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by rpdom
Thu Jul 29, 2021 6:06 am
Forum: Python
Topic: Before I build, scoreboard questions.
Replies: 2
Views: 60

Re: Before I build, scoreboard questions.

Yes, that is possible. You can mix different types of WS2812B LEDs, but it might be easier to driver them using two separate channels. The Pi Zero doesn't have an analogue audio output, but it is possible to add a circuit with a small amp to do that for you. Or go for something like a Pi 3A+ - that ...
by rpdom
Wed Jul 28, 2021 2:12 pm
Forum: Troubleshooting
Topic: My Raspberry Pi 4 broke for no apparent reason - and was fixed in a very counterintuitive way!
Replies: 6
Views: 281

Re: My Raspberry Pi 4 broke for no apparent reason - and was fixed in a very counterintuitive way!

I tried shorting 3.3V to ground. The green LED blinked again, and this time I saw the Pi come to life!!! Somewhere you have something leaking voltage onto the 3.3V line. The MXL PMIC chip will not supply power to the Pi if it detects there is already voltage on the 3.3V line. By briefly shorting th...
by rpdom
Wed Jul 28, 2021 10:09 am
Forum: General discussion
Topic: How do you upload an image to this site?
Replies: 2
Views: 121

Re: How do you upload an image to this site?

Milliways wrote:
Wed Jul 28, 2021 9:41 am
How do you upload an image to this site?

There are [img] tags but apparently to way to upload.
Use the Attachments button, then you can upload an image file of up to 256KB. Then select the "show inline" option to embed the image with the correct tags.
by rpdom
Wed Jul 28, 2021 8:49 am
Forum: Beginners
Topic: LEDs?
Replies: 20
Views: 437

Re: LEDs?

The amount of power those LEDs will take shouldn't be enough to cause any problems. You'll still have 1200mA total available for the USB ports.
by rpdom
Wed Jul 28, 2021 8:22 am
Forum: Beginners
Topic: LEDs?
Replies: 20
Views: 437

Re: LEDs?

I can help with a diagram. I believe this is what is required.
LEDs.png
LEDs.png (5.45 KiB) Viewed 178 times
by rpdom
Tue Jul 27, 2021 7:12 pm
Forum: Beginners
Topic: update node.js problem
Replies: 12
Views: 322

Re: update node.js problem

mustafasei wrote:
Tue Jul 27, 2021 7:08 pm
sed -i 5,18d /etc/apt/sources.list
sed: couldn't open temporary file /etc/apt/sedhrErG9: Permission denied
Sorry, my fault. I forgot to say you need to put sudo in front of the sed command. I have corrected my previous post.
by rpdom
Tue Jul 27, 2021 6:40 pm
Forum: Beginners
Topic: update node.js problem
Replies: 12
Views: 322

Re: update node.js problem

If you type sudo nano /etc/apt/sources.list There are a few ways to do this. the most common is to use sudo nano /etc/apt/sources.list to let you edit the file, delete the lines you don't need, and the save the file by pressing Ctrl-o to "Write Out", then Ctrl-x to "Exit) as shown at ...
by rpdom
Tue Jul 27, 2021 3:38 pm
Forum: Beginners
Topic: update node.js problem
Replies: 12
Views: 322

Re: update node.js problem

below is the list : cat /etc/apt/sources.list deb http://mirrordirector.raspbian.org/raspbian/ jessie main contrib non-free rpi # Uncomment line below then 'apt-get update' to enable 'apt-get source' #deb-src http://archive.raspbian.org/raspbian/ jessie main contrib non-free rpi deb http://feeds.la...
by rpdom
Mon Jul 26, 2021 12:11 pm
Forum: Beginners
Topic: update node.js problem
Replies: 12
Views: 322

Re: update node.js problem

Can you please advise about that Not unless you show us what you have in that file. This is what I have in my default file: pi@raspberrypi:~ $ cat /etc/apt/sources.list deb http://deb.debian.org/debian buster main contrib non-free deb http://deb.debian.org/debian-security/ buster/updates main contr...
by rpdom
Sun Jul 25, 2021 5:54 pm
Forum: Troubleshooting
Topic: No ping, no ssh, no http; wired; headless
Replies: 23
Views: 490

Re: No ping, no ssh, no http; wired; headless

I noticed a difference between the output and the "cmdline.txt" entry. output: 1dda3fcb-01 cmdline.txt: root=PARTUUID=1dda3fcb-02 That is correct. The "-01" partition is the boot partition and will be mounted as /boot. The "-02" partition is the root partition and will...
by rpdom
Sun Jul 25, 2021 6:09 am
Forum: General discussion
Topic: HDMI dongle to Laptop ---keyboard???
Replies: 4
Views: 175

Re: HDMI dongle to Laptop ---keyboard???

Connect the two with a network cable and use VNC to remotely access the Pi desktop on the laptop.

(aBUGS beat me to it, but I'll leave this here for the link to the VNC instructions)
by rpdom
Fri Jul 23, 2021 5:12 pm
Forum: General discussion
Topic: SSH connection refused ?
Replies: 3
Views: 134

Re: SSH connection refused ?

I did ifconfig qe@qe-desktop:~$ ifconfig enp3s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 10.0.1.143 netmask 255.255.255.0 broadcast 10.0.1.255 This is showing the IP address of the computer your are using. Not the Pi. Can you connect to your Router/DHCP server and get a list of the...
by rpdom
Fri Jul 23, 2021 3:27 pm
Forum: General discussion
Topic: Advantages/Disadvantages of SDcards vs USB key
Replies: 13
Views: 799

Re: Advantages/Disadvantages of SDcards vs USB key

I thought that the swap was activated/disabled in the fstab file The default fstab says # a swapfile is not a swap partition, no line here # use dphys-swapfile swap[on|off] for that which means that a swap partition would be handled by fstab, but the swap file isn't. It is handled by dphys-swapfile...
by rpdom
Fri Jul 23, 2021 12:38 pm
Forum: Beginners
Topic: Wireless keyboard and mouse
Replies: 10
Views: 232

Re: Wireless keyboard and mouse

AFAIK, some Logitech wireless keyboards are not Bluetooth, and their "Unifying" receiver may need to be paired with the keyboard. I'm not sure if this can be done outside a Mac or Windows environment, so check before you commit if you're going with one of those. I have used a mouse with a...
by rpdom
Fri Jul 23, 2021 6:08 am
Forum: Beginners
Topic: Connecting a Pi to a PC - continued
Replies: 13
Views: 646

Re: Connecting a Pi to a PC - continued

The config file is /etc/dhcpcd.conf, not /etc/dhcpcd/config
by rpdom
Fri Jul 23, 2021 6:03 am
Forum: Advanced users
Topic: dual monitor; use each screen to display 1 output each
Replies: 4
Views: 231

Re: dual monitor; use each screen to display 1 output each

Jupiter? Which platform do you work with? It's not a Raspbian OS, isn't it? Make sure to update/upgrade as it's for sure not the latest kernel "jupiter" is the hostname. Not all Raspberry Pi systems are called "raspberrypi" ;) "5.10.17-v7l+ #1403" looks like a standard...
by rpdom
Thu Jul 22, 2021 12:34 pm
Forum: Advanced users
Topic: Rearranging partitions on SD Card
Replies: 5
Views: 270

Re: Rearranging partitions on SD Card

You specify the root partition in cmdline.txt
Make sure you also update the /etc/fstab file on the system, but I think it will boot even if that has the wrong rootfs.
by rpdom
Thu Jul 22, 2021 12:04 pm
Forum: Networking and servers
Topic: What are low-cost alternatives to SATA-USB adapters ?
Replies: 5
Views: 299

Re: What are low-cost alternatives to SATA-USB adapters ?

is that really SATA? looks like PATA to me... It's both. I have a similar adaptor. It has a 3.5" PATA interface on one side, a 2.5" PATA with power on the other and a SATA data socket on the back. Mine have lasted many years - I got my first one before the Pi came out and still use it occ...
by rpdom
Thu Jul 22, 2021 5:04 am
Forum: Python
Topic: python coding for voltage relays
Replies: 32
Views: 867

Re: python coding for voltage relays

I had to change if value >= 13.300 and value =< 16.300 to if value >= 13.300 and value <= 16.300 And elif Value to elif value It works... Sir you are a champion and thankyou so much I am starting to get my head around it. There is one small problem left- Every time it cycles through the relay is on...
by rpdom
Wed Jul 21, 2021 2:37 pm
Forum: Networking and servers
Topic: Trying to run Web Server with nginx!
Replies: 10
Views: 362

Re: Trying to run Web Server with nginx!

Ignore Dougie, he hasn't been following the thread or the tutorial. ;) Yes, the "Welcome to NGINX" is what you will get with that page, but if you make the changes I showed, ie. rip out part of it and replace with that "phpinfo" line, you will still get that header and then the l...
by rpdom
Wed Jul 21, 2021 10:01 am
Forum: Raspberry Pi OS
Topic: Inconsistent behavior creating disk images from dd
Replies: 12
Views: 416

Re: Inconsistent behavior creating disk images from dd

swampdog wrote:
Wed Jul 21, 2021 9:48 am
doh! I must have had rsync in my head when I wrote that. Dropper a clanger there.
Yep, rsync would do that. I usually use the --one-file-system or -x option when using rsync to prevent that happening.
by rpdom
Wed Jul 21, 2021 9:41 am
Forum: General
Topic: Recommended Power Supply for Pico
Replies: 11
Views: 304

Re: Recommended Power Supply for Pico

dbrion06 wrote:
Wed Jul 21, 2021 9:36 am
You are betting OP is using WS2812B. Where is it written?
It is quite likely. WS2812B are the most commonly available versions around. OP may be using WS2812C, but it is quite unlikely.

I agree that this is more likely to be an issue with available current though.
by rpdom
Wed Jul 21, 2021 9:20 am
Forum: Raspberry Pi OS
Topic: Inconsistent behavior creating disk images from dd
Replies: 12
Views: 416

Re: Inconsistent behavior creating disk images from dd

As for the 'dd' oddity, not only does it attempt to backup/restore transient items (like /proc device nodes, sockets) dd will not attempt to backup the contents of /proc (or /dev, /sys, /run etc) because they are virtual and do not exist on the card. Only the mountpoints for those file systems exist.
by rpdom
Wed Jul 21, 2021 9:01 am
Forum: General
Topic: Recommended Power Supply for Pico
Replies: 11
Views: 304

Re: Recommended Power Supply for Pico

According to https://randomnerdtutorials.com/esp32-s ... ensor-pcb/ neopixels can be fed with 5volts and controlled by an ESP32 (3v device). This is consistent with https://cdn.sparkfun.com/assets/4/c/8/a ... asheet.pdf, page 3, Electrical characteristics Din High can be between 2.7volts and Vsuppl...

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