Go to advanced search

by Burngate
Mon Jan 15, 2018 6:26 pm
Forum: Beginners
Topic: Internal pull up/down function explanation
Replies: 11
Views: 175

Re: Internal pull up/down function explanation

davidcoton wrote:
Mon Jan 15, 2018 2:13 pm
In the interests of nit-picking and accuracy of the physics:
Where would we be without nit-pickers? (probably still living in caves, scratching furiously, and watching the bonobos picking nits off each other)
And, yes, you're right and I'm wrong. Yet again. Sorry, and thanks.
by Burngate
Mon Jan 15, 2018 6:18 pm
Forum: General discussion
Topic: Eben Upton on BBC Radio 4 "The Life Scientific"
Replies: 5
Views: 237

Re: Eben Upton on BBC Radio 4 "The Life Scientific"

Irritating - my recorder won't record radio channels!
by Burngate
Mon Jan 15, 2018 6:04 pm
Forum: Other projects
Topic: PI DCF77 simulator
Replies: 7
Views: 104

Re: PI DCF77 simulator

How accurate does your equipment require the signal to be? Are you wanting your signal to be correct to within one cycle (~13μs for 77.5kHz) or just to the nearest second? Does the equipment just use the AM part of the signal, or does it want the phase-modulated part? I assume it can tolerate the wo...
by Burngate
Mon Jan 15, 2018 5:32 pm
Forum: Graphics, sound and multimedia
Topic: Giant video wall for music video using 30 Raspberry Pis
Replies: 2
Views: 66

Re: Giant video wall for music video using 30 Raspberry Pis

I counted 24 screens; assuming one Pi per screen, what were the other six doing?
Being CRTs, were they fed PAL, or HDMI? The picture didn't stay still enough to assess their quality!
by Burngate
Mon Jan 15, 2018 12:18 pm
Forum: Beginners
Topic: Internal pull up/down function explanation
Replies: 11
Views: 175

Re: Internal pull up/down function explanation

I'm not trying to ask how the principle of the up/down circuits work, I think I have a good understanding of that. ... Does this mean that the .PUD_UP is supplying voltage to the button waiting to be grounded and the .PUD_DOWN is acting as ground waiting to recieve voltage/current from the 3.3v rai...
by Burngate
Sat Jan 13, 2018 7:09 pm
Forum: Advanced users
Topic: Zero W exceeds USB spec for input capacitance?
Replies: 9
Views: 330

Re: Zero W exceeds USB spec for input capacitance?

The PDF linked to in the first post is called "Powering electronics from the USB port". It refers to the 5v power from a host, and what the host can expect from a peripheral connected to it.

It was written by someone at Texas Instruments, who I would assume knows what (s)he's talking about.
by Burngate
Sat Jan 13, 2018 6:59 pm
Forum: General discussion
Topic: When will Raspberry Foundation admit that the Pi destroys your SD cards?
Replies: 42
Views: 1454

Re: When will Raspberry Foundation admit that the Pi destroys your SD cards?

Okay, I had a few moments to relax, and allow me to apologize first. I was quite pissed off, ... Sorry, my frustration got the upper hand here... :oops: Would it be worth while changing the title of this thread ... maybe to something like ... "My Pi has destroyed umpteen SD cards, and I'd like to k...
by Burngate
Sat Jan 13, 2018 11:32 am
Forum: Advanced users
Topic: Zero W exceeds USB spec for input capacitance?
Replies: 9
Views: 330

Re: Zero W exceeds USB spec for input capacitance?

I'm guessing the explanation is that a Pi isn't a USB device - it uses a micro-USB connector for power because it's convenient, but doesn't have to adhere to the USB spec. because of that. A USB host should be designed to be able to continue working when a device is connected that adheres to the spe...
by Burngate
Sat Jan 13, 2018 9:56 am
Forum: General discussion
Topic: entertainment
Replies: 5
Views: 207

Re: entertainment

I enjoyed school. Apart from French. And German. And History, Geography, Gym, Sports, Music, English, ... Though mainly I enjoyed it because, although it was a boys' school, the other half of the building was a girls' school ... After GCE O-level, I was called into the head-master's office. "What do...
by Burngate
Fri Jan 12, 2018 6:28 pm
Forum: Troubleshooting
Topic: Can't get GPIO (or 5V pin) functioning [solved]
Replies: 12
Views: 232

Re: Can't get GPIO (or 5V pin) functioning

Just in case you've got it twisted round, it's worth noting that pin 1 (3v3) has a square rather than round solder pad.
by Burngate
Tue Jan 09, 2018 11:05 am
Forum: Troubleshooting
Topic: Raspberry Pi 3 rainbow screen with lightening bolt
Replies: 11
Views: 308

Re: Raspberry Pi 3 rainbow screen with lightening bolt

Looks like the 3.3 volts regulator is faulty or its load is drawing excessive current. Could this happen even when PP8 is at 3.37V? (I am following https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=89522) If PP8 is at 3.3v then the regulator probably isn't faulty. PP10 isn't a reliable test p...
by Burngate
Tue Jan 09, 2018 10:07 am
Forum: Graphics, sound and multimedia
Topic: Controlling Many Individual Lights
Replies: 1
Views: 72

Re: Controlling Many Individual Lights

I'd be Googling Addressable LED strings. They consist of LEDs (often red, green and blue together in a single block) mounted on top of a control chip. Each has a serial data input pin and serial data output pin, with each one taking its own data and passing the rest onwards. So you only need a coupl...
by Burngate
Mon Jan 08, 2018 6:50 pm
Forum: Troubleshooting
Topic: Pi detecting activity - resistor needed?
Replies: 9
Views: 227

Re: Pi detecting activity - resistor needed?

So again, my original problem of it firing when the HVAC kicks on is still there, and my sensor seems to read several "opened" settings as it opens. I should note that the wires for the sensor run through a very narrow area in my gate post that shares space with the hydraulic arm power cable that o...
by Burngate
Mon Jan 08, 2018 6:24 pm
Forum: Troubleshooting
Topic: Raspberry Pi 3 rainbow screen with lightening bolt
Replies: 11
Views: 308

Re: Raspberry Pi 3 rainbow screen with lightening bolt

... The PWR LED is on constantly. ... Voltage at all the test points are within tolerance, with the exception of the PP10, which reads 1.8V (brownout) instead of 3.3V. If the Lightning bolt is displayed, the red PWR LED should be off. If the red LED is on, there should be no lightning bolt. So I'm ...
by Burngate
Mon Jan 08, 2018 11:31 am
Forum: Raspbian
Topic: Raspberry Pi {stretch} tuns off randomly.
Replies: 13
Views: 566

Re: Raspberry Pi {stretch} tuns off randomly.

Several things I would be asking. What is the time-scale - is it once a week, once a day, after five minutes, ... ? What software are you using? Is it plain unadorned Raspian? (I would assume you have installed some extra software, otherwise they won't be doing much, but I'm often wrong ...) Are the...
by Burngate
Mon Jan 08, 2018 10:49 am
Forum: Troubleshooting
Topic: Pi detecting activity - resistor needed?
Replies: 9
Views: 227

Re: Pi detecting activity - resistor needed?

... and if you happen to have enabled the internal pull-down with a 5k external pull-up, the end result is a 4.54545k pull-up to 3.0v - again, almost no difference.
by Burngate
Mon Jan 08, 2018 10:25 am
Forum: Python
Topic: please help me out! timer needed in python script!
Replies: 2
Views: 169

Re: please help me out! timer needed in python script!

The Op's first post, on 19th December, got no replies. That disappointed me, because I would have been interested in any answers (I don't know enough Python to sensibly answer myself) What I was hoping for (and, possibly, the Op also) was advice on using threading. Having now tried the Forum's searc...
by Burngate
Sat Jan 06, 2018 10:29 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Setting up GPIO 15 for the mini UART
Replies: 2
Views: 113

Re: Setting up GPIO 15 for the mini UART

Just for interest, every GPIO can have up to 5 Alt functions.
In https://www.raspberrypi.org/app/uploads ... herals.pdf, page 102, there's a list of most of them (some were deliberately omitted) though the Pi 3B uses some for the WiFi, etc. so they can't be used.
by Burngate
Wed Jan 03, 2018 11:24 am
Forum: General discussion
Topic: Horrible experience trying to get into pi BUYER BEWARE
Replies: 21
Views: 993

Re: Horrible experience trying to get into pi BUYER BEWARE

So, a little help from a friend ... This massive headache of a product experience started about 2-3 years ago. I had attended a class somewhere about raspberry pi and how to program with it, I was fascinated and decided to get one. To make sure I got the best and easiest experience as possible, I de...
by Burngate
Tue Jan 02, 2018 5:18 pm
Forum: RISCOS
Topic: Bundle of questions before starting
Replies: 3
Views: 287

Re: Bundle of questions before starting

1 - Do the BBC basic still allow to switch to assembly. And if Yes, does the neon instructions are allowed ? Yes, you can still use assembler code. No idea about neon, as I've not needed it. 3 - How many second are needed to boot a Raspberry Pi with risc OS. I remember my Archimedes boots so fast. ...
by Burngate
Mon Jan 01, 2018 11:01 am
Forum: Advanced users
Topic: Maximum current and voltage through the 40 pins before damage?
Replies: 11
Views: 401

Re: Maximum current and voltage through the 40 pins before damage?

The way I understand it, too much voltage tends to punch through the insulation of gates, whereas too much current does its damage by over-heating elements. If that's the case, since the output circuitry is just a half-H (two fets, one pulling up, the other pulling down) and they're going to be quit...
by Burngate
Wed Dec 27, 2017 6:15 pm
Forum: General discussion
Topic: What is StrongED
Replies: 15
Views: 569

Re: What is StrongED

I've never actually used StrongED, but I still do stuff with RiscOS. My house is full of Pis, most of which are running it, or at least would be running it if I ever managed to finish the projects. I did eventually manage to get RiscOs on one core and some bare metal stuff on a different core; the R...
by Burngate
Wed Dec 27, 2017 6:04 pm
Forum: General discussion
Topic: Could I remove the under voltage warning on the raspberry pi 3 model B using a voltage regulator?
Replies: 9
Views: 363

Re: Could I remove the under voltage warning on the raspberry pi 3 model B using a voltage regulator?

If "The definition of insanity is doing the same thing over and over again and expecting a different result" as Einstein apparently didn't write, does actually getting a different result mean one is less or more insane?
by Burngate
Tue Dec 26, 2017 11:35 am
Forum: Beginners
Topic: GPIO Pin Audio Speaker, how?
Replies: 1
Views: 71

Re: GPIO Pin Audio Speaker, how?

The short answer is ... you can't. The Pi has no GPIO pins dedicated to speakers, only the 3.5mm jack, and that is only low power so an amplifier will be necessary. Actually you're allowed to do anything you want, but for anything useful, a correctly wired trrs jack connected to an amplifier is the ...

Go to advanced search