Emma_Jir
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ACT Led

Sun Jan 21, 2018 3:15 pm

I am trying to figure out the led signals on a raspberry Pi 3B.
I understand that the ACT-Led is located next to the wlan-antenna and indicates microsd-activity. Below is the red standby-led. Is there any led that directly indicates wlan-activity like on the Ethernet-Port?

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Re: ACT Led

Sun Jan 21, 2018 3:24 pm

RED LED indicates that the voltage being supplied is good ( above 4.65V I think ) while ever it it on.
GREEN LED indicates SD card being accessed.
LAN port LED's indicate connection and traffic.

There is no LED indicating wif-fi connection/traffic.
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FTrevorGowen
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Re: ACT Led

Sun Jan 21, 2018 3:24 pm

Emma_Jir wrote: I am trying to figure out the led signals on a raspberry Pi 3B.
I understand that the ACT-Led is located next to the wlan-antenna and indicates microsd-activity. Below is the red standby-led. Is there any led that directly indicates wlan-activity like on the Ethernet-Port?
Quick answer No. Although, in principle, it should be possible to connect another LED etc. to a "spare" GPIO and create some monitoring/driving software to do that. If you're really lucky, someone may have done that already.
Trev.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, 2xB2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, and a A+) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

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Re: ACT Led

Sun Jan 21, 2018 3:30 pm

FTrevorGowen wrote:
Sun Jan 21, 2018 3:24 pm
Emma_Jir wrote: I am trying to figure out the led signals on a raspberry Pi 3B.
I understand that the ACT-Led is located next to the wlan-antenna and indicates microsd-activity. Below is the red standby-led. Is there any led that directly indicates wlan-activity like on the Ethernet-Port?
Quick answer No. Although, in principle, it should be possible to connect another LED etc. to a "spare" GPIO and create some monitoring/driving software to do that. If you're really lucky, someone may have done that already.
Trev.
looks like they have.

viewtopic.php?f=63&t=125337

https://github.com/RagnarJensen/PiLEDlights
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Emma_Jir
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Re: ACT Led

Mon Jan 22, 2018 10:57 am

Thanks
pcmanbob wrote:
Sun Jan 21, 2018 3:24 pm
RED LED indicates that the voltage being supplied is good ( above 4.65V I think ) while ever it it on.
Weird. I see it when it's in standby and i have a ticking signal sometimes when i run some commands while the system is up.

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Re: ACT Led

Mon Jan 22, 2018 11:05 am

If the RED LED is flashing or going out completely then it indicates that the voltage being supplied to the pi is to low, either your psu is not up to the job or your cable between the psu & pi needs to be replaced with a better quality one.

if you continue to operate with an under voltage condition you risk SD card corruption and USB devices not working.
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Emma_Jir
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Re: ACT Led

Mon Jan 22, 2018 1:18 pm

pcmanbob wrote:
Mon Jan 22, 2018 11:05 am
If the RED LED is flashing or going out completely then it indicates that the voltage being supplied to the pi is to low, either your psu is not up to the job or your cable between the psu & pi needs to be replaced with a better quality one.

if you continue to operate with an under voltage condition you risk SD card corruption and USB devices not working.
My Rpi worked fine for over a year. The red LED is only on when the device is shutdown and in hibernation. It flashes sometimes when i run commands. It's the 3B+
i don't have any power-draining devices connected to it but it's powered by another machines USB Port. It shows the same behaviour when i run it with the recommended 2A Plug though. I am confused.

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Re: ACT Led

Mon Jan 22, 2018 3:15 pm

A raspberry pi3 should have its Red LED lit all the time not just when its shutdown.

Red LED being off indicates supply voltage to low.

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Emma_Jir
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Re: ACT Led

Mon Jan 22, 2018 9:35 pm

I see. Does everyone use a 2 Ampere plug? I thought this is only necessary if you have any powerhungry devices attatched to it wich isn't the case. And if so it's because of high currents. I read that a Raspberry pi 3B runs on 5.1V. The USB-port provides 5V. I wonder because it worked fine all the time.

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Re: ACT Led

Mon Jan 22, 2018 10:37 pm

If I am running my pi 3B headless I often run it on a 5V 2A switch mode power supply. ( Not a battery charger that many people seem to use ) but if I have things connected to the usb like drives keyboard mouse etc then I use a raspberry official 2.5A power supply.

If you 2A power supply with usb cable can't maintain 5V underload then it is not suitable for powering your pi. It's as simple as that.
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Emma_Jir
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Re: ACT Led

Fri Feb 02, 2018 7:46 pm

pcmanbob wrote:
Mon Jan 22, 2018 10:37 pm
If I am running my pi 3B headless I often run it on a 5V 2A switch mode power supply. ( Not a battery charger that many people seem to use ) but if I have things connected to the usb like drives keyboard mouse etc then I use a raspberry official 2.5A power supply.

If you 2A power supply with usb cable can't maintain 5V underload then it is not suitable for powering your pi. It's as simple as that.
I bought a 2A plug but i power my device over a regular USB Port on my PC instead of a regular Outlet. The standard USB-Voltage is 5V. I think the Led is on when the WLan-Antenna is inactive. But i don't use any power intensive devices like motors or screens so i have no idea why it would drain more than 1A.

Another question: is there any way to establish any form of data connection through the MicroUSB supply port on a Raspberry Pi 3b+ even if it required a lot of skills?
My PC system seems to recognize a Mass Storage Device now and again when the RPi is plugged.

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Re: ACT Led

Fri Feb 02, 2018 8:10 pm

If your red power good LED is not on bright and steady during operation you have a weak power supply.

A Raspberry Pi3B will consume less than 1A if you are not running it too hard and only have basic USB peripherals (non-backlit keyboard, mouse, and a USB flash drive). Push the SoC hard or connect power hungry USB devices and you can easily go well over 1A and might even pull more than 2A. This is why a 2.5A PSU is recommended. I believe the internal polyfuse is rated around 2.6A, so while a PSU rated for more than 2.5A will work, it will not increase the power load capacity of the Pi3 (the polyfuse will cut power if you try to pull more than 2.6A through the system).

Computer USB 2.0 ports will typically output 5V @ 500mA (0.5A) which is not enough to run a Pi3 under much more than idle conditions. USB 3.0 ports can output up to 900mA, which *might* be okay for a lightly loaded Pi3 (but it's still not recommended).

Note that phone charger type power supplies may have poor voltage regulation and not maintain 5V under load. I have tested "5V/2.4A" chargers that dipped well below 5V at only a 1A load. A phone will charge at 4.5V, but that's not enough to run a Pi3. Another potential problem with phone chargers is they often require a micro-USB cable between the PSU and Pi computer, and many standard micro-USB cables have too much internal resistance to deliver the kind of power a Pi3 might require. The USB 2.0 power spec is 5V @ 500mA (5V/0.5A), so that's all some micro-USB cables are designed to deliver. Charging cables that come with smartphones and tablets will usually be better at delivering power. Look for a micro-USB cable with at least 24 AWG power wires, and preferably larger than that (lower AWG = larger wires, so 20 AWG is better than 24).

The official RPF Pi3 power supply is rated at 5.1V/2.5A and has built-in 18 AWG power wires.
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Re: ACT Led

Fri Feb 02, 2018 10:01 pm

Emma_Jir wrote: is there any way to establish any form of data connection through the MicroUSB supply port on a Raspberry Pi 3b+ even if it required a lot of skills?
The microUSB power connector on the Pi3B does not physically have any data lines connected.
I suppose you could solder wires to re-route the data connections from one of the proper USB ports to the microUSB. I've not heard of anyone doing so.
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