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by Burngate
Fri Aug 17, 2018 8:28 am
Forum: Troubleshooting
Topic: Raspberry Pi 3 Model B+ Won't Boot - Beginner Out of Ideas
Replies: 25
Views: 640

Re: Raspberry Pi 3 Model B+ Won't Boot - Beginner Out of Ideas

4wd wrote:
Fri Aug 17, 2018 6:17 am
PP7: 5.25V
PP8: 5.7mV
PP9: 2.6mV
PP10: 1.89V
PP7 is 5v in, after the polyfuse.
PP8 should be 3v3. Obviously incorrect, at 5.7mV
PP9 should be 1v8. Since this should come up after 3v3, this isn't surprising.
PP10 is the top of the PWR LED. At 1v89, it's glowing!
by Burngate
Fri Aug 17, 2018 8:16 am
Forum: Troubleshooting
Topic: Raspberry Pi 3 Model B+ Won't Boot - Beginner Out of Ideas
Replies: 25
Views: 640

Re: Raspberry Pi 3 Model B+ Won't Boot - Beginner Out of Ideas

3v3 is the main supply to the CPU It's derived (along with several other supplies) from the 5v input, using a specially designed chip - MXL7704, square thing near the power in connector. To measure it, you can use pin 1 of the GPIO header - though be careful - pins 2 and 4 have 5v on them; you don't...
by Burngate
Wed Aug 15, 2018 9:58 am
Forum: General discussion
Topic: Is my Raspberry Pi 3 model B damaging my USB micro cables?
Replies: 4
Views: 167

Re: Is my Raspberry Pi 3 model B damaging my USB micro cables?

The first thing you're going to be told is: to power your Pi, use the official supply, not any old charger you happen to have arround. Fast chargers work by raising the voltage above 5v when asked to do so. This is not a good idea, as the Pi needs 5v, no more, no less. You appear not to have damaged...
by Burngate
Wed Aug 15, 2018 9:38 am
Forum: Off topic discussion
Topic: Good news.... Well, maybe...
Replies: 9
Views: 385

Re: Good news.... Well, maybe...

W. H. Heydt wrote:
Tue Aug 14, 2018 11:12 pm
Can you think of *any* feature--and, particulary, I/O feature--that has ever been removed from a Pi?
P5 - the pcm audio interface, appeared on Pi 1 rev 2, disappeared on B+
by Burngate
Wed Aug 15, 2018 8:35 am
Forum: Troubleshooting
Topic: Ethernet port has no lights turned on
Replies: 12
Views: 207

Re: Ethernet port has no lights turned on

Not wanting to divert the thread into off-topic discussions, but since the OP has resolved his issue ... ... Desktop PCs and laptops will often work even with these cables because they will automatically switch to 10/100 byte networking, which only requires 4 working cores. Are you saying the Pi won...
by Burngate
Tue Aug 14, 2018 8:54 am
Forum: Advanced users
Topic: (solved) Disable red power led on 3B+
Replies: 8
Views: 280

Re: Disable red power led on 3B+

The trouble with the BluTack method is applying / removing it in software. If you're willing to hack the board, there's a pad, PP10, at the top of the LED. A FET from that to ground could be controlled by a normal GPIO - choose one that defaults to pull-down (so not GPIOs 0-8) and it should work nor...
by Burngate
Mon Aug 13, 2018 11:58 am
Forum: General discussion
Topic: (Solved)Which models of USB HDD work when connected directly to the PI?
Replies: 13
Views: 337

Re: Which models of USB HDD work when connected directly to the PI?

According to jbudd, the Pi-drive is discontinued - it is 2½ years since that blog.

The Pidrive cable seems to be still available, but it seems it's relying on a separate power supply.
by Burngate
Mon Aug 13, 2018 9:05 am
Forum: Wanted
Topic: Need Raspberry Pi
Replies: 4
Views: 221

Re: Need Raspberry Pi

It might be worth-while indicating your location.
Who knows, if you're within walking distance, even I might be willing to help. But no further than a mile or so.
by Burngate
Mon Aug 13, 2018 8:44 am
Forum: General discussion
Topic: Difference between GPIO_GEN and GPIO
Replies: 2
Views: 99

Re: Difference between GPIO_GEN and GPIO

The origin of your confusion is basically historical Deep in the dark and distant past, the designers of the first Pi were trying to make things simple for a first-time user. So they arranged for several busses to be broken out to a 26-way connector - an I2C bus, an SPI bus, and a UART - and, becaus...
by Burngate
Sat Aug 11, 2018 10:22 am
Forum: Add-ons
Topic: ETA for Official POE Hat for 3B+
Replies: 20
Views: 626

Re: ETA for Official POE Hat for 3B+

Nice.
Apart from telling us that the fan is spi-controlled, or at least there's (possibly) access to the spi on a 8-pin header, it also tells us that ETA is before January 2023
by Burngate
Fri Aug 10, 2018 10:33 am
Forum: Advanced users
Topic: What value are those parts?
Replies: 36
Views: 907

Re: What value are those parts?

... And when the BBC Micro was around ... The world has changed, whether people like it or not. Those were the days ... I remember when mobile phones were brick-sized, and schematics were printed on actual paper! Why not ditch silkscreen printing on the actual device, just upload JPGs of front and ...
by Burngate
Fri Aug 10, 2018 8:55 am
Forum: Graphics, sound and multimedia
Topic: Volume level restricted to 90dB
Replies: 3
Views: 112

Re: Volume level restricted to 90dB

https://www.britannica.com/science/decibel
Saying something is 90 dB is just saying it's a billion times more powerful than something else.

What that something else is could be an ant scratching a banana at six feet, or Mount St. Helens at sixty miles.
by Burngate
Thu Aug 09, 2018 7:56 am
Forum: Advanced users
Topic: What value are those parts?
Replies: 36
Views: 907

Re: What value are those parts?

Yes, that much is reasonable. It would have been useful in this instance to aid identification, provided one had the full schematic, though having that available is a bad idea for other reasons (if that weren't true, Eben would have let us have it; since he hasn't, it must be true) But ... The Pi is...
by Burngate
Wed Aug 08, 2018 5:01 pm
Forum: Advanced users
Topic: What value are those parts?
Replies: 36
Views: 907

Re: What value are those parts?

hippy wrote:
Wed Aug 08, 2018 12:46 pm
Some boards may have "C1", "R1" etc identifiers silk-screened on them, others may only have values indicated, "100nF", "27R" etc. Latest Pi boards have neither for most components.
Interesting thought. The silk-screen identifiers are irrelevant for assembly
So why do some components have them?
by Burngate
Wed Aug 08, 2018 10:08 am
Forum: Off topic discussion
Topic: Definition of ironic
Replies: 32
Views: 882

Re: Definition of ironic

With >85k left hands and a similar number of right hands, it would be surprising if they all knew what the rest were doing.
by Burngate
Wed Aug 08, 2018 9:31 am
Forum: Troubleshooting
Topic: issue with voltage supply
Replies: 9
Views: 202

Re: issue with voltage supply

That doesn't answer any of the questions. As to the 5v from the Pi: Assuming you're using the "official" supply, it is sufficiently stable and has thick enough wires to maintain the voltage at the Pi within spec. while the Pi is idling up to running full-tilt. But it does not and cannot have zero ou...
by Burngate
Wed Aug 08, 2018 9:15 am
Forum: Off topic discussion
Topic: Definition of ironic
Replies: 32
Views: 882

Re: Definition of ironic

It does seem odd that Google would want to strangle the charity to which they've given more than half a million quid
https://www.raspberrypi.org/about/supporters/

Sorry, bensimmo, missed your post. The internet here in the south is about an hour behind Yorkshire.
by Burngate
Wed Aug 08, 2018 8:47 am
Forum: Troubleshooting
Topic: Bricked Pi, Mounting Holes
Replies: 9
Views: 210

Re: Bricked Pi, Mounting Holes

In future use nylon standoffs and screws?

The Pimoroni standoffs are M2.5, 10mm long.
Many, many places sell nylon versions, and nylon screws as well.

Though, if you go that route, you'll probably find that while you're screwing them in, your screwdriver slips
by Burngate
Wed Aug 08, 2018 8:28 am
Forum: General discussion
Topic: re-imaging RASPI's SD Card on the fly
Replies: 7
Views: 363

Re: re-imaging RASPI's SD Card on the fly

Stepping further out of my comfort zone than I usually like doing - and probably entering Lion's Mane Jellyfish territory - why can it not be done? So it's running from the SD card. But surely everything necessary could be put into memory, so it's now running from RAM - https://www.raspberrypi.org/f...
by Burngate
Wed Aug 08, 2018 8:11 am
Forum: Advanced users
Topic: Questions about Pi to replace car stereo...
Replies: 5
Views: 169

Re: Questions about Pi to replace car stereo...

At the moment, the car has a factory-fitted radio, and a separate factory-fitted amp? If I were the designer of an amp that's going to be factory fitted, I'd make provision for auxilliary inputs, so the end-user could plug in his DVD / CD / cassette player. Have a look, see if you can find such a so...
by Burngate
Wed Aug 08, 2018 7:58 am
Forum: Advanced users
Topic: 3B+ trrs jack audio voltage level
Replies: 14
Views: 423

Re: 3B+ trrs jack audio voltage level

So, If I were to use a standard stereo or mono audio cable the video would just go to ground? Yes. It's designed to be used that way - with standard earbuds. The video circuit can happily be grounded without harm Also, if I were to combine the stereo audio outputs into mono would that double up the...
by Burngate
Tue Aug 07, 2018 5:21 pm
Forum: Troubleshooting
Topic: issue with voltage supply
Replies: 9
Views: 202

Re: issue with voltage supply

What, may we ask, is the sensor?
And how are you connecting it to the Pi - via an ADC? And how is that powered, and how is its reference supplied?

And, of course, pcmanbob's question, how are you measuring these fluctuations?
by Burngate
Tue Aug 07, 2018 9:24 am
Forum: Beginners
Topic: Controlling a 12V Fan with a MOSFET?
Replies: 4
Views: 89

Re: Controlling a 12V Fan with a MOSFET?

Yes, that PiHut fan can be driven by a RPi, and the 2N7000 FET is suitable. The schematic in the NerdKits page is ideal - in fact I like the description of how a fan motor works, and the details of the FET. Several things might be of interest. The fan he's using is 9v, while the one you want to use ...
by Burngate
Tue Aug 07, 2018 7:49 am
Forum: Advanced users
Topic: 3B+ trrs jack audio voltage level
Replies: 14
Views: 423

Re: 3B+ trrs jack audio voltage level

No. Tip = left, ring = right, ring = ground, sleeve (you called last ring) = video.

Raspberrypi-spy has a good description (as with many things)
https://www.raspberrypi-spy.co.uk/2014/ ... ideo-jack/

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