a load

Allen
 

Ray,
   When I had my business in the Communications arena I found out very fast about cost savings. I had special cable that I had been ordering and the failure rate was not good. I then found a company that would sweep every cable and it was a little more. The reason I say this is that little cable when it failed would make your product look real bad. And for what a few bucks or pennies. I would use only high end cables with Times Micro, Ubiquity Tough Cable for Cat6, connectors that were only Amphenol.
Last but not least Memory SD card's that were at it's time the highest X that could be purchased. We needed the highest because we had a 4 radio board that ran our firmware and was HD High Density. 3-4 thousand users connected to one AP. Saving pennies or just dollars would shut down a system because of cheap crap.
Allen Higgins
KE8KZO


Re: pitnc_get params gives me "Bad file descriptor

Bill WA4OPQ
 

Fixed!

Exiting YAAC is what it took.

I thank you gentlemen for taking the time to help me.

The good thing to come of this is that if someone should have the same problem in the future it'll be just a Google away.


Re: Looking for a good power supply that will handle a load

Ray Wells
 

I think that's an unnecessary expense, and the hundreds of thousands of RPi's using Class 10 (even worse) consumer grade cards speaks highly of the reliability of those cards, especially if recommended methods to reduce write cycles is followed. Failures are a very low count overall, and their use extends well beyond just the RPi.

But, if your pocket is deep enough, go ahead with expensive cards.

Ray vk2tv

On 23/3/20 5:10 am, John Tetreault (WA1OKB) wrote:
Speaking of corrupted SD Cards.... Don't waste your money on the "consumer grade" garbage.... Look for SLC Industrial grade for a Pi unless you're installing a read only file system.   mouser has some at a reasonable price (they're much more expensive, but SLC cards have about a 300x longer life,)....

https://www.mouser.com/ProductDetail/Greenliant/GLS93MP008G1-I-BZ801?qs=mAH9sUMRCts8ztElgdnNpg%3D%3D


On Sat, Mar 21, 2020, 5:22 PM Ray Wells <vk2tv@exemail.com.au <mailto:vk2tv@exemail.com.au>> wrote:

What Mark says is 100% correct and RPi voltage is probably one of
the most discussed topics on this list, it's been a source of
problems since at least the RPi B.

Something that is discussed a bit less often is the quality of the
USB cable linking the power supply and the RPi, and if you buy
cheap cables online you stand a good chance of buying rubbish with
tinsel thick conductors. The lesson here is to buy the shortest
cable you can, with the thickest conductors, and buy it from a
reputable "local" supplier. That's not a 100% guarantee but it's a
good start.

I've never had a corrupted SD Card but other problems abound with
under voltage, and measuring the voltage at the power supply (or
trusting the power supply label) will not tell you the true
voltage which you need to measure at the appropriate point on the
RPi, with pins 2 or 4 on the header being a good place. I have one
RPi B that has severe ethernet connectivity issues with 5.1V AT
the Pi, but 5.15V fixes it. My headless (command line only) RPi 4
with a 125mm (5") long supply lead from a 5A SMPS returns constant
under voltage messages in dmesg with 5.1V measured at the Pi, but
it behaves itself at 5.2V.

Supply voltage AT the RPi is crucial for reliable operation. You
have been warned again ;-)

HTH

Ray vk2tv

On 22/3/20 6:31 am, Mark Griffith via Groups.Io wrote:
While a power supply that gives enough current to run the Pi and
any other devices attached through the USB ports is necessary,
the hardware is much more sensitive to the input voltage. 
Running a Pi with reduced voltage will ultimately corrupt the SD
card. A power supply rated for 5 volts will many times just
produce 4.8 or 4.9.  There are a few neat little USB voltage
monitors available and they are easy to use and pretty accurate. 
Put just a little load on one of these marginal supplies and the
voltage drops.

If the red power LED is blinking intermittently, this is a sign
the power supply is not cutting it, no matter what it is rated
for in amps. The Pi hardware determines this and it is monitored
at the kernel level.  In Raspbian Buster, it will write an error
to the syslog each time the voltage drops below the preset level,
which is about 4.8 volts, depending upon which web site you want
to believe.

You can have what you would think is a decent 2.5 or 3 amp power
supply, and still get these alerts since the supply is not able
to provide the correct voltage.  I have found that power supplies
that are rated for 5.1 or 5.2 volts work much better.

If you want to check for the voltage alerts, run this one line
command:

sudo grep -a Under-voltage /var/log/syslog | wc -l

This will give you the number over the last day.  The log gets
reset each day at midnight.

Since I have started monitoring this, I have found many power
supplies that don't cut the mustard.  Look for supplies that are
rated for 5.2 volts and 2.5 or 3 amps and you will not have any
problems.

I've included monitoring this metric in the latest PiGate and
PiGate RMS software.  The ideal is none in a 24 hour period, but
sometimes I see one or two.  Before getting better power
supplies, I had seen 500 or more alerts and the Pi seemed to be
running just fine, so you can infer from this what you want.  I
prefer to not see any.  I would guess there is a reason this is
monitored.

Let me know if you have any questions.

Mark
KD0QYN


Re: Looking for a good power supply that will handle a load

Ray Wells
 

+1 for the adjustable smps, especially for anyone who runs their shack/equipment from 12V battery-backed supply. They're but a couple of dollars or so.

Ray vk2tv

On 22/3/20 5:56 pm, Matt 9V1MH/VK3AMH/YF2AAH wrote:
I power mine externally through the GPIO pins - had a lot of trouble finding a supply that could power the 3B+ , GPS, SDR, USB storage and signalink... easy done with a xv to 5v buck converter connected to 2/4 (+ve) & 6 (-ve)
there are plenty that allow variable output V to be varied.


Re: pitnc_get params gives me "Bad file descriptor

Bill WA4OPQ
 

I'm running YAAC. It was not disabled.

When I get it reassembled I'll make sure not to have it running.


Re: pitnc_get params gives me "Bad file descriptor

Mat Murdock
 

Google is my friend, and I have learned something today.  :)

If you disable Bluetooth on a Pi3 then /dev/AMA0 starts working as does /dev/serial0

ttyAMA0 can be the Tx, Rx pins for the Raspberry. But for the Raspberry Pi 3b it was used for the Bluetooth. Because of this, pins 8 & 10 were using the miniUART which is labeled ttyS0.
So to answer you question, it can refer to pins 8 and 10 if you disable the Bluetooth. It is both the RX and TX pins as it refers to the device it self, which contains both pins.
For posterity, to disable Bluetooth you edit /boot/config.txt and add "dtoverlay=pi3-disable-bt" to the bottom.

Mat
 


Re: pitnc_get params gives me "Bad file descriptor

John G8BPQ
 

What software are you using to send to aprs?

You mustn't be running any other software that accesses the TNC  when you run pitnc_getparams.

73,
John

On 22/03/2020 19:06, Bill WA4OPQ wrote:

I have the symbolic link

lrwxrwxrwx 1 root root 5 Mar 21 23:22 /dev/serial0 -> ttyS0
lrwxrwxrwx 1 root root 7 Mar 21 23:22 /dev/serial1 -> ttyAMA0
 
The teensy software was loaded and I've confirmed transmission with aprs.fi.
And I was planning to go over it with a fine tooth comb this afternoon. Maybe a cold solder joint?


Re: pitnc_get params gives me "Bad file descriptor

Mat Murdock
 

So, two items, one is for my own information and probably directed to Mark.  I do have a /dev/ttyAMA0 on my Pi, however it doesn't seem to respond to anything, however /dev/ttyS0 does appear and does respond.  There is no /dev/serial either.  OS Raspbian Lite.

For Bill, when you power on your Pi, do the lights cycle on the TNC?  What distribution are you using?

Mat


Re: pitnc_get params gives me "Bad file descriptor

Bill WA4OPQ
 

I have the symbolic link

lrwxrwxrwx 1 root root 5 Mar 21 23:22 /dev/serial0 -> ttyS0
lrwxrwxrwx 1 root root 7 Mar 21 23:22 /dev/serial1 -> ttyAMA0
 
The teensy software was loaded and I've confirmed transmission with aprs.fi.
And I was planning to go over it with a fine tooth comb this afternoon. Maybe a cold solder joint?


Re: Looking for a good power supply that will handle a load

Mark Griffith
 

Eh, I've been using the same PNC 32GB Class 10 SD card for more than 4 years. This card started life on an old Pi 2, then to a Pi 3 and now to a Pi 4.  I have re-imaged it many times, installed and uninstalled many many software packages on it, and done all the PiGate development work on this same card with absolutely zero problems.  It sits here sending and receiving email messages all day and night, and is always available when I try to login.  Total reliability for more then 4 years.

One day, just like a hard disk, it will fail.  But I have backups.

I'd say, from my experience, don't waste your money on "premiere" cards.  Just make sure it is a Class 10 card.

My 2 cents.

Mark
KD0QYN


On Sunday, March 22, 2020, 1:10:25 PM CDT, John Tetreault (WA1OKB) <john.h.tetreault@...> wrote:


Speaking of corrupted SD Cards.... Don't waste your money on the "consumer grade" garbage.... Look for SLC Industrial grade for a Pi unless you're installing a read only file system.   mouser has some at a reasonable price (they're much more expensive, but SLC cards have about a 300x longer life,)....

On Sat, Mar 21, 2020, 5:22 PM Ray Wells <vk2tv@...> wrote:
What Mark says is 100% correct and RPi voltage is probably one of the most discussed topics on this list, it's been a source of problems since at least the RPi B.

Something that is discussed a bit less often is the quality of the USB cable linking the power supply and the RPi, and if you buy cheap cables online you stand a good chance of buying rubbish with tinsel thick conductors. The lesson here is to buy the shortest cable you can, with the thickest conductors, and buy it from a reputable "local" supplier. That's not a 100% guarantee but it's a good start.

I've never had a corrupted SD Card but other problems abound with under voltage, and measuring the voltage at the power supply (or trusting the power supply label) will not tell you the true voltage which you need to measure at the appropriate point on the RPi, with pins 2 or 4 on the header being a good place. I have one RPi B that has severe ethernet connectivity issues with 5.1V AT the Pi, but 5.15V fixes it. My headless (command line only) RPi 4 with a 125mm (5") long supply lead from a 5A SMPS returns constant under voltage messages in dmesg with 5.1V measured at the Pi, but it behaves itself at 5.2V.

Supply voltage AT the RPi is crucial for reliable operation. You have been warned again ;-)

HTH

Ray vk2tv

On 22/3/20 6:31 am, Mark Griffith via Groups.Io wrote:
While a power supply that gives enough current to run the Pi and any other devices attached through the USB ports is necessary, the hardware is much more sensitive to the input voltage.  Running a Pi with reduced voltage will ultimately corrupt the SD card.  A power supply rated for 5 volts will many times just produce 4.8 or 4.9.  There are a few neat little USB voltage monitors available and they are easy to use and pretty accurate.  Put just a little load on one of these marginal supplies and the voltage drops.

If the red power LED is blinking intermittently, this is a sign the power supply is not cutting it, no matter what it is rated for in amps.  The Pi hardware determines this and it is monitored at the kernel level.  In Raspbian Buster, it will write an error to the syslog each time the voltage drops below the preset level, which is about 4.8 volts, depending upon which web site you want to believe. 

You can have what you would think is a decent 2.5 or 3 amp power supply, and still get these alerts since the supply is not able to provide the correct voltage.  I have found that power supplies that are rated for 5.1 or 5.2 volts work much better.

If you want to check for the voltage alerts, run this one line command:

sudo grep -a Under-voltage /var/log/syslog | wc -l

This will give you the number over the last day.  The log gets reset each day at midnight.

Since I have started monitoring this, I have found many power supplies that don't cut the mustard.  Look for supplies that are rated for 5.2 volts and 2.5 or 3 amps and you will not have any problems.

I've included monitoring this metric in the latest PiGate and PiGate RMS software.  The ideal is none in a 24 hour period, but sometimes I see one or two.  Before getting better power supplies, I had seen 500 or more alerts and the Pi seemed to be running just fine, so you can infer from this what you want.  I prefer to not see any.  I would guess there is a reason this is monitored.

Let me know if you have any questions.

Mark
KD0QYN



Re: pitnc_get params gives me "Bad file descriptor

Mark Griffith
 

Your TNC is not getting seen by the OS.  When it boots, it will create a symbolic link from /dev/serial0 to /dev/ttyAMA0, which is the TNC.  If this link is not created, I'll bet /dev/ttyAMA0 is also not there.

root@PiGateDev:~# ll /dev/serial0
lrwxrwxrwx 1 root root 7 Mar 14 01:09 /dev/serial0 -> ttyAMA0

root@PiGateDev:~# ll /dev/ttyAMA0
crw-rw---- 1 root dialout 204, 64 Mar 14 01:09 /dev/ttyAMA0

If this is the case, the TNC is bad.  You must have made a mistake building it.  Did you upload the Teensy software to the TNC?

Mark
KD0QYN


On Sunday, March 22, 2020, 1:27:09 PM CDT, Bill WA4OPQ <wa4opq@...> wrote:


I pasted your command. sudo ./pitnc_getparams /dev/ttyS0 0   Still the same results, Bad file descriptor


Re: pitnc_get params gives me "Bad file descriptor

Bill WA4OPQ
 

I pasted your command. sudo ./pitnc_getparams /dev/ttyS0 0   Still the same results, Bad file descriptor


Re: Looking for a good power supply that will handle a load

John Tetreault (WA1OKB)
 

Speaking of corrupted SD Cards.... Don't waste your money on the "consumer grade" garbage.... Look for SLC Industrial grade for a Pi unless you're installing a read only file system.   mouser has some at a reasonable price (they're much more expensive, but SLC cards have about a 300x longer life,)....

On Sat, Mar 21, 2020, 5:22 PM Ray Wells <vk2tv@...> wrote:
What Mark says is 100% correct and RPi voltage is probably one of the most discussed topics on this list, it's been a source of problems since at least the RPi B.

Something that is discussed a bit less often is the quality of the USB cable linking the power supply and the RPi, and if you buy cheap cables online you stand a good chance of buying rubbish with tinsel thick conductors. The lesson here is to buy the shortest cable you can, with the thickest conductors, and buy it from a reputable "local" supplier. That's not a 100% guarantee but it's a good start.

I've never had a corrupted SD Card but other problems abound with under voltage, and measuring the voltage at the power supply (or trusting the power supply label) will not tell you the true voltage which you need to measure at the appropriate point on the RPi, with pins 2 or 4 on the header being a good place. I have one RPi B that has severe ethernet connectivity issues with 5.1V AT the Pi, but 5.15V fixes it. My headless (command line only) RPi 4 with a 125mm (5") long supply lead from a 5A SMPS returns constant under voltage messages in dmesg with 5.1V measured at the Pi, but it behaves itself at 5.2V.

Supply voltage AT the RPi is crucial for reliable operation. You have been warned again ;-)

HTH

Ray vk2tv

On 22/3/20 6:31 am, Mark Griffith via Groups.Io wrote:
While a power supply that gives enough current to run the Pi and any other devices attached through the USB ports is necessary, the hardware is much more sensitive to the input voltage.  Running a Pi with reduced voltage will ultimately corrupt the SD card.  A power supply rated for 5 volts will many times just produce 4.8 or 4.9.  There are a few neat little USB voltage monitors available and they are easy to use and pretty accurate.  Put just a little load on one of these marginal supplies and the voltage drops.

If the red power LED is blinking intermittently, this is a sign the power supply is not cutting it, no matter what it is rated for in amps.  The Pi hardware determines this and it is monitored at the kernel level.  In Raspbian Buster, it will write an error to the syslog each time the voltage drops below the preset level, which is about 4.8 volts, depending upon which web site you want to believe. 

You can have what you would think is a decent 2.5 or 3 amp power supply, and still get these alerts since the supply is not able to provide the correct voltage.  I have found that power supplies that are rated for 5.1 or 5.2 volts work much better.

If you want to check for the voltage alerts, run this one line command:

sudo grep -a Under-voltage /var/log/syslog | wc -l

This will give you the number over the last day.  The log gets reset each day at midnight.

Since I have started monitoring this, I have found many power supplies that don't cut the mustard.  Look for supplies that are rated for 5.2 volts and 2.5 or 3 amps and you will not have any problems.

I've included monitoring this metric in the latest PiGate and PiGate RMS software.  The ideal is none in a 24 hour period, but sometimes I see one or two.  Before getting better power supplies, I had seen 500 or more alerts and the Pi seemed to be running just fine, so you can infer from this what you want.  I prefer to not see any.  I would guess there is a reason this is monitored.

Let me know if you have any questions.

Mark
KD0QYN



Re: Looking for a good power supply that will handle a load

bbillp
 

I purchased the Official High Power Pi-4 AD to DC power adapter and cut off the Pi-4 connector end and soldered a female USB onto the bare end. No voltage faults now.
Bill acj


Re: pitnc_get params gives me "Bad file descriptor

Mat Murdock
 

I just did a fresh install of Raspian Lite and I don't have a /dev/serial0.  I do have a /dev/ttyS0 though.  Anyway, give it a go.  I noticed you were missing the S0 when you posted your command.

pi@raspberrypi:~ $ sudo ./pitnc_getparams /dev/ttyS0 0
pitnc_getparams Version 0.0.0.5
 
Using Serial port /dev/ttyS0
 
   TNC Software Version           6
01 TXDelay - Zero means use ADC  50
02 Persistance                   64
03 Slottime (in 10 mS)           10
04 TXTail                         3
05 Full Duplex - Not used         0
06 Our Channel (Hex)             ff
07 I2C Address (0 = async) Hex   ff
08 Mode Speed                  1200
09 RX Level (Config)            200
10 TX Level                     255
11 RX Level (Actual)            200
13 Centre Freq                 2550
8 6 32 40 a 3 0 ff ff c c8 ff c8 ff 79 c0 sum 0 


Re: pitnc_get params gives me "Bad file descriptor

Bill WA4OPQ
 

And Bad file descriptor is showing up again after two "retrying.." using   sudo ./pitnc_getparams /dev/serial0 0
 


Re: pitnc_get params gives me "Bad file descriptor

Bill WA4OPQ
 

JP3 and JP 4 are in.  enable_uart=1 is in the config.txt file

sudo ./pitnc_getparams /dev/serial0 0  gives retrying... retrying...


Re: pitnc_get params gives me "Bad file descriptor

Bill WA4OPQ
 

One more thing...

The TNC is currently transmitting (showing up on aprs.fi while APRS-IS disabled)

But It's not receiving, which is why i wanted to see the params.


Re: pitnc_get params gives me "Bad file descriptor

Mark Griffith
 

/dev/tty0 is the wrong port for the TNC.  Use /dev/serial0

Mark
KD0QYN


On Sunday, March 22, 2020, 12:14:21 PM CDT, Bill WA4OPQ <wa4opq@...> wrote:


A slight change, no longer seeing "Bad file descriptor"
 
sudo ./pitnc_getparams /dev/tty0 0

pitnc_getparams Version 0.0.0.5
Using Serial port /dev/tty0
retrying...
retrying...
retrying...

 ./pitnc_getparams /dev/tty0 0
 
pitnc_getparams Version 0.0.0.5
Using Serial port /dev/tty0
Device /dev/tty0
Com Open Failed: Permission denied

ls -l /dev/ser*
lrwxrwxrwx 1 root root 5 Mar 21 23:22 /dev/serial0 -> ttyS0
lrwxrwxrwx 1 root root 7 Mar 21 23:22 /dev/serial1 -> ttyAMA0
 

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