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by davidcoton
Sat Jun 12, 2021 3:55 pm
Forum: General discussion
Topic: Is it possible to receive data from the USB-C port of the Raspberry Pi 4?
Replies: 9
Views: 208

Re: Is it possible to receive data from the USB-C port of the Raspberry Pi 4?

Something not quite right there, "dr_mode" can't be "host" for both modes.

Rather usefully, the readme says
Params: dr_mode Dual role mode: "host", "peripheral" or "otg"
without further explanation.
by davidcoton
Fri Jun 11, 2021 9:17 pm
Forum: Troubleshooting
Topic: Different boot menu on Kali
Replies: 3
Views: 105

Re: Different boot menu on Kali

Thanks for the reply! I tried Berryboot at first (on the SSD) but then I had issues with updating to the newer versions of Twister and Kali. I also noticed that any time I tried to run or install any tools on Kali there was a ton of issues because of it. Would there be issues with updating the diff...
by davidcoton
Fri Jun 11, 2021 5:17 pm
Forum: Troubleshooting
Topic: Different boot menu on Kali
Replies: 3
Views: 105

Re: Different boot menu on Kali

Consider Pinn with both OS on the SSD.
by davidcoton
Fri Jun 11, 2021 4:53 pm
Forum: Advanced users
Topic: What happens if the 5 V PSU input falls below the specification?
Replies: 14
Views: 397

Re: What happens if the 5 V PSU input falls below the specification?

The Pi0 (and indeed, all other current Pi up to Pi4*) has no built-in way to measure the supply voltage. It is pointless anyway to measure the 5V supply -- by the time that collapses, the battery is absolutely dead, and it's too late for a safe shutdown. This is because the DC-DC converter will main...
by davidcoton
Fri Jun 11, 2021 4:40 pm
Forum: General discussion
Topic: Porting old Pi3 distribution to pi4.
Replies: 27
Views: 709

Re: Porting old Pi3 distribution to pi4.

Just repeating the official documentation: you need a newer release is not helping. Of course the foundation cannot spend too much trouble maintaining the old releases of the OS. So instead of back-porting whatever was necessary to make buster work on pi4, they just say: not supported you're on you...
by davidcoton
Fri Jun 11, 2021 10:49 am
Forum: General discussion
Topic: Understanding multiple HATs compatibility
Replies: 8
Views: 166

Re: Understanding multiple HATs compatibility

Well, there are clearly conflicts there. UART (8&10), for certain, eeprom access (27&28) probably, I2C(2&3) possibly (but probably compatible).
by davidcoton
Fri Jun 11, 2021 10:42 am
Forum: General discussion
Topic: Simulation on Raspberry Pi
Replies: 6
Views: 283

Re: Simulation on Raspberry Pi

Are you a programmer? A student? What programming language are you comfortable with? What operating system do you have on your Pi? Is the program a script or compiled? What hardware and OS does it run on - Windows, Linux, etc? What does it do? What do you mean by "simulate"? And what mode...
by davidcoton
Fri Jun 11, 2021 9:18 am
Forum: Troubleshooting
Topic: Tv-out does not work with USB boot
Replies: 7
Views: 202

Re: Tv-out does not work with USB boot

Maybe the clock slow-down is sufficient to break the usb mass storage functionality? Or maybe it's the difference between "=on" and "=1", though I thought invalid lines in config.txt were ignored. And I have no idea why a commented line would prevent booting. I think there is mo...
by davidcoton
Thu Jun 10, 2021 9:17 am
Forum: General discussion
Topic: Powering LEDS with an external supply and controlling them with the Raspberry Pi
Replies: 11
Views: 409

Re: Powering LEDS with an external supply and controlling them with the Raspberry Pi

1/2 watt is not adequate as the design stands. Double the resistor values to 22R and 15R (nearest preferred values) if using 1/2 watt, the LEDs will be less bright, but the resistors should survive. If you have enough ½W resistors, you could make a 1W 11R resistor by joining two 22R ½W resistors to...
by davidcoton
Wed Jun 09, 2021 10:16 pm
Forum: General discussion
Topic: Powering LEDS with an external supply and controlling them with the Raspberry Pi
Replies: 11
Views: 409

Re: Powering LEDS with an external supply and controlling them with the Raspberry Pi

And the drawing....
PiLED.jpg
PiLED.jpg (228.11 KiB) Viewed 166 times
Hope one of the other regulars will check it before you use it ... of course I never (think I) make mistakes :o :shock: :? :lol: :roll:
by davidcoton
Wed Jun 09, 2021 9:27 pm
Forum: General discussion
Topic: Corporate identity Raspberry pi
Replies: 42
Views: 1457

Re: Corporate identity Raspberry pi

W. H. Heydt wrote:
Wed Jun 09, 2021 8:57 pm
the current tempest--and it can be debated whether or not it will fit in a teapot--is one of appending a suffix to an otherwise unobjectionable word that turns it into one that reads like a slur used against another group.
So we need a Wordgate Tea Urn to contain it?
by davidcoton
Wed Jun 09, 2021 9:23 pm
Forum: General discussion
Topic: Powering LEDS with an external supply and controlling them with the Raspberry Pi
Replies: 11
Views: 409

Re: Powering LEDS with an external supply and controlling them with the Raspberry Pi

thankfully I have a kit of resistors rated for 1/2 watts, 1/2 watt is not adequate as the design stands. Double the resistor values to 22R and 15R (nearest preferred values) if using 1/2 watt, the LEDs will be less bright, but the resistors should survive. Your kit may not have low enough values, a...
by davidcoton
Wed Jun 09, 2021 5:49 pm
Forum: General discussion
Topic: Powering LEDS with an external supply and controlling them with the Raspberry Pi
Replies: 11
Views: 409

Re: Powering LEDS with an external supply and controlling them with the Raspberry Pi

OK, so you want a current of 280-350mA per LED. So we will calculate a series current limiting resistor for a current of 300mA at a minimum forward voltage, just to be safe. Using a 5V supply: The Red LEDs have a minimum drop of 2V, leaving 3V across the series resistor. For 300mA, that means 10R (S...
by davidcoton
Wed Jun 09, 2021 4:30 pm
Forum: General discussion
Topic: Powering LEDS with an external supply and controlling them with the Raspberry Pi
Replies: 11
Views: 409

Re: Powering LEDS with an external supply and controlling them with the Raspberry Pi

Essentially I am switching them on and off, my code lets me switch colors and lets me flash them at certain rates, the LED diagram says that the test current was 500mA, but I think whatever milliamps the GPIO can output works as well since I managed to turn a few of them on without an external powe...
by davidcoton
Wed Jun 09, 2021 3:59 pm
Forum: General discussion
Topic: Powering LEDS with an external supply and controlling them with the Raspberry Pi
Replies: 11
Views: 409

Re: Powering LEDS with an external supply and controlling them with the Raspberry Pi

STOP. You will destroy you Pi like that. You MUST NOT try to control any load with a 5V supply directly from the Pi. There must be a transistor, FET, relay, or similar in between. Even at 3V3 the current capacity of each GPIO, and of all GPIOs together, is limited. What current does each LED (or gro...
by davidcoton
Tue Jun 08, 2021 9:09 pm
Forum: Beginners
Topic: 12 Node Cluster Power Supply
Replies: 6
Views: 153

Re: 12 Node Cluster Power Supply

Thanks for your reply. It was extremely helpful. At least now I know what to look for. Unfortunately I don’t know how to wire a 5V GPIO pin so I would have to research it. See here to identify the pins. You still need a suitable connector to deliver the current (depending on the circumstances, 1A3 ...
by davidcoton
Tue Jun 08, 2021 9:01 pm
Forum: Beginners
Topic: 12 Node Cluster Power Supply
Replies: 6
Views: 153

Re: 12 Node Cluster Power Supply

It's not quite that bad. A stressed Pi4B, without peripherals, shouldn't exceed 1A3 (see here ). So that's 16A (80W). Allow some for the fans and any other peripherals, if necessary, and a bit of headroom, 20A is plenty. On a Pi4, supplying power through the GPIO header is exactly the same as using ...
by davidcoton
Tue Jun 08, 2021 8:43 pm
Forum: General discussion
Topic: STICKY: Raspberry Pi OS (64 bit) beta test version feedback
Replies: 832
Views: 188976

Re: STICKY: Raspberry Pi OS (64 bit) beta test version feedback

Good evening , is it worth installing the 64bit version in my Pi4 8GB currently have the 32bit pi os installed would like to move over to the 64bit. Mainly use it at the moment for some retro gaming and hosting my websites im working on ect Or should i just wait til a much stable version is release...
by davidcoton
Tue Jun 08, 2021 1:05 pm
Forum: General discussion
Topic: I need help with a project that needs lots of IOs
Replies: 39
Views: 1045

Re: I need help with a project that needs lots of IOs

My assessment of this project is that there is nothing difficult (except spanning the wiring (barely electronics), bought-in hardware, and software), but that the wiring is on a non-trivial (irony flag!) scale. The hardest bit might be identifying the "best" I/O expansion board. The naïve...
by davidcoton
Tue Jun 08, 2021 11:24 am
Forum: General discussion
Topic: I need help with a project that needs lots of IOs
Replies: 39
Views: 1045

Re: I need help with a project that needs lots of IOs

So I think it would be best to start on some simpler projects without commercial pressure and take some courses. Maybe. In one job, I taught myself C, so I could write a program that parsed a lot of text (up to 5MB in one go) in order to manipulate the footmatter prior to publication. Quite a lot o...
by davidcoton
Tue Jun 08, 2021 8:58 am
Forum: General discussion
Topic: I need help with a project that needs lots of IOs
Replies: 39
Views: 1045

Re: I need help with a project that needs lots of IOs

I'd need some serious commercial justification to DIY it when there are proven systems like that exist. It will be a lot of work to come close to matching it. So would I. It just depends on the cost of a commercial product that does more than the OP thinks he needs. But don't underestimate the &quo...
by davidcoton
Tue Jun 08, 2021 8:46 am
Forum: General discussion
Topic: Pi Zero Boot from SSD
Replies: 35
Views: 1214

Re: Pi Zero Boot from SSD

GlowInTheDark wrote:
Tue Jun 08, 2021 5:14 am
I love the ginormous smiley. Beautiful!
:(
And, I hate ordinary smileys. Usenet figured out, oh, say, 3 decades ago, that smileys were for wannabees.
:o :shock: :? :roll:
by davidcoton
Mon Jun 07, 2021 9:31 pm
Forum: General discussion
Topic: Pi Zero Boot from SSD
Replies: 35
Views: 1214

Re: Pi Zero Boot from SSD

alexnh wrote:
Mon Jun 07, 2021 8:59 pm
Every day is a school day ...
:roll: Today's lesson is to stick to the Smilies provided on the forum -- others come out ginormous under the Rpi theme and make some users annoyed.
Unfortunately, your country doesn't need noyeds, only lerts.
by davidcoton
Mon Jun 07, 2021 9:26 pm
Forum: General discussion
Topic: I need help with a project that needs lots of IOs
Replies: 39
Views: 1045

Re: I need help with a project that needs lots of IOs

I'd need some serious commercial justification to DIY it when there are proven systems like that exist. It will be a lot of work to come close to matching it. So would I. It just depends on the cost of a commercial product that does more than the OP thinks he needs. But don't underestimate the &quo...
by davidcoton
Mon Jun 07, 2021 9:22 pm
Forum: General discussion
Topic: STICKY: Raspberry Pi OS (64 bit) beta test version feedback
Replies: 832
Views: 188976

Re: STICKY: Raspberry Pi OS (64 bit) beta test version feedback

Poor children would be disappointed. Why? If they are capable of assessing it and writing helpful beta test reports, then they can use it and report anything it fails to do as it should (given that some functionality is known to be incomplete). Especially if they have an application that should act...

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