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by dl324
Sat Jun 15, 2019 3:17 am
Forum: Troubleshooting
Topic: Using GPIO
Replies: 9
Views: 238

Re: Using GPIO

You're using different GPIO's. The first script is using Broadcom numbers and the second uses Pi numbering. Comment out the setmode command in the first script and they'll use the same GPIO.

You shouldn't be making resistance measurements with a DVM on a powered circuit.
by dl324
Fri Jun 14, 2019 3:49 pm
Forum: Beginners
Topic: Reboot raspberry pi and run a script after
Replies: 5
Views: 138

Re: Reboot raspberry pi and run a script after

Nathan1258 wrote:
Fri Jun 14, 2019 3:33 pm
Basically how do I continue running the script once the pi has rebooted again?
Can't be done. You can start the script automatically at reboot, but you can't have it resume. The current state can't be maintained across boots.
by dl324
Fri Jun 14, 2019 1:17 am
Forum: Troubleshooting
Topic: Failed boot after update/upgrade
Replies: 1
Views: 62

Re: Failed boot after update/upgrade

If it were me, I'd copy Raspian to a new SD card. Boot to it and mount your original SD card with a USB adapter and copy the important files to the new card. Then, before doing anything significant in the future, back up the image. Also make backups of your work whenever you do something you don't w...
by dl324
Thu Jun 13, 2019 6:19 pm
Forum: Beginners
Topic: HOOBS, NOOBS: Differences?
Replies: 4
Views: 173

Re: HOOBS, NOOBS & BOOBS: Differences?

So, it wouldn't be wrong for me to make an image backup of that uSD card for safety, and then to reformat it and using Etcher to put Raspbian on it? I would guess that this would give me pretty much the same thing as on my first RPi, which I got less than 2 weeks ago. If you like how you have your ...
by dl324
Thu Jun 13, 2019 2:53 pm
Forum: General discussion
Topic: CMOS Technology on BCM2837
Replies: 3
Views: 164

Re: CMOS Technology on BCM2837

Especially it's would be great to know what is the size of CMOS transistor (in nm). It's unlikely that they only used one transistor size. The smallest transistors will be in the memory array and they're typically smaller than any logic transistors because the array is very regular and they can opt...
by dl324
Thu Jun 13, 2019 3:37 am
Forum: Troubleshooting
Topic: Defective Pi Zero? No power
Replies: 3
Views: 113

Re: Defective Pi Zero? No power

Pi Zero W only has a green LED that indicates activity on the SD card.

Have you measured the 5V and 3.3V pins on the header, or holes if you didn't buy the version with headers installed?
by dl324
Thu Jun 13, 2019 2:10 am
Forum: General discussion
Topic: Create a desktop shortcut
Replies: 3
Views: 144

Re: Create a desktop shortcut

Is the file executable?

I just tried and you're going to be prompted whether you want to execute the file. That seems to be a feature.
by dl324
Wed Jun 12, 2019 1:29 pm
Forum: General discussion
Topic: Forgot my password.
Replies: 11
Views: 441

Re: Forgot my password.

Moomoo5 wrote:
Tue Jun 11, 2019 8:25 pm
I have so many files though.
I'd suggest you get in the habit of backing up work you want to save. I do it daily. I copy the tar files to my Windows PC that's also backed up daily.
by dl324
Sun Jun 09, 2019 9:20 pm
Forum: Troubleshooting
Topic: RasPi B+ Stopped working suddenly, won't boot back up
Replies: 8
Views: 231

Re: RasPi B+ Stopped working suddenly, won't boot back up

Jake.B wrote:
Sun Jun 09, 2019 4:53 am
The light still comes on so I guess something is going right?
If you're referring to the red LED, that's a 5V present indicator. There isn't an LED on 3.3V, you need to measure on the header.
by dl324
Sun Jun 09, 2019 2:26 pm
Forum: General discussion
Topic: How do I keep my Pi clean?
Replies: 16
Views: 503

Re: How do I keep my Pi clean?

DarkPlatinum wrote:
Sun Jun 09, 2019 10:21 am
How do I decrease the amount of dust going into the Pi? Is there some sort of air filter I can put on top of the fan?
Why bother with a filter? You probably have a lot of things gathering dust. Just dust them off if it builds up enough to bother you.
by dl324
Sun Jun 09, 2019 1:53 am
Forum: Troubleshooting
Topic: RasPi B+ Stopped working suddenly, won't boot back up
Replies: 8
Views: 231

Re: RasPi B+ Stopped working suddenly, won't boot back up

I was using Pin 1 as the 3.3V output, is this where I went wrong? If you shorted the 3.3V supply, it shouldn't damage the BCM2835 (you are talking about RPi B+, not 3B+, correct?). If the RPF bothered to put the part number for the voltage regulator on the schematic, I'd be inclined to look at the ...
by dl324
Thu Jun 06, 2019 1:57 pm
Forum: General discussion
Topic: light detector with photo transistor
Replies: 33
Views: 921

Re: light detector with photo transistor

It would be nice if anybody help me with making a circuit with it. This circuit will give you a LOW when light is above below the threshold you set with R3 is detected: EDIT: corrected polarity. photoTranComp.jpg If you want the opposite polarity, swap the comparator inputs. BTW, if you're not goin...
by dl324
Thu Jun 06, 2019 2:00 am
Forum: Beginners
Topic: Can not enable VNC server even if it seems to be, can be caused by TightVNC?by
Replies: 1
Views: 91

Re: Can not enable VNC server even if it seems to be, can be caused by TightVNC?by

If you want to try to revert to the default vncserver with Raspberry Stretch, try installing realvnc-vnc-server and realvnc-vnc-viewer. I contemplated installing tightvnc when I thought my Pi Zero vnc sessions were slow due to Real VNC server. When I saw that it seemed to want to remove the existing...
by dl324
Mon Jun 03, 2019 2:08 am
Forum: Troubleshooting
Topic: Can't connect via ssh
Replies: 1
Views: 38

Re: Can't connect via ssh

How is Pi connected to the network? WiFi, wired ethernet, USB?
by dl324
Sun Jun 02, 2019 11:10 pm
Forum: C/C++
Topic: How to control the GPIO pins using c++
Replies: 12
Views: 49344

Re: How to control the GPIO pins using c++

Could someone please explain to me (in the simplest way possible) how to control the GPIO pins using C++?? I don't care if it is not Wiring Pi, plus some simple example code (to light up a led?) would be greatly appreciated. If you don't need MHz speed, using the sysfs interface is the easiest. For...
by dl324
Fri May 31, 2019 2:31 pm
Forum: Off topic discussion
Topic: [solved - no changes will be made] Forum suggestions
Replies: 20
Views: 1286

Re: Forum suggestions

3. The OP name and date/time of the OP is already shown in the topics list. This is what I meant. On all subsequent posts in a thread, the person who started the thread is referred to as the Thread Starter (or Original Poster in other forums). That makes it easy to determine if you're responding to...
by dl324
Fri May 31, 2019 1:26 pm
Forum: Off topic discussion
Topic: [solved - no changes will be made] Forum suggestions
Replies: 20
Views: 1286

Re: [solved - no changes will be made] Forum suggestions

Multi-quote capability would have been nice too...
by dl324
Fri May 31, 2019 1:25 pm
Forum: Off topic discussion
Topic: [solved - no changes will be made] Forum suggestions
Replies: 20
Views: 1286

Re: Forum suggestions

bensimmo wrote:
Fri May 31, 2019 10:49 am
That's there on the default skin too (and in mobile view).
What is the "that" you're referring to?
by dl324
Fri May 31, 2019 1:23 pm
Forum: Off topic discussion
Topic: [solved - no changes will be made] Forum suggestions
Replies: 20
Views: 1286

Re: Forum suggestions

klricks wrote:
Fri May 31, 2019 5:17 am
Note I use Prosilver forum theme.
So do I. The other color schemes were hard on my eyes.
by dl324
Fri May 31, 2019 1:07 pm
Forum: Off topic discussion
Topic: [solved - no changes will be made] Forum suggestions
Replies: 20
Views: 1286

Re: Forum suggestions

Burngate wrote:
Fri May 31, 2019 9:31 am
AddFiles.jpg
I saw that you can drag files or use add files. What I wanted was the ability to do a partial screen grab and paste it into the text entry box. Now it's a multi-step process. Do a screen grab, save it as a file, drag the file to the text entry box, delete the file.
by dl324
Fri May 31, 2019 1:00 pm
Forum: Beginners
Topic: crontab always empty, but jobs are running
Replies: 14
Views: 388

Re: crontab always empty, but jobs are running

A few weeks later, I decided I wanted to run it every 15 minutes so I ran crontab -e again - but the job wasn't there. So I added it with the new frequency and now it runs every 15 minutes AND every hour. Are you saying that the job runs 5 times per hour? Post the crontab entry for the job in quest...
by dl324
Fri May 31, 2019 2:39 am
Forum: Off topic discussion
Topic: [solved - no changes will be made] Forum suggestions
Replies: 20
Views: 1286

[solved - no changes will be made] Forum suggestions

It would be nice 1. if a picture could be pasted from "the clipboard" into the text entry box. 2. if the forum software took care of scaling large images down to an appropriate size. 3. if the original poster was indicated in a thread. 4. to receive alerts for unread posts in subscribed threads, wit...
by dl324
Fri May 31, 2019 12:46 am
Forum: Automation, sensing and robotics
Topic: Help with Relays and GPIO
Replies: 4
Views: 241

Re: Help with Relays and GPIO

I'd have the GPIO drive an NPN transistor that switches the relay low side. Any common transistor in your locale would be sufficient (2N3904, BC547, etc). EDIT: Here's a schematic. relayNPN.jpg R1 should be sized to provide Ib=0.1Ic (0.05Ic if you use a high beta transistor like BC547). D1 should be...
by dl324
Thu May 30, 2019 3:19 pm
Forum: Troubleshooting
Topic: No access to dev/mem
Replies: 9
Views: 511

Re: No access to dev/mem

marius_bogdan96 wrote:
Thu May 30, 2019 6:04 am
How do I give root privileges?
Run the script using sudo.
by dl324
Wed May 29, 2019 3:00 pm
Forum: Troubleshooting
Topic: No access to dev/mem
Replies: 9
Views: 511

Re: No access to dev/mem

As the error message indicates, root privileges are required to access /dev/mem.

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