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by W. H. Heydt
Mon Dec 16, 2019 6:32 am
Forum: General discussion
Topic: PLEASE HELP!! /// SEEKING PROGRAMMING EXPERIENCE ADVICE!!
Replies: 33
Views: 772

Re: PLEASE HELP!! /// SEEKING PROGRAMMING EXPERIENCE ADVICE!!

Thanks everyone, for all the help so far! I have personally always been a big fan of learning from books, and I feel that works really well for me. One of my all time favourites is CODE by Charles Petzold. It’s simple, untangled explanations of how computer hardware works at it’s essence is (in my ...
by W. H. Heydt
Mon Dec 16, 2019 4:54 am
Forum: General discussion
Topic: Graph & timeline of Pi Sales
Replies: 93
Views: 29254

Re: Graph & timeline of Pi Sales

Gavinmc42 wrote:
Mon Dec 16, 2019 12:52 am
10Million a year?
Another 8 years is another 80Million?
A post from December last year said 23 million and it's now 30 million, so sales are up to 7 million per year.
by W. H. Heydt
Sun Dec 15, 2019 5:44 pm
Forum: General discussion
Topic: SD card or Micro SD card?
Replies: 16
Views: 377

Re: SD card or Micro SD card?

1) All recent models use micro SD. In fact, you'd be hard pressed to find any of the ones that use the full size card available for sale anywhere. And if you did, you might want to buy it and put it in a museum or in your trophy case. So, the question is pretty much moot. Anyone starting out now wi...
by W. H. Heydt
Sun Dec 15, 2019 4:38 am
Forum: General discussion
Topic: Portable Monitors for Raspberry Pi
Replies: 2
Views: 141

Re: Portable Monitors for Raspberry Pi

You might consider one of these...https://www.packedpixels.com/
by W. H. Heydt
Sat Dec 14, 2019 10:00 pm
Forum: General discussion
Topic: USB Cable for power to RPI4
Replies: 9
Views: 225

Re: USB Cable for power to RPI4

Since you're going to the GPIO pins (I won't ask why), it doesn't matter what cable you use, so long as the other end fits your PSU and has think enough wires to carry the required current (up to 3A).
by W. H. Heydt
Sat Dec 14, 2019 9:19 pm
Forum: General discussion
Topic: recovery from power failure
Replies: 9
Views: 264

Re: recovery from power failure

A modest UPS should take care of that. OK, do you have any specific idea of specs or actual models of suitable UPS? I don't know what 'modest' means in this context. This https://www.newegg.com/cyberpower-cp350slg-nema-5-15r/p/N82E16842102135?Description=ups&cm_re=ups-_-42-102-135-_-Product model i...
by W. H. Heydt
Sat Dec 14, 2019 6:12 pm
Forum: General discussion
Topic: recovery from power failure
Replies: 9
Views: 264

Re: recovery from power failure

The power went down for approx 3 mins (175 secs according to my logger). Everything else came back OK except the pis. Whatever fluctuations there were weren't enough to show anything different anywhere. (I suspect we have some dodgy switchgear somewhere in the neighbourhood that drops power briefly...
by W. H. Heydt
Sat Dec 14, 2019 12:31 am
Forum: General discussion
Topic: PLEASE HELP!! /// SEEKING PROGRAMMING EXPERIENCE ADVICE!!
Replies: 33
Views: 772

Re: PLEASE HELP!! /// SEEKING PROGRAMMING EXPERIENCE ADVICE!!

There are tons of books on learning to program. Books have the advantage that the won't go plowing ahead before you've got a grip on any given part. A source you may not have though of would be to look into your local junior/community college or adult education programs to see if they have beginning...
by W. H. Heydt
Sat Dec 14, 2019 12:25 am
Forum: General discussion
Topic: recovery from power failure
Replies: 9
Views: 264

Re: recovery from power failure

A major problem (from the standpoint of relatively sensitive electronics) with utility power outages is that the power frequently doesn't drop cleanly and doesn't come back cleanly. In both directions it will tend to bounce a few times due to random fluctuations and whatever other power loads are be...
by W. H. Heydt
Fri Dec 13, 2019 8:41 pm
Forum: Troubleshooting
Topic: Sudo instructions to insert a directory within /home
Replies: 13
Views: 251

Re: Sudo instructions to insert a directory within /home

What it all really comes down to is: You can't add a directory under a directory you don't own. Using root privileges bypasses that. That's what sudo is for. You're not going to be able to bypass using sudo, or some other means of working with root privileges. Again...this is for *your* protection a...
by W. H. Heydt
Fri Dec 13, 2019 8:38 pm
Forum: Troubleshooting
Topic: Sudo instructions to insert a directory within /home
Replies: 13
Views: 251

Re: Sudo instructions to insert a directory within /home

thagrol wrote:
Fri Dec 13, 2019 6:37 pm
You could do something like this:

Code: Select all

sudo mkdir /home/some_directory
sudo chmod a+rwx /home/some_driectory
A better choice for that second line would be:

Code: Select all

sudo chown <some_user_account> /home/<some_directory>
by W. H. Heydt
Fri Dec 13, 2019 4:45 pm
Forum: Troubleshooting
Topic: Sudo instructions to insert a directory within /home
Replies: 13
Views: 251

Re: Sudo instructions to insert a directory within /home

That requires root privileges...and it's a feature, not a bug. You can do it either with "sudo mkdir /home/<directoryname>" or "sudo su -" then "mkdir /home/<directoryname>". Or any other method of escalating privileges to root. The reason for need root privileges is that root owns /home and requiri...
by W. H. Heydt
Fri Dec 13, 2019 4:43 am
Forum: General discussion
Topic: crontab not working on pi zero
Replies: 10
Views: 248

Re: crontab not working on pi zero

mrjoli021 wrote:
Fri Dec 13, 2019 4:02 am
I got it working. I had to add the timezone to the crontab.

Code: Select all

TZ=America/New_York
thanks,
That's interesting. As asked above, what OS (and version) are you running? My "alarm clock" (Pi2Bv1.1 currently running Raspbian Stretch) doesn't have that problem.
by W. H. Heydt
Fri Dec 13, 2019 1:27 am
Forum: Advanced users
Topic: Raspberry Pi 4 ROM bootloader
Replies: 30
Views: 1158

Re: Raspberry Pi 4 ROM bootloader

trejan wrote:
Fri Dec 13, 2019 1:09 am
Don't know for the BCM2838 in the Pi 4. I expect it is the same though.
BCM2711. Likely the same as, for instance, the USB 2.0 interface is the same.
by W. H. Heydt
Fri Dec 13, 2019 12:39 am
Forum: Other programming languages
Topic: Google api in a raspberry pi
Replies: 8
Views: 188

Re: Google api in a raspberry pi

That did. But me being new to this environment didn't understand anything. All I could figure out is that the API commands for VS and PYTHON(raspbian) is different. But when I import it as a .exe file does it really matter in raspbian environment? In general, one would not expect a .exe file to run...
by W. H. Heydt
Fri Dec 13, 2019 12:23 am
Forum: Beginners
Topic: What kind of monitor can I use?
Replies: 8
Views: 220

Re: What kind of monitor can I use?

Just to show how wild it can get, I have Pis hooked up to an HDMI/USB KVM switch, where to video then goes through an HDMI to VGA converter to a VGA/PS/2 KVM switch and on the my 27" 1920x1080 Viewsonic VA2702w monitor. Works fine and I don't have to play with parameters or and such hassles. To do i...
by W. H. Heydt
Thu Dec 12, 2019 7:22 pm
Forum: General discussion
Topic: New Pi 4B as a laptop - questions plz
Replies: 10
Views: 316

Re: New Pi 4B as a laptop - questions plz

Also, any news on upgrade of USB on Raspberry Pi keyboard to USB 3.0 or 3.1 any time soon? There wouldn't be any point to doing that. USB 2.0 is far faster than anyone can type, even if you include mouse data. Also, there is an M.2 NVME HAT MADE FOR ROCK PI 4. Not by the RPT/RPF. Will Raspberry Pi ...
by W. H. Heydt
Thu Dec 12, 2019 7:16 pm
Forum: General discussion
Topic: crontab not working on pi zero
Replies: 10
Views: 248

Re: crontab not working on pi zero

I'm out of ideas. It's clearly running at the correct time...where it takes the time as UTC. So something is causing cron to use that, rather than local system time zone. Perhaps someone else will pop in with some better ideas.
by W. H. Heydt
Thu Dec 12, 2019 4:57 pm
Forum: General discussion
Topic: crontab not working on pi zero
Replies: 10
Views: 248

Re: crontab not working on pi zero

The 30 min is fine. I am concerned about the hour. It is supposed to run at 1AM and 5PM and it doesn't. It runs at noon and at 8PM why?? I use "crontab -e" to edit it. I am doing this as root so that permission won't be an issue. I know I shouldn't run this as root, but I am trying to figure out wh...
by W. H. Heydt
Thu Dec 12, 2019 4:39 pm
Forum: General discussion
Topic: crontab not working on pi zero
Replies: 10
Views: 248

Re: crontab not working on pi zero

The 30 minutes after the hour is because that's what you told it to do (the first parameter in the crontab line).

How did you add the line to crontab (i.e. which crontab)?
by W. H. Heydt
Thu Dec 12, 2019 4:24 pm
Forum: Beginners
Topic: Screen has green pixels and flashes
Replies: 2
Views: 64

Re: Screen has green pixels and flashes

Sounds like interference (i.e. noise) to me. Make sure you're using a shielded cable, try boosting the HDMI signal strength, look around for any source of electronic noise near by (e.g. microwave oven or PC) and move father from it.
by W. H. Heydt
Thu Dec 12, 2019 5:26 am
Forum: Advanced users
Topic: Raspberry Pi 4 ROM bootloader
Replies: 30
Views: 1158

Re: Raspberry Pi 4 ROM bootloader

OP is First time poster. It is like going into KFC for the first time and asking what are your 11 secret herbs and spices? My main interest in VideoCore is in turning a Pi 4B into a quite powerful, self-contained, standalone Arduino-style board. Bootloader, program loader, and user program all held...
by W. H. Heydt
Thu Dec 12, 2019 5:23 am
Forum: Advanced users
Topic: Raspberry Pi 4 ROM bootloader
Replies: 30
Views: 1158

Re: Raspberry Pi 4 ROM bootloader

OP is First time poster. It is like going into KFC for the first time and asking what are your 11 secret herbs and spices? My main interest in VideoCore is in turning a Pi 4B into a quite powerful, self-contained, standalone Arduino-style board. Bootloader, program loader, and user program all held...
by W. H. Heydt
Thu Dec 12, 2019 4:01 am
Forum: General discussion
Topic: SD-CARD size problem
Replies: 13
Views: 385

Re: SD-CARD size problem

"gparted" is a graphical file system editor. It can be used to expand, shrink, move, delete, create and format partitions. It won't actually do anything but look at a live (mounted) partition. You need to boot from a different device than the one you're going to be editing. You can install it by run...
by W. H. Heydt
Thu Dec 12, 2019 3:18 am
Forum: General discussion
Topic: SD-CARD size problem
Replies: 13
Views: 385

Re: SD-CARD size problem

Run df and post the results between "code" tags.

Also...you can't edit partitions when they're mounted. You should use a second card, install gparted, and then connect the card to be modified in a USB-to-SD holder. Gparted can be told to unmount it when needed.

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