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by Burngate
Mon Jun 18, 2018 6:07 pm
Forum: Troubleshooting
Topic: keyboard configuration problem?
Replies: 9
Views: 214

Re: keyboard configuration problem?

Where I come from, braces hold my trousers up, while brackets hold my shelves up. But that's off-topic. What's also off-topic but would also be interesting: given a British pound is an L (again for Libre) where did the two horizontal lines come from? And why is a dollar sign an S, and where did the ...
by Burngate
Wed Jun 13, 2018 10:19 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Circuit using a MOSFET to control power
Replies: 7
Views: 429

Re: Circuit using a MOSFET to control power

That's my understanding, as well. What's drawn is a source follower, a.k.a common drain. Wikipedia has a page. So, as illustrated, an enhancement FET will only turn on while the gate voltage is higher than the output, limiting the maximum output voltage at 3.3V It's even worse than that - the gate-s...
by Burngate
Tue Jun 12, 2018 8:45 am
Forum: Troubleshooting
Topic: Replacement for connector mini hdmi Pi-ZeroW
Replies: 3
Views: 118

Re: Replacement for connector mini hdmi Pi-ZeroW

In a spirit of experimentation - after all, what's it going to cost you? The price of a ZeroW, a connector for a couple of quid, and a year or so extra in purgatory for the blaspheming you're going to do - RS have what looks like the right connector, part No. 163-5383
by Burngate
Mon Jun 11, 2018 5:51 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Use jumper to connect 2 GPIO in PI ZERO
Replies: 1
Views: 227

Re: Use jumper to connect 2 GPIO in PI ZERO

To return 0 when it's not connected, you need to set GPIO20 is input with pull-down, either using the internal pull-downs or with your own external one. To return 1 when it's connected to something, that 'something' must be at (or close to) 3v3. If you wish that 'something' to be GPIO26, then you ha...
by Burngate
Fri Jun 08, 2018 6:22 pm
Forum: Automation, sensing and robotics
Topic: Using a relay to connect GPIO pins and run script
Replies: 1
Views: 191

Re: Using a relay to connect GPIO pins and run script

As far as the Pi's concerned, the contacts of a relay are exactly the same as a switch, so that bit could stay the same - in fact you could keep your momentary switch and wire the relay contacts in parallel with it. Just so long as your script doesn't require the momentary switch to be opened before...
by Burngate
Fri Jun 08, 2018 5:59 pm
Forum: Off topic discussion
Topic: Is the Test / Bench Obsolete
Replies: 8
Views: 945

Re: Is the Test / Bench Obsolete

Recently, one of the key-dongle-things for my Scandinavian car turned up its toes - fortunately I've got a second one. Tried changing batteries, no go. So off to the local dealer. But they wanted £130 !!! For a key-fob!!! Then £more to register it with the car !!! I've tried poking and prodding both...
by Burngate
Fri Jun 08, 2018 5:40 pm
Forum: Troubleshooting
Topic: Red LED only after reboot
Replies: 6
Views: 196

Re: Red LED only after reboot

It's looking more and more likely that that something untoward happened as you connected the camera. One possibility* is that the 3v3 line on the camera connector shorted to somewhere it shouldn't. Does the main chip get hot quickly? *apart from such ham-fisted-ness as dropping it in a pile of coins...
by Burngate
Fri Jun 08, 2018 9:10 am
Forum: Troubleshooting
Topic: Red LED only after reboot
Replies: 6
Views: 196

Re: Red LED only after reboot

kurtisbaute wrote:
Thu Jun 07, 2018 4:44 pm
... Did I fry it by installing the camera while the power was still plugged in?
That is certainly a possibility.
Have you removed the camera and tried it?
by Burngate
Wed Jun 06, 2018 5:57 pm
Forum: General discussion
Topic: How to force audio from jack 3.5 modifying config.txt
Replies: 2
Views: 100

Re: How to force audio from jack 3.5 modifying config.txt

https://elinux.org/RPiconfig , about 1/4 of the way down in the Video mode options section: hdmi_force_edid_audio Pretends all audio formats are supported by display, allowing passthrough of DTS/AC3 even when not reported as supported. hdmi_force_edid_audio=1 hdmi_ignore_edid_audio Pretends all aud...
by Burngate
Wed Jun 06, 2018 10:38 am
Forum: General discussion
Topic: Replacing RPi 2B -> 3B+ : Worth it?
Replies: 27
Views: 955

Re: Replacing RPi 2B -> 3B+ : Worth it?

Is that a statement from One Who Knows, a report from the crow's nest ("still no land on the horizon, Cap'n, but it's a bit misty today"), or Nostradamus reading the runes?
by Burngate
Wed Jun 06, 2018 10:22 am
Forum: Troubleshooting
Topic: Broke off part on Raspi 3 ==> WIFI gone
Replies: 11
Views: 396

Re: Broke off part on Raspi 3 ==> WIFI gone

For what it's worth, measuring across it gives me 1.3Ω both ways.
I've no idea what's around it, but that measurement leads me to think it might be an inductor.
by Burngate
Wed Jun 06, 2018 8:56 am
Forum: Troubleshooting
Topic: pi zero cam not working
Replies: 1
Views: 52

Re: pi zero cam not working

Check that the ribbon cable is seated correctly at both ends.
Check that the 'sunny' connector on the camera board is fully home.
by Burngate
Tue Jun 05, 2018 3:34 pm
Forum: Off topic discussion
Topic: What If I Told You... You could have a bad to the box Matrix Pi
Replies: 59
Views: 2843

Re: What If I Told You... You could have a bad to the box Matrix Pi

drgeoff wrote:
Tue Jun 05, 2018 12:21 pm
(Get the approach line and speed just right and the craft will go into orbit around the planet.)
Will it?
Or put it another way - reverse everything - if a craft is in orbit, can it be ejected from that orbit without a third body?
by Burngate
Mon Jun 04, 2018 5:54 pm
Forum: Advanced users
Topic: Using Raspberry Pi to Send Composite Video to CRT - Getting Started
Replies: 11
Views: 337

Re: Using Raspberry Pi to Send Composite Video to CRT - Getting Started

Because the line frequency was so high, the saw-tooth current applied to the horizontal coils needed to change polarity very quickly, and so a large voltage was needed. That voltage was also rectified to produce the EHT. That is oversimplified to the point of giving an untrue explanation. On reflec...
by Burngate
Mon Jun 04, 2018 10:33 am
Forum: Advanced users
Topic: Using Raspberry Pi to Send Composite Video to CRT - Getting Started
Replies: 11
Views: 337

Re: Using Raspberry Pi to Send Composite Video to CRT - Getting Started

... I have a 4 inch CRT monitor and it's flyback transformer but no driver. I have been patrolling the internet for circuit diagrams and existing projects but have yet to find results. CRTs require several supply voltages in addition to the video signal (applied to the first grid and cathode) The m...
by Burngate
Mon Jun 04, 2018 9:28 am
Forum: Off topic discussion
Topic: What If I Told You... You could have a bad to the box Matrix Pi
Replies: 59
Views: 2843

Re: What If I Told You... You could have a bad to the box Matrix Pi

You are spinning around in some pod on a fairground ride. You feel a force pulling you outward. Centrifugal or centripetal, whichever way you want to look at it. Where there is a force there is an acceleration, Newton's F=ma. Now the fairground ride breaks and your pod goes flying off, it's not rot...
by Burngate
Sun Jun 03, 2018 10:59 am
Forum: Advanced users
Topic: Brief voltage drop on UPS like system. would a capacitor fix it?
Replies: 38
Views: 1326

Re: Brief voltage drop on UPS like system. would a capacitor fix it?

Yes, I'm a retired electronics design engineer with military, automotive, and high-reliability systems experience. My career was somewhat different - TV outside broadcast. Unlike studio engineers, we had to solve problems on the fly, often without ready-made solutions available on the market. And i...
by Burngate
Sun Jun 03, 2018 10:15 am
Forum: Off topic discussion
Topic: What If I Told You... You could have a bad to the box Matrix Pi
Replies: 59
Views: 2843

Re: What If I Told You

So far, two posts have been interesting, so 50% success rate (dropping to 40% when I press the "Submit" button) Wow. Original post title was possibly interesting, modified title less so. First few posts turned out to be more interesting. Now we're onto plant growth, relativity, and anthropomorphism...
by Burngate
Sat Jun 02, 2018 5:33 pm
Forum: Off topic discussion
Topic: What If I Told You... You could have a bad to the box Matrix Pi
Replies: 59
Views: 2843

Re: What If I Told You

... then wonder why you couldn't have told me that so I hadn't put any effort into what I'm not very interested in. The trouble with that is that, if he had told us what it was about, I wouldn't have bothered reading it. As it is, even though I have no interest in the subject, and now know that it'...
by Burngate
Fri Jun 01, 2018 6:12 pm
Forum: Advanced users
Topic: Brief voltage drop on UPS like system. would a capacitor fix it?
Replies: 38
Views: 1326

Re: Brief voltage drop on UPS like system. would a capacitor fix it?

You mean ... pratting around with odd components until it works is better than a bit of theory? I don't think you mean that, at all. You more-or-less describe yourself as professional, though what in area I don't know. The answers you've given to other posts lead me to think you know what you're tal...
by Burngate
Thu May 31, 2018 5:44 pm
Forum: Advanced users
Topic: Brief voltage drop on UPS like system. would a capacitor fix it?
Replies: 38
Views: 1326

Re: Brief voltage drop on UPS like system. would a capacitor fix it?

So "professional" means "it's done in stuff you can buy", so if nobody's doing it, it must be "clutching at straws" -it must be dodgy, somehow. Maybe you're right - maybe no "professional" - i.e. someone who gets paid, not necessarily someone who's good at his job - has used it in a commercial bit o...
by Burngate
Thu May 31, 2018 11:11 am
Forum: Advanced users
Topic: Brief voltage drop on UPS like system. would a capacitor fix it?
Replies: 38
Views: 1326

Re: Brief voltage drop on UPS like system. would a capacitor fix it?

... Professionally, I've never seen anything like that. I would call it clutching at straws. In what way is it that? You said: This is the inrush current I was talking about. It overloads your regulator which then shuts down. The easiest option is to try a smaller capacitor. You may have to accept ...
by Burngate
Thu May 31, 2018 10:46 am
Forum: Off topic discussion
Topic: Forum structure
Replies: 47
Views: 2763

Re: Forum structure

... don't post at all unless you have the courtesy to take the 5 minutes necessary to narrow down what your actual problem is. If they can't use language properly, that makes these forums an even worse place to go to solve their problems. They need someone who knows them, knows how they communicate...
by Burngate
Thu May 31, 2018 9:26 am
Forum: Beginners
Topic: Power in and out pins
Replies: 4
Views: 175

Re: Power in and out pins

Should I supply power to the out pins from the 5V or 3.3V and why? Unless you have a good reason to avoid using the microUSB power input socket, don't supply power to the 5v pins on the header. To do so is to bypass the polyfuse, so reducing safety. Don't supply power to both the uUSB socket and th...
by Burngate
Wed May 30, 2018 6:28 pm
Forum: Advanced users
Topic: Brief voltage drop on UPS like system. would a capacitor fix it?
Replies: 38
Views: 1326

Re: Brief voltage drop on UPS like system. would a capacitor fix it?

How about putting a resistor in parallel with a schottky diode, in series with the capacitor?

On power-up, the cap charges through the resistor (the diode is reverse-biased) so does so slowly.

When power disappears momentarily, the cap supplies current through the diode.
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