|
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
|
why not combine a buck boost unit close to the pi keep all the Rfi in a cage/rf bag then you feed 12v to that less drop?
Or hack up a higher watt c cable (Amazon Apple laptop charge cable for example)?into a solder usb end
K7mhi? Excuse typos and brevity, sent from a mobile device.
On Monday, July 12, 2021, 2:13 PM, 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
|
Hello Jeremy
My first question is:? Where did you buy the USB cord?
Also 5v 3a is right close to being not enough current for your
pi-4. 4-5a would be better. I mean by the time it reaches your pi
its at max 3a. I don't think it's your cord. 3ft should not* be
enough to shortchange you. That to me would not be that much of a
voltage* drop. Current yes by all means. 3a at 3 feet. That's
quite a lot. So up* your output current for the loss of voltage
from your 3ft cord.
Now have you tried to power this at home with a 5v wall wart with
that 3 ft cord?? I don't think it's the cable. Your right at the
edge of your current with the Powermax 5v 3a supply. Get my
drift?? Up your amperage and try again...
HTH? 73
On 07/12/21 3:13 PM, Jeremy Utley via
groups.io 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
--
73, de Vince KD7TWW
In what year did the FCC mandate the 1500 Watt PEP limit for amateur radio station
power output? - Motorola Corp was formally named
"Galvin Manufacturing Corporation" (1928–1947)
|
How do you "up your output current" in this situation??
Maybe raise the Voltage to get same power on a given conductor? 5.5Vdc won't hurt anything. Beware of smart USB sockets that limit power. 73
On Mon, Jul 12, 2021, 14:42 Vince A < vince@...> wrote:
Hello Jeremy
My first question is:? Where did you buy the USB cord?
Also 5v 3a is right close to being not enough current for your
pi-4. 4-5a would be better. I mean by the time it reaches your pi
its at max 3a. I don't think it's your cord. 3ft should not* be
enough to shortchange you. That to me would not be that much of a
voltage* drop. Current yes by all means. 3a at 3 feet. That's
quite a lot. So up* your output current for the loss of voltage
from your 3ft cord.
Now have you tried to power this at home with a 5v wall wart with
that 3 ft cord?? I don't think it's the cable. Your right at the
edge of your current with the Powermax 5v 3a supply. Get my
drift?? Up your amperage and try again...
HTH? 73
On 07/12/21 3:13 PM, Jeremy Utley via
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
--
73, de Vince KD7TWW
In what year did the FCC mandate the 1500 Watt PEP limit for amateur radio station
power output? - Motorola Corp was formally named
"Galvin Manufacturing Corporation" (1928–1947)
|
On 7/12/2021 4:56 PM, Dave R wrote:
Maybe raise the Voltage to get same power on a given conductor? 5.5Vdc won't hurt anything
I've done some evaluation of R-Pi power supplies and concluded they're basically all crap ;-)?? The white "official" ones still allow undervoltage errors to occur but they do tend to be better because they have integral cables (possibly made with larger gauge wire?) and mostly because they put out 5.3 to 5.5 volts without load, so once you factor in the voltage drop under peak load spikes the undervoltage detector is not triggered.??? It's difficult to make good measurements because most of the inline USB volt/current meters I've tried are pretty inaccurate.?? The best method is with a breakout that allows you to use a known good voltmeter. My SDR webserver is running from a linear power supply for lower noise with power fed through 18ga wires to the GPIO pins.?? I measure the voltage at other GPIO pins and set it to exactly what I want and after doing so it will run for weeks without throttling.?? I realize this bypasses some of the protection circuitry but am OK with that.?? I need to add a UPS to avoid power sags during electrical storms as I'm in a rural area with poor power quality. 73, Bob W9RAN
|
Dave. Certainly 5.5v wont hurt the pi. But he has a voltage drop
because his powerworex is only at max of 3a unit with the 3 ft
cord.? Also what I would do if it were me. I would ohm out the 3
ft cord from one end to the other. And see how much resistance
there is? That way you can calculate the drop in current by Ohm's
law pretty easy. So I don't think it's his USB cord. The cord is
only amplifying his situation...? 73
*Jeremy, You got a Powerwerx USBbuddy? 5v 3a???
It looks like Powerworx does sell/have a 4.8a round model (Panel
mount dual usb 4.8a)? But first. Have you tried the 3ft cord at
home with a 5v wall wart??? I say this because most pi kits come
with a 5v 3a wall wart and a 3 ft cord attached? Mine did when I
bought the pi kit.? Raise the voltage it will increase the current
On 07/12/21 3:56 PM, Dave R via
groups.io wrote:
How do you "up your output current" in this situation??
Maybe raise the Voltage to get same power on a
given conductor? 5.5Vdc won't hurt anything. Beware of smart
USB sockets that limit power. 73
On Mon, Jul 12, 2021,
14:42 Vince A < vince@...> wrote:
Hello Jeremy
My first question is:? Where did you buy the USB
cord?
Also 5v 3a is right close to being not enough current
for your pi-4. 4-5a would be better. I mean by the
time it reaches your pi its at max 3a. I don't think
it's your cord. 3ft should not* be enough to
shortchange you. That to me would not be that much of
a voltage* drop. Current yes by all means. 3a at 3
feet. That's quite a lot. So up* your output current
for the loss of voltage from your 3ft cord.
Now have you tried to power this at home with a 5v
wall wart with that 3 ft cord?? I don't think it's the
cable. Your right at the edge of your current with the
Powermax 5v 3a supply. Get my drift?? Up your amperage
and try again...
HTH? 73
On 07/12/21 3:13 PM, Jeremy Utley via
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
--
73, de Vince KD7TWW
In what year did the FCC mandate the 1500 Watt PEP limit for amateur radio station
power output? - Motorola Corp was formally named
"Galvin Manufacturing Corporation" (1928–1947)
--
73, de Vince KD7TWW
In what year did the FCC mandate the 1500 Watt PEP limit for amateur radio station
power output? - Motorola Corp was formally named
"Galvin Manufacturing Corporation" (1928–1947)
|
toggle quoted message
Show quoted text
On Mon, Jul 12, 2021, 15:20 Vince A < vince@...> wrote:
Dave. Certainly 5.5v wont hurt the pi. But he has a voltage drop
because his powerworex is only at max of 3a unit with the 3 ft
cord.? Also what I would do if it were me. I would ohm out the 3
ft cord from one end to the other. And see how much resistance
there is? That way you can calculate the drop in current by Ohm's
law pretty easy. So I don't think it's his USB cord. The cord is
only amplifying his situation...? 73
*Jeremy, You got a Powerwerx USBbuddy? 5v 3a???
It looks like Powerworx does sell/have a 4.8a round model (Panel
mount dual usb 4.8a)? But first. Have you tried the 3ft cord at
home with a 5v wall wart??? I say this because most pi kits come
with a 5v 3a wall wart and a 3 ft cord attached? Mine did when I
bought the pi kit.? Raise the voltage it will increase the current
On 07/12/21 3:56 PM, Dave R via
wrote:
How do you "up your output current" in this situation??
Maybe raise the Voltage to get same power on a
given conductor? 5.5Vdc won't hurt anything. Beware of smart
USB sockets that limit power. 73
On Mon, Jul 12, 2021,
14:42 Vince A < vince@...> wrote:
Hello Jeremy
My first question is:? Where did you buy the USB
cord?
Also 5v 3a is right close to being not enough current
for your pi-4. 4-5a would be better. I mean by the
time it reaches your pi its at max 3a. I don't think
it's your cord. 3ft should not* be enough to
shortchange you. That to me would not be that much of
a voltage* drop. Current yes by all means. 3a at 3
feet. That's quite a lot. So up* your output current
for the loss of voltage from your 3ft cord.
Now have you tried to power this at home with a 5v
wall wart with that 3 ft cord?? I don't think it's the
cable. Your right at the edge of your current with the
Powermax 5v 3a supply. Get my drift?? Up your amperage
and try again...
HTH? 73
On 07/12/21 3:13 PM, Jeremy Utley via
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
--
73, de Vince KD7TWW
In what year did the FCC mandate the 1500 Watt PEP limit for amateur radio station
power output? - Motorola Corp was formally named
"Galvin Manufacturing Corporation" (1928–1947)
--
73, de Vince KD7TWW
In what year did the FCC mandate the 1500 Watt PEP limit for amateur radio station
power output? - Motorola Corp was formally named
"Galvin Manufacturing Corporation" (1928–1947)
|
Consider making the run from the battery as long as you can by repositioning the PowerWerx USB-Buddy close to the Pi. Use decent gauge wire between the battery and the USB-Buddy. Or consider using a product like??that allows you to set the Pi power at 5.1V. The ncpacket.com community in Raleigh has had good results with the various DROK products.
73 Chuck K4RGN
|
Had the same issue. Went to Anker USB cables. They use higher gauge power conductors than signal conductors in their cables. Available lots of places, including Amazon.
-larry (K8UT)
------ Original Message ------
Sent: 2021-07-12 17:13:38
Subject: [RaspberryPi-4-HamRadio] Quality USB-A to USB-C cable to avoid voltage drop
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
|
FYI – I’m also testing the same setup at home, using my big 35amp switching supply.? The USBBuddy (yes, 5V 3A) is not the problem, that I can confirm.? All other variables being the same – 1ft cord, no voltage warnings, longer cord gives low voltage warnings every few seconds.? Tried the same thing with an Anker 6-port USB-A charging brick, with same results.? I had a similar problem in the past with some Pi-3’s I had, and the minute I found a heavier gauge charging cable, the problem went away entirely. ? From my syslogs running the longer cable: ? Jul 11 20:05:59 ham-pi kernel: [389037.212727] Under-voltage detected! (0x00050005) Jul 11 20:06:03 ham-pi kernel: [389041.382230] Voltage normalised (0x00000000) Jul 11 20:16:58 ham-pi kernel: [389696.583122] Under-voltage detected! (0x00050005) Jul 11 20:17:05 ham-pi kernel: [389702.823184] Voltage normalised (0x00000000) Jul 11 20:20:57 ham-pi kernel: [389935.787009] Under-voltage detected! (0x00050005) Jul 11 20:21:04 ham-pi kernel: [389942.026899] Voltage normalised (0x00000000) Jul 11 20:25:59 ham-pi kernel: [390237.391199] Under-voltage detected! (0x00050005) Jul 11 20:26:03 ham-pi kernel: [390241.551137] Voltage normalised (0x00000000) Jul 11 20:26:57 ham-pi kernel: [390295.632010] Under-voltage detected! (0x00050005) Jul 11 20:27:04 ham-pi kernel: [390301.871992] Voltage normalised (0x00000000) Jul 11 20:39:01 ham-pi kernel: [391019.481875] Under-voltage detected! (0x00050005) Jul 11 20:39:05 ham-pi kernel: [391023.642365] Voltage normalised (0x00000000) Jul 11 20:39:24 ham-pi kernel: [391042.362180] Under-voltage detected! (0x00050005) Jul 11 20:39:28 ham-pi kernel: [391046.521950] Voltage normalised (0x00000000) Jul 11 20:39:30 ham-pi kernel: [391048.602143] Under-voltage detected! (0x00050005) Jul 11 20:39:34 ham-pi kernel: [391052.762069] Voltage normalised (0x00000000) ? Since I swapped back to the shorter cable last night, not a single Under-voltage message. ? Jeremy ?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]> On Behalf Of Vince A Sent: Monday, July 12, 2021 5:21 PM To: [email protected]Subject: Re: [RaspberryPi-4-HamRadio] Quality USB-A to USB-C cable to avoid voltage drop ? Dave. Certainly 5.5v wont hurt the pi. But he has a voltage drop because his powerworex is only at max of 3a unit with the 3 ft cord.? Also what I would do if it were me. I would ohm out the 3 ft cord from one end to the other. And see how much resistance there is? That way you can calculate the drop in current by Ohm's law pretty easy. So I don't think it's his USB cord. The cord is only amplifying his situation...? 73 *Jeremy, You got a Powerwerx USBbuddy? 5v 3a??? It looks like Powerworx does sell/have a 4.8a round model (Panel mount dual usb 4.8a)? But first. Have you tried the 3ft cord at home with a 5v wall wart??? I say this because most pi kits come with a 5v 3a wall wart and a 3 ft cord attached? Mine did when I bought the pi kit.? Raise the voltage it will increase the current ? On 07/12/21 3:56 PM, Dave R via groups.io wrote: How do you "up your output current" in this situation?? Maybe raise the Voltage to get same power on a given conductor? 5.5Vdc won't hurt anything. Beware of smart USB sockets that limit power. 73 ? On Mon, Jul 12, 2021, 14:42 Vince A <vince@...> wrote: Hello Jeremy My first question is:? Where did you buy the USB cord? Also 5v 3a is right close to being not enough current for your pi-4. 4-5a would be better. I mean by the time it reaches your pi its at max 3a. I don't think it's your cord. 3ft should not* be enough to shortchange you. That to me would not be that much of a voltage* drop. Current yes by all means. 3a at 3 feet. That's quite a lot. So up* your output current for the loss of voltage from your 3ft cord. Now have you tried to power this at home with a 5v wall wart with that 3 ft cord?? I don't think it's the cable. Your right at the edge of your current with the Powermax 5v 3a supply. Get my drift?? Up your amperage and try again... HTH? 73 On 07/12/21 3:13 PM, Jeremy Utley via 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
-- 73, de Vince KD7TWW In what year did the FCC mandate the 1500 Watt PEP limit for amateur radio station power output? - Motorola Corp was formally named "Galvin Manufacturing Corporation" (1928–1947)
-- 73, de Vince KD7TWW In what year did the FCC mandate the 1500 Watt PEP limit for amateur radio station power output? - Motorola Corp was formally named "Galvin Manufacturing Corporation" (1928–1947)
|
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
|
This just in. I wonder how much noise it makes. 73
CNX Software: PiSugar S and PiSugar S Pro – Lower cost batteries for Raspberry Pi.
https://www.cnx-software.com/2021/07/12/pisugar-s-and-pisugar-s-pro-lower-cost-batteries-for-raspberry-pi/
|
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
toggle quoted message
Show quoted text
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
|
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
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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
toggle quoted message
Show quoted text
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
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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
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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
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Show quoted text
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
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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
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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
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Anker cables have proven to me to be the best at effectively transferring the power you are paying for. ?They simply wirk.
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vince kd7tww
Dave R
Chuck K4RGN
Larry K8UT
dwfunk4475
Tadd KA2DEW in NC