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by rpdom
Wed Oct 20, 2021 7:41 am
Forum: General discussion
Topic: Waiting fo root device after moving root to usb
Replies: 29
Views: 1395

Re: Waiting fo root device after moving root to usb

The switch message can be ignored. It is for information only. The microSD cards and slots do not have read-only (write protect) switches. Only full sized SD cards and adaptors have them. It looks like the root filesystem is not mounting. The bootloader is looking for a partition with the UUID of b3...
by rpdom
Tue Oct 19, 2021 7:59 pm
Forum: General discussion
Topic: Compile failed
Replies: 2
Views: 153

Re: Compile failed

I suggest asking acconeer. We can't see the code, so don't know what may be wrong with it.

Have you got a link to this code source?
by rpdom
Tue Oct 19, 2021 7:55 pm
Forum: Beginners
Topic: control 54 Relays
Replies: 10
Views: 312

Re: control 54 Relays

An alternative method, not sure how practical it is, 9 rotary switches driven by stepper motors or servos. Each switch connects to one pin on the valve and has 6 different positions. Thus allowing you to connect any pin to any of the voltages. One issue I can think of is that the switch would have t...
by rpdom
Tue Oct 19, 2021 7:41 pm
Forum: General discussion
Topic: Two-way data transfer between Pi's over a very long cable
Replies: 53
Views: 2292

Re: Two-way data transfer between Pi's over a very long cable

AnneRanch wrote:
Tue Oct 19, 2021 7:14 pm
Take a look at "cable adapters" - I am not sure there is "BNC to CATx " but one never knows.
There used to be, back in the old days, but they required external power and were slow (2Mb/s).
by rpdom
Tue Oct 19, 2021 2:24 pm
Forum: Troubleshooting
Topic: Raspi 4 - can utilise full SD space
Replies: 3
Views: 183

Re: Raspi 4 - can utilise full SD space

I did some reading and heard that anything over 32gb generally needs to be formatted in ExFat in order for Raspi to utilise the full space. I What you read was wrong. RaspiOS uses ext4, not exFAT and you don't need to preformat the card prior to installing an OS image. (Installing NOOBS or PINN req...
by rpdom
Tue Oct 19, 2021 12:21 pm
Forum: Troubleshooting
Topic: Raspberry 4 video sometimes goes off for a seconds
Replies: 7
Views: 255

Re: Raspberry 4 video sometimes goes off for a seconds

kerry_s wrote:
Tue Oct 19, 2021 11:59 am
it doesn't matter how many gb you have, the system GPU can only see/use 1024gb
FTFY

The ARM CPUs can see and use all of the memory*

*In 32-bit mode applications can only access up to 3GB each.
by rpdom
Tue Oct 19, 2021 10:32 am
Forum: Networking and servers
Topic: Looking for advice on web project.
Replies: 6
Views: 303

Re: Looking for advice on web project.

I was wondering if MySQL is still the correct choice for a server or should I be looking for the other database server I recall some news a while back and people were switching to something else MariaDB maybe? I've always suck with MySQL however if something else offers better performance on a Pi t...
by rpdom
Tue Oct 19, 2021 9:10 am
Forum: Troubleshooting
Topic: You don't have enough free space.
Replies: 5
Views: 214

Re: You don't have enough free space.

How much space have you got?

Use "df -h" to find out.
by rpdom
Tue Oct 19, 2021 8:23 am
Forum: General discussion
Topic: Raspberry pi zero WH and Huawei Stick
Replies: 4
Views: 197

Re: Raspberry pi zero WH and Huawei Stick

gordon77 wrote:
Tue Oct 19, 2021 8:14 am
You could try turning the usb power off

viewtopic.php?t=301217
That won't work on a Pi Zero. The USB power is hard wired to the 5V rail.
by rpdom
Tue Oct 19, 2021 8:21 am
Forum: Official Foundation Display
Topic: Raspberry Pi Official 7 Inch Touch Screen compatibility
Replies: 1
Views: 135

Re: Raspberry Pi Official 7 Inch Touch Screen compatibility

The Official display should work with the older Raspberry Pi A and B. It just uses a couple of extra cables to connect to the i2c GPIO pins. In later models the i2c used by the display was routed directly to the display connector. The only Pis that the screen isn't compatible with (so far) are the P...
by rpdom
Tue Oct 19, 2021 7:02 am
Forum: Beginners
Topic: help with sh bash script
Replies: 27
Views: 535

Re: help with sh bash script

That will work, but it will display the output from the grep which is probably not wanted.
To get rid of that try this line

Code: Select all

ip a show wwan0 | grep -q "UNKNOWN"
The -q option on grep means it won't show the output, but will still set the status.
by rpdom
Mon Oct 18, 2021 6:38 pm
Forum: Off topic discussion
Topic: Price increase by +50%?
Replies: 15
Views: 614

Re: Price increase by +50%?

Does anyone know a Seller who offer then for a good price? That depends on where in the world you are. Sellers on Ali Express and similar sites can charge what they like. Look on the Raspberry Pi website https://www.raspberrypi.com/products/raspberry-pi-4-model-b/ and click Buy Now to find an offic...
by rpdom
Mon Oct 18, 2021 5:07 pm
Forum: Beginners
Topic: To which GPIO is the fan connected? (BOARD vs GPIO numbering schemes)
Replies: 5
Views: 193

Re: To which GPIO is the fan connected? (BOARD vs GPIO numbering schemes)

Pin 4 and 6 are not GPIO pins. They are power pins. They can not be controlled.
by rpdom
Mon Oct 18, 2021 1:15 pm
Forum: Troubleshooting
Topic: Installing & running Go
Replies: 10
Views: 408

Re: Installing & running Go

hippy wrote:
Mon Oct 18, 2021 12:41 pm
Not the cutting-edge version but was good enough for what I was doing.
Bullseye, when it is officially released, will have golang 1.15 (2:1.15~1)
by rpdom
Mon Oct 18, 2021 10:57 am
Forum: Beginners
Topic: Newbie help - Damaged Model 1 B rev2
Replies: 10
Views: 380

Re: Newbie help - Damaged Model 1 B rev2

I do have a 1B Rev 2 I'm not using. That would be one alternative. Otherwise, you could try just upgrading the firmware/bootloader/kernel and kernel modules on the old card to support a newer model. It's not the best solution, but it works. I did that yesterday to upgrade a Pi 2B running Wheezy to a...
by rpdom
Mon Oct 18, 2021 8:03 am
Forum: General discussion
Topic: Dupont cables connection problem
Replies: 14
Views: 474

Re: Dupont cables connection problem

cleverca22 wrote:
Mon Oct 18, 2021 7:48 am
i suspect that those extra 40 wires, are shorted together, along with every pin on an ide connector that is ground
but those pins being shorted together on a pi, leads to problems....
Exactly this. A number of the pins are shorted together inside the plug and will cause gpio failure.
by rpdom
Mon Oct 18, 2021 7:41 am
Forum: HATs and other add-ons
Topic: Does Anyone Know of Large Character LCDs?
Replies: 24
Views: 705

Re: Does Anyone Know of Large Character LCDs?

You can power the 16x2, 20x4 LCDs from the Pi5. Have you got some insider knowledge? What are the specs of your Pi5? :lol: But yes, the HD44780 compatibles are usually easy to drive from a Pi, whether via an i2c backpack, or directly in 4-bit mode using 6 gpios. That was one of my first Bare Metal ...
by rpdom
Sun Oct 17, 2021 3:31 pm
Forum: HATs and other add-ons
Topic: Does Anyone Know of Large Character LCDs?
Replies: 24
Views: 705

Re: Does Anyone Know of Large Character LCDs?

The usual displays use the HD44780 or clones/compatible controllers and usually go from 8x1 to 20x4, although I think they support up to 32x4. If you want more lines and characters or larger characters then you'd be better off using a full graphics display panel. Anything else is going to be special...
by rpdom
Sun Oct 17, 2021 3:22 pm
Forum: Networking and servers
Topic: Raspberry Pi 3 B+ webserver project
Replies: 1
Views: 192

Re: Raspberry Pi 3 B+ webserver project

You're going to have to give us a bit more information than "doesn't work".

What doesn't work?

What errors do you get, if any, in the browser and in your webserver logs?

What software is being used for your webserver? (Apache/Nginx, PHP, Javascript etc)
by rpdom
Sat Oct 16, 2021 3:46 pm
Forum: General discussion
Topic: Raspberry pi zero v1.3 ipmi (piKVM)
Replies: 8
Views: 373

Re: Raspberry pi zero v1.3 ipmi (piKVM)

I am assuming that the built-in WiFi on the Zero W will be used to access it remotely. I can't see how it could work without that. The sole microUSB on the Zero is used to provide the keyboard/mouse emulator.
by rpdom
Fri Oct 15, 2021 4:14 pm
Forum: Networking and servers
Topic: Can not use "apt update", errors out
Replies: 4
Views: 182

Re: Can not use "apt update", errors out

Looking at your error messages, I can say three things: 1. DNS lookup is working for both IPv4 and IPv6. That means your Pi can access a working DNS server. 2. IPv6 is either unavailable, or is not routed correctly - "Network is unreachable". Not all ISPs provide IPv6 yet. 3. IPv4 is being...
by rpdom
Fri Oct 15, 2021 4:01 pm
Forum: Troubleshooting
Topic: Issue with SD Card Formatter
Replies: 9
Views: 337

Re: Issue with SD Card Formatter

I can only think that the RaspberryPi site pointed me there. I doubt that any current instructions on the Raspberry Pi site would point you at the NOOBS area on github. NOOBS has been effectively dead for a year or two now. If you can find a link from the site, post it here, or preferably use the g...
by rpdom
Thu Oct 14, 2021 5:14 pm
Forum: General discussion
Topic: how to best erase data on a big usb drive?
Replies: 9
Views: 362

Re: how to best erase data on a big usb drive?

Bosse_B wrote:
Thu Oct 14, 2021 4:28 pm
Would rm -r be a slow function given the size of the data on the disk?
rm will just parse the directory structure, unlinking all the allocated sectors and removing the filename entries. It doesn't overwrite the data, just marks it as free space. It shouldn't take long at all.
by rpdom
Thu Oct 14, 2021 4:17 pm
Forum: General discussion
Topic: how to best erase data on a big usb drive?
Replies: 9
Views: 362

Re: how to best erase data on a big usb drive?

Unmount the filesystem and just create a new ext4fs on there. You can do that from the command line use parted or gparted from the GUI (launched via a terminal).

rm -r would also work. It won't fully wipe the data, but will delete the filenames and make all the space available again.
by rpdom
Thu Oct 14, 2021 4:12 pm
Forum: General
Topic: Is the pico able to share the whole ram between the cores?
Replies: 5
Views: 350

Re: Is the pico able to share the whole ram between the cores?

To stray a little off topic - the Elliott 803 (look it up) at the National Computer Museum is now sporting a Raspberry Pico to mirror its entire RAM store. it checks new memory reads against the last write in real time to pinpoint memory errors on this venerable machine. There is a write-up here (s...

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