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by Burngate
Fri Jul 19, 2019 9:59 am
Forum: Automation, sensing and robotics
Topic: Project Idea getting feedback before I begin
Replies: 8
Views: 118

Re: Project Idea getting feedback before I begin

... I often have complaints of it not being answered or not answered within the 10 minutes we are supposed to answer it. ... Am I to understand you to be the member of nursing staff who would be answering, or are you more responsible for the call system itself? If the former, it may be worthwhile t...
by Burngate
Fri Jul 19, 2019 8:37 am
Forum: General discussion
Topic: Power Supply - Type C of Pi 4 model B
Replies: 14
Views: 660

Re: Power Supply - Type C of Pi 4 model B

Imperf3kt wrote:
Fri Jul 19, 2019 8:00 am
... - power the Pi via the GPIO header, 5v pin/s and ground, or potentially the PoE header, if it can be leveraged for such use.
The PoE header doesn't carry 5v - it takes power from the ethernet socket and passes it to the PoE HAT, which then powers the Pi through the GPIO header.
by Burngate
Thu Jul 18, 2019 5:30 pm
Forum: General discussion
Topic: Raspberry Pi Zero W Power Abbilities
Replies: 5
Views: 196

Re: Raspberry Pi Zero W Power Abbilities

Read somewhere that an LED button can draw 25mA, and with 20 buttons that's 500mA. Plus the 150mA from the Pi I should be good to go. Thanks for the help. The current through an LED depends on how bright you want it, what colour it is (red ones have lower forward voltage than green ones, blue are h...
by Burngate
Tue Jul 16, 2019 9:33 am
Forum: General discussion
Topic: Pi 4 PCB Defect? (fiberglass thread loose)
Replies: 15
Views: 952

Re: Pi 4 PCB Defect? (fiberglass thread loose)

From the description of what it actually is, I suspect a light touch with a fine file would clean it up nicely. I second this. ... Use of a mask is advised. The dust from the resin probably won't be a problem, but glass fibre dust isn't nice - it can get deep into the lungs and cause problems. Mayb...
by Burngate
Tue Jul 16, 2019 8:58 am
Forum: Graphics, sound and multimedia
Topic: How to send a sound signal through gpio pin to speaker?
Replies: 7
Views: 177

Re: How to send a sound signal through gpio pin to speaker?

I have a rpi 3 model b. ... cuz I’ve already got some stuff lying around. If building it from those isn’t recommended, what about a chip like the lm386? To a certain extent, it depends on how deep you want to go - do you want to buy a car, use some sheet steel and wheels and an engine you happen to...
by Burngate
Thu Jul 11, 2019 6:12 pm
Forum: Beginners
Topic: Voltage Sensors with Raspberry Pi
Replies: 2
Views: 90

Re: Voltage Sensors with Raspberry Pi

What is a "25V Voltage Detector Module 3-Terminal Sensor"?

And what sort of "generator"?
by Burngate
Thu Jul 11, 2019 5:47 pm
Forum: Advanced users
Topic: ESD protection diodes on the BCM2711
Replies: 8
Views: 332

Re: ESD protection diodes on the BCM2711

BlastFX wrote:
Thu Jul 11, 2019 3:44 pm
Guess I'll squeeze a proper level shifter in somehow.
A couple of resistors as a voltage divider should work on an input to the Pi, or a FET appropriately wired will work in both directions.
by Burngate
Thu Jul 11, 2019 10:41 am
Forum: C/C++
Topic: I dont get it... Why is everyone from science schools so obsessed with Perl and Python when we got C?
Replies: 183
Views: 4320

Re: I dont get it... Why is everyone from science schools so obsessed with Perl and Python when we got C?

Musketeer wrote:
Thu Jul 11, 2019 8:14 am
C is pure = it is simple! :twisted:
Is it?

Wouldn't it be better to go for assembler, rather than obfuscating everything with a high-level language?
That way, the student will learn what's actually happening.
by Burngate
Thu Jul 11, 2019 9:28 am
Forum: Beginners
Topic: [SOLVED] Can I connect an arduino directly to GPIO using a 10k ohm resistor?
Replies: 9
Views: 211

Re: How to change a title

ZXY007o0ePksrW7L wrote:
Wed Jul 10, 2019 9:15 pm
If this forum supports it and I can figure out how, I'm going to mark this as solved.
Just go to your first post, edit it and change the title - just like I've just done for this post!
by Burngate
Thu Jul 11, 2019 9:03 am
Forum: Advanced users
Topic: ESD protection diodes on the BCM2711
Replies: 8
Views: 332

Re: ESD protection diodes on the BCM2711

Unless it's significantly different from previous SoCs, it doesn't have protection diodes as such - merely parasitic elements that sort of work as clamp diodes, and if significant current passes through one, it's likely to cause latchup and damage the silicon. http://www.mosaic-industries.com/embedd...
by Burngate
Thu Jul 11, 2019 8:47 am
Forum: General discussion
Topic: Charger compatibility with the Pi 4 (Single Type C CC resistor on Pi4)
Replies: 28
Views: 3076

Re: Charger compatibility with the Pi 4 (Single Type C CC resistor on Pi4)

Or a Mondeo engine in a Volvo. Have you done that then? My next-door neighbour runs a repair shop, so when my 10-year-old V70 decided to not even try to start, I asked him for help, and that's what he told me. He also told me the fault wasn't with the engine, or the battery, or the over-complicated...
by Burngate
Wed Jul 10, 2019 5:45 pm
Forum: General discussion
Topic: Charger compatibility with the Pi 4 (Single Type C CC resistor on Pi4)
Replies: 28
Views: 3076

Re: Charger compatibility with the Pi 4 (Single Type C CC resistor on Pi4)

Almost as bad as putting an EEPROM on a Pi.

Or a Mondeo engine in a Volvo.
by Burngate
Tue Jul 09, 2019 6:21 pm
Forum: General discussion
Topic: Micro/type-c USB power supplies immunity to backpowering validity/proof
Replies: 13
Views: 682

Re: Micro/type-c USB power supplies immunity to backpowering validity/proof

If you have been unable to find a USB specification that requires a diode, then assume it's not in the spec. And I agree - manufacturers are quite likely to cut costs where they can. If you're worried, then put your own ideal diode on your board - better safe than sorry, and also cheaper than a lawy...
by Burngate
Tue Jul 09, 2019 5:10 pm
Forum: General discussion
Topic: Micro/type-c USB power supplies immunity to backpowering validity/proof
Replies: 13
Views: 682

Re: Micro/type-c USB power supplies immunity to backpowering validity/proof

I'm not sure I understand - are you designing (for sale) a power supply, or a device that needs a power supply? If you're designing a power supply, then it seems obvious - make sure it won't sink current if another supply is connected to it, by building in an ideal diode or by any other means you wi...
by Burngate
Tue Jul 09, 2019 9:50 am
Forum: General discussion
Topic: Micro/type-c USB power supplies immunity to backpowering validity/proof
Replies: 13
Views: 682

Re: Micro/type-c USB power supplies immunity to backpowering validity/proof

In full, the paragraph reads: NOTE that the Raspberry Pi 3B+ and Pi Zero and ZeroW do not include an input ZVD. The micro-USB input on a Pi is expected to / almost universally is driven by a power source which does not sink current, i.e. it will not try to actively pull down a voltage higher than it...
by Burngate
Mon Jul 08, 2019 5:47 pm
Forum: RISCOS
Topic: RISC OS Pi?
Replies: 30
Views: 973

Re: RISC OS Pi?

... Though reasons one may consider RISC OS include: It is different. Now there is the downside that it is a good bit different to use than other OS's. I tend to see things slightly differently - RISC OS is what I grew up with, so it's all the other OS's that are different. It seems there are a spe...
by Burngate
Sun Jul 07, 2019 9:45 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Pi 1B: Deactivate all LEDs
Replies: 5
Views: 210

Re: Pi 1B: Deactivate all LEDs

I would like to deactivate all LEDs (but ACT = cpu0) of a Pi 1B at startup. Any Ideas how to deactivate the PWR-LED? "/sys/class/leds/led1" does not exist. led0 works fine. If it's really an early Pi - from round 2013 - then you can't. The PWR LED is directly wired to the 3v3 line. From the B+ to 3...
by Burngate
Fri Jun 21, 2019 9:43 am
Forum: Troubleshooting
Topic: Wrong Image Color
Replies: 13
Views: 839

Re: Wrong Image Color

Rupiert wrote:
Fri Jun 21, 2019 6:31 am
So: I have 6 Rpi's (half zero pi's) there all have the same cam.
Do you mean you have only one camera that you swap between the six Pis, or do you have six supposedly identical cameras, one for each Pi?
by Burngate
Fri Jun 21, 2019 9:30 am
Forum: Beginners
Topic: How to turn on a LED
Replies: 8
Views: 936

Re: How to turn on a LED

Any chance you can explain how did you know this board had a split? Is it because the red / blue lines break around row 30? That break in the red and blue lines is certainly a clue, but mainly it's just experience. Most of us have already made the same mistake, some of us several times. The same go...
by Burngate
Tue Jun 18, 2019 5:48 pm
Forum: Off topic discussion
Topic: [FIXED] Ego Search / Own Posts failing
Replies: 59
Views: 9792

Re: [FIXED] Ego Search / Own Posts failing

Depending on your browser, there is a way of fixing the width problem with the forums. I use it with Firefox and it goes full screen width for me no matter which screen I'm using. I have to admit I've not managed to find anything in Firefox like that. It's possible that an update to Firefox disable...
by Burngate
Tue Jun 18, 2019 8:55 am
Forum: Off topic discussion
Topic: [FIXED] Ego Search / Own Posts failing
Replies: 59
Views: 9792

Re: [FIXED] Ego Search / Own Posts failing

A while ago we also lost the Raspberry and the three lined burger menu icon (in mobile/narrow view) from the Title bar I don't use the mobile view (the ordinary one doesn't make enough use of my screen-width as it is - I'm sure it used to go wider, but hey-ho) but the Raspberry going missing is an ...
by Burngate
Mon Jun 17, 2019 5:37 pm
Forum: Troubleshooting
Topic: Pi 3B - Broken SD card slot
Replies: 16
Views: 895

Re: Pi 3B - Broken SD card slot

... Fatigue, caused by? Could it be heat? The Pi wasn't in a very well ventilated case, and was lying under a table in a room thats quite warm for 9 months in a year. No idea -I don't think heat cycling would have caused this - but ... for example, did a vacuum cleaner get anywhere close in that ni...
by Burngate
Mon Jun 17, 2019 10:21 am
Forum: Off topic discussion
Topic: how heavy is raspbian ?
Replies: 30
Views: 3666

Re: how heavy is raspbian ?

Heater wrote:
Sun Jun 16, 2019 6:03 pm
Squeeze enough information into a small enough space and you create a black hole!
I understood that the information stayes on the surface of the black hole - more information, larger area, so bigger and heavier black hole.
If that's so, then you can't squeeze information into a 3D space.
by Burngate
Mon Jun 17, 2019 9:29 am
Forum: Other projects
Topic: Soil sensor (2 nails) ads1115
Replies: 2
Views: 446

Re: Soil sensor (2 nails) ads1115

Why are you using a GPIO to feed the nail sensor? Wouldn't a constant 3v3 be better? You could perhaps use two GPIOs, one to each nail via its own resistor, and one output low with the other output high, and use the A-D in differential mode. Then regularly swapping the low and high around could redu...
by Burngate
Sat Jun 15, 2019 10:31 am
Forum: General discussion
Topic: System start up
Replies: 4
Views: 304

Re: System start up

... the "worst possible consequences"... ... which could be your SD card may need re-imaging. You're unlikely to damage your Pi! And it could be a good learning experience, so try it, and see what happens. It's not like removing the ignition key of a car while driving on a motorway (other than the ...

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