Go to advanced search

by seanspotatobusiness
Sat Sep 01, 2018 12:17 pm
Forum: Troubleshooting
Topic: Pi doesn't boot when pins 5 and 6 are momentarily shorted
Replies: 16
Views: 1543

Re: Pi doesn't boot when pins 5 and 6 are momentarily shorted

gordon77 wrote:
Sat Sep 01, 2018 12:13 pm
It may need to be enabled by simply adding the following line to /boot/config.txt:

dtoverlay=gpio-shutdown
Is that for shutting down the Pi or turning it on? I'm only trying to get a button to turn on the Pi. I don't want the button to also trigger shutdown.
by seanspotatobusiness
Sat Sep 01, 2018 11:59 am
Forum: Troubleshooting
Topic: Pi doesn't boot when pins 5 and 6 are momentarily shorted
Replies: 16
Views: 1543

Pi doesn't boot when pins 5 and 6 are momentarily shorted

I read that the Pi 3 B can be turned on by shorting physical pins 5 and 6 but mine doesn't respond to this. It powers on if I disconnect and reconnect power but that's a bit less convenient and I wanted to use a momentary switch to trigger the power-on. Edit: I don't want to use the button to shutdo...
by seanspotatobusiness
Fri Aug 31, 2018 7:38 pm
Forum: Beginners
Topic: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected
Replies: 23
Views: 1376

Re: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected

You know that, if you measure the current at the mA range. You add effectively a +/- 2.5 ohm resistor in series with your led. But the exect value for you I cant tell, because that is missing in the manual of you ddm. So, I think it is higher in you case. I know and I have more than one DMM so I co...
by seanspotatobusiness
Fri Aug 31, 2018 7:07 pm
Forum: Beginners
Topic: Adding indicator LED to know when my Pi has finished doing something in the terminal
Replies: 3
Views: 290

Re: Adding indicator LED to know when my Pi has finished doing something in the terminal

import RPi.GPIO as GPIO # Import Raspberry Pi GPIO library from time import sleep # Import the sleep function from the time module import subprocess GPIO.setwarnings(False) # Ignore warning for now GPIO.setmode(GPIO.BOARD) # Use physical pin numbering GPIO.setup(10, GPIO.OUT, initial=GPIO.LOW) # Se...
by seanspotatobusiness
Fri Aug 31, 2018 6:53 pm
Forum: Beginners
Topic: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected
Replies: 23
Views: 1376

Re: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected

Like I said, the voltage would need to be over 3.4 V to draw more than 16 mA and according to my DMM it's 3.27 V and my DMM is accurate to less than 0.001 so I definitely trust it to 0.01 so I don't think it has drawn more than 16 mA. I will investigate by choosing another pin to light with a red L...
by seanspotatobusiness
Fri Aug 31, 2018 5:32 pm
Forum: Beginners
Topic: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected
Replies: 23
Views: 1376

Re: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected

I've determined that the source of the problem is the identities/naming of the pins. The convention in 'gpio mode 10 out' is using the "wPi" pin numbers but I thought it was using physical pin numbers. When I start using "wPi" numbers instead, my LED lights as expected. The voltage drops to 3.02 V e...
by seanspotatobusiness
Fri Aug 31, 2018 4:45 pm
Forum: Beginners
Topic: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected
Replies: 23
Views: 1376

Re: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected

As you connected an LED to the gpio pin without a current limiting resistor your LED tried to draw more current than your gpio pin could supply hence the reduced voltage measured on the gpio pin But it could also have damaged the gpio due to the attempt to draw more than 16mA from the gpio pin, if ...
by seanspotatobusiness
Fri Aug 31, 2018 3:54 pm
Forum: Beginners
Topic: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected
Replies: 23
Views: 1376

Re: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected

Edit: also pin 10 voltage is staying at 3.3 V even when I use command 'gpio write 10 0'. If I do 'gpio read 10' it comes back as 0 but if I check with my DMM, the pin is still at 3.3 V. It's very possible that you blow up the output of that pin. Because you connected the led without a resistor. So,...
by seanspotatobusiness
Fri Aug 31, 2018 1:35 pm
Forum: Beginners
Topic: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected
Replies: 23
Views: 1376

Re: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected

But like I said, the voltage across the LED dropped to 2.3 V. The GPIO pins are meant to be able to safely put out 16 mA so the voltage shouldn't drop below ~3.3 V because the LED will not allow anywhere near that current at 3.3 V. If my complaint was that my LED wasn't lighting and the voltage was ...
by seanspotatobusiness
Fri Aug 31, 2018 11:45 am
Forum: Beginners
Topic: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected
Replies: 23
Views: 1376

Re: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected

You ALWAYS need a series resistor with any kind of LED's The PI's GPIO's are NOT compatible with white or blue LED's, with a forward voltage larger than 3.3V, use a transistor to drive these with 5V. I don't think that makes any sense. At 3.3 V, 7.5 mA flow. I neither need a resistor nor a higher v...
by seanspotatobusiness
Fri Aug 31, 2018 11:05 am
Forum: Beginners
Topic: GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected
Replies: 23
Views: 1376

GPIO pin not lighting LED; voltage drops when LED is connected with only ~7 mA draw expected

I'm trying to light a blue LED with my GPIO pins. I set pin 10 to out and high using the CLI. I can confirm with my DMM that the voltage is about 3.3 V between pins 9 (GND) and 10. When I connect my LED, the voltage drops to 2.3 V and the LED just barely lights but you can only see that it's lit by ...
by seanspotatobusiness
Fri Aug 31, 2018 10:32 am
Forum: Beginners
Topic: Unable to set GPIO pins using gpio command
Replies: 2
Views: 318

Re: Unable to set GPIO pins using gpio command

You've got the one-wire (w1-gpio) driver enabled which uses GPIO4 (Pin 7/WiringPi 7)? Check in /boot/config.txt for w1-gpio and remove or comment it out if it's there. (or use the configration utility or raspi-config -> interfacing to disable w1 and reboot. Unfortunately there's nothing in /boot/co...
by seanspotatobusiness
Fri Aug 31, 2018 7:10 am
Forum: Beginners
Topic: Unable to set GPIO pins using gpio command
Replies: 2
Views: 318

Unable to set GPIO pins using gpio command

I'm having problems trying to set my GPIO pins. Below you can see I entered commands to set pin 7 high but when I read the status of the pin it's still set to 0. Any idea why?

Code: Select all

$ gpio mode 7 out
$ gpio write 7 1
$ gpio read 7
0
by seanspotatobusiness
Thu Aug 30, 2018 8:07 pm
Forum: Off topic discussion
Topic: Deleting threads without making any kind of contact is obnoxious, FYI.
Replies: 6
Views: 3716

Deleting threads without making any kind of contact is obnoxious, FYI.

I think it's rude and unnecessary to just delete a thread without even so much as PM as to why. Now I don't even know whether there were any useful responses. Thanks for nothing.
by seanspotatobusiness
Fri Aug 24, 2018 9:06 pm
Forum: Beginners
Topic: How to make QR codes directly on the Pi (not using an online service)?
Replies: 1
Views: 191

Re: How to make QR codes directly on the Pi (not using an online service)?

The answer is a CLI utility called qrencode which can be installed from the repository!
by seanspotatobusiness
Fri Aug 24, 2018 8:48 pm
Forum: Beginners
Topic: How to make QR codes directly on the Pi (not using an online service)?
Replies: 1
Views: 191

How to make QR codes directly on the Pi (not using an online service)?

What's the easiest to generate QR codes on a Pi? I see there are some libraries for people to write their own software to make QR codes but surely there is suitable software already? I found an old extension for Libre Office but after installing it, I can't find how to use (the instructions are poor...
by seanspotatobusiness
Fri Aug 24, 2018 4:41 pm
Forum: Beginners
Topic: Auto-hide taskbar: taskbar is staying underneath full-screen windows so I can't see/use it
Replies: 11
Views: 2128

Re: Auto-hide taskbar: taskbar is staying underneath full-screen windows so I can't see/use it

Maximised windows don't cover the panel because you have 'minimise panel' activated... Switch it off and your problem is solved That doesn't solve the problem though. Windows has the same feature called "auto-hide taskbar". It lets you get that strip of screen space for all your windows and when yo...
by seanspotatobusiness
Fri Aug 24, 2018 4:41 pm
Forum: Beginners
Topic: Auto-hide taskbar: taskbar is staying underneath full-screen windows so I can't see/use it
Replies: 11
Views: 2128

Re: Auto-hide taskbar: taskbar is staying underneath full-screen windows so I can't see/use it

Maximised windows don't cover the panel because you have 'minimise panel' activated... Switch it off and your problem is solved That doesn't solve the problem though. Windows has the same feature called "auto-hide taskbar". It lets you get that strip of screen space for all your windows and when yo...
by seanspotatobusiness
Fri Aug 24, 2018 4:06 pm
Forum: Beginners
Topic: Auto-hide taskbar: taskbar is staying underneath full-screen windows so I can't see/use it
Replies: 11
Views: 2128

Re: Auto-hide taskbar: taskbar is staying underneath full-screen windows so I can't see/use it

DirkS wrote:
Fri Aug 24, 2018 3:59 pm
Check the panel settings (right click on the panel), tab advanced.
'Reserve space, and not covered by maximised windows' should be enabled to keep the panel clear.
Thanks. Unfortunately, that cannot be the problem because it's correctly set:

Image
by seanspotatobusiness
Fri Aug 24, 2018 4:02 pm
Forum: Beginners
Topic: Find out which program is hogging my microSD
Replies: 3
Views: 413

Re: Find out which program is hogging my microSD

Yes, it seems like one of my processes is leaking memory. I'll report the bug. Thanks very much.

Is there any way to find out where a program is reading/writing to, in case it's not the swap?
by seanspotatobusiness
Fri Aug 24, 2018 2:51 pm
Forum: Beginners
Topic: Visual disk usage analyser like WinDirStat or QDirStat?
Replies: 1
Views: 452

Visual disk usage analyser like WinDirStat or QDirStat?

Is there a tool like WinDirStat that shows how the disk(s) are being used and is easy to install on Raspbian?
by seanspotatobusiness
Fri Aug 24, 2018 2:39 pm
Forum: Beginners
Topic: Auto-hide taskbar: taskbar is staying underneath full-screen windows so I can't see/use it
Replies: 11
Views: 2128

Re: Auto-hide taskbar: taskbar is staying underneath full-screen windows so I can't see/use it

This screenshot illustrates the problem. If the browser window was maximised, you wouldn't see the taskbar at all but not maximising the windows defeats the whole point of using an auto-hiding taskbar. Image
by seanspotatobusiness
Thu Aug 23, 2018 10:14 pm
Forum: Beginners
Topic: Find out which program is hogging my microSD
Replies: 3
Views: 413

Find out which program is hogging my microSD

My Pi 3 is functioning very slowly and I'd like to find out what is responsible. I notice that while CPU utilisation is <20%, the microSD activity light is on constantly so that must by why but I'd like to know what program is doing this.

Go to advanced search