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by Z80 Refugee
Tue May 29, 2018 8:57 am
Forum: Automation, sensing and robotics
Topic: Sensing 50Hz frequency deviation fast
Replies: 18
Views: 1441

Re: Sensing 50Hz frequency deviation fast

I agree... at face value. There would still remain a problem guaranteeing the subsequent processing of the pigpio output to produce a useful effect. As far as I can tell, the pigpio library uses hardware interrupts to capture GPIO state and put it on a queue. That's not much help if the OP then want...
by Z80 Refugee
Tue May 29, 2018 8:39 am
Forum: Advanced users
Topic: Brief voltage drop on UPS like system. would a capacitor fix it?
Replies: 53
Views: 6146

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

Yes. Your problem may be that the instantaneous current requirements of the processor under peak load is exceeding the ability of the regulator to react. Adding a smoothing capacitor to the supply lines provides localised energy storage that can supply brief periods of peak demand while the regulato...
by Z80 Refugee
Tue May 29, 2018 7:49 am
Forum: HATs and other add-ons
Topic: 12V fan without additional power supply - summary
Replies: 19
Views: 4256

Re: 12V fan without additional power supply - summary

I am useless with electric so perhaps my settings on the multimeter are incorrect? They are! Here's what you have been asked to do: 82F1EE2D-4131-4639-83AC-C4B1BE84ED34.jpeg The meter you have showed us has three probe connections. The bottom connection is for the -ve probe. The middle connection i...
by Z80 Refugee
Mon May 28, 2018 9:19 pm
Forum: General discussion
Topic: Automotive grade power supply
Replies: 3
Views: 520

Re: Automotive grade power supply

Okay, well as long as you understand this won't cut the mustard commercially and you (and any friends you pass it on to) understand you will be operating very much at your own risk (something to be carefully considered when dealing with potentially lethal machinery, in public, and in a situation tha...
by Z80 Refugee
Mon May 28, 2018 6:46 pm
Forum: Beginners
Topic: Connect 250 RGB leds
Replies: 5
Views: 404

Re: Connect 250 RGB leds

PeterO wrote:
Mon May 28, 2018 5:29 pm
These are devices like the WS2812
That's the equivalent of building an RGB LED controller into the LED itself.
by Z80 Refugee
Mon May 28, 2018 6:41 pm
Forum: General discussion
Topic: Automotive grade power supply
Replies: 3
Views: 520

Re: Automotive grade power supply

This won't be easy. At the input side, you need to accommodate potential accidental reverse polarity (somebody connects a battery the wrong way around), voltage dips and spikes, and "load dump" (the alternator output suddenly losing regulation and reaching 60V or more). You need to ensure the unit c...
by Z80 Refugee
Mon May 28, 2018 5:24 pm
Forum: Beginners
Topic: Connect 250 RGB leds
Replies: 5
Views: 404

Re: Connect 250 RGB leds

But then I’ve also heard that I can just use one pin per led and still be able to change the colour how I want If this is possible I don't know about it. To have complete control over colour you need to control the intensity of red, green, and blue separately. Look up "RGB LED Cube Project" to get ...
by Z80 Refugee
Mon May 28, 2018 5:15 pm
Forum: General discussion
Topic: Connecting pc to tv with raspberry pi
Replies: 15
Views: 1761

Re: Connecting pc to tv with raspberry pi

Here's a solution (but not via Ethernet or an RPi): USB to HDMI Video Adapter This uses Windows' built-in ability to use USB-connected video adapters alongside the PC's own video adapter. There is no such ability to do this over Ethernet, although there are solutions which provide remote desktops (i...
by Z80 Refugee
Mon May 28, 2018 5:03 pm
Forum: HATs and other add-ons
Topic: 12V fan without additional power supply - summary
Replies: 19
Views: 4256

Re: 12V fan without additional power supply - summary

If you can't tell where it's coming from, don't worry about it.
by Z80 Refugee
Mon May 28, 2018 4:56 pm
Forum: General discussion
Topic: Connecting pc to tv with raspberry pi
Replies: 15
Views: 1761

Re: Connecting pc to tv with raspberry pi

I was wondering if I could program the raspberry pi to be a Ethernet to hdmi video converter. No. First of all, you would need to find a way to make the PC output its video to Ethernet. Your best bet is to use a Remote Desktop, but how do you propose to set anything up on the PC? Just get a new cab...
by Z80 Refugee
Mon May 28, 2018 12:18 pm
Forum: General discussion
Topic: Connecting pc to tv with raspberry pi
Replies: 15
Views: 1761

Re: Connecting pc to tv with raspberry pi

Xavier Darkwell wrote:
Mon May 28, 2018 10:50 am
How do I use a raspberry pi 3 as a Ethernet to hdmi converter.
We don't know what you want to do; we're not mind readers.
by Z80 Refugee
Mon May 28, 2018 9:57 am
Forum: Beginners
Topic: How do I use my macbook pro as a monitor for my raspberry pi?
Replies: 4
Views: 2446

Re: How do I use my macbook pro as a monitor for my raspberry pi?

I do not possess a HDMI monitor which I could use for my raspberry pi Yes, VNC. Otherwise: you're not supposed to need an HDMI monitor, the idea is to connect it to your TV. The concept is "low cost of entry", much like the early days of home computers when the likes of Sinclair made it accessible ...
by Z80 Refugee
Sun May 27, 2018 11:06 pm
Forum: Automation, sensing and robotics
Topic: Sensing 50Hz frequency deviation fast
Replies: 18
Views: 1441

Re: Sensing 50Hz frequency deviation fast

The problem here (as I see it) is that the standard OS for the RPi is not what we call "real time". That means you can never rely on program execution to look at some input at or even near exactly the right time, because you cannot guarantee execution won't have been interrupted off somewhere to do ...
by Z80 Refugee
Sun May 27, 2018 7:47 am
Forum: Other projects
Topic: 12V Fan on PI GPIO
Replies: 3
Views: 678

Re: 12V Fan on PI GPIO

by Z80 Refugee
Sat May 26, 2018 10:45 am
Forum: General discussion
Topic: The secret to connecting the 3 pin of the RPi with a single charger
Replies: 4
Views: 468

Re: The secret to connecting the 3 pin of the RPi with a single charger

All good points. You could source LiPo cells with built-in power management, but if not you must use a regulator/converter with LiPo management functionality. Of course, a single LiPo cell can be stepped up to 5V, but I envisaged a gang of three or four providing current to two step-down converters....
by Z80 Refugee
Sat May 26, 2018 8:08 am
Forum: Troubleshooting
Topic: Motor Controllers With Raspberry instead of Arduino - lack of software support
Replies: 10
Views: 741

Re: Motor Controllers With Raspberry instead of Arduino - lack of software support

BEWARE of using interfaces designed for Arduino with an RPi. Arduino uses a 5V interface, RPi a 3.3V interface. Connecting an RPi input to an Arduino-compatible output could be damaging, and connecting an RPi output to an Arduino-compatible input may not work.
by Z80 Refugee
Sat May 26, 2018 7:59 am
Forum: Beginners
Topic: Raspberry pi 3 b+ with powerbank
Replies: 19
Views: 10997

Re: Raspberry pi 3 b+ with powerbank

That's why I am asking. How I find what current can a powerbank or battery in general (Lead Acid for example) can provide without destroying it? I cannot believe I can use 20 A for an hour, from a 20000mAh powerbank, there must be some limit...Right? Correct, and unless you can find a specification...
by Z80 Refugee
Sat May 26, 2018 7:48 am
Forum: General discussion
Topic: The secret to connecting the 3 pin of the RPi with a single charger
Replies: 4
Views: 468

Re: The secret to connecting the 3 pin of the RPi with a single charger

There is no particular problem with running muplitple RPis from one battery pack. All you need to make sure of is that the regulator between the battery and the RPis is capable of supplying the current needed. What you could do is have separate regulators - one for the Pi3 and another for the two Pi...
by Z80 Refugee
Fri May 25, 2018 9:30 pm
Forum: Other projects
Topic: advice from anyone with case printing experience
Replies: 7
Views: 1254

Re: advice from anyone with case printing experience

scruss wrote:
Fri May 25, 2018 12:57 pm
MP Select Mini 3D Printer
Nice! And once you have a basic 3D printer, you can use it to print parts for your next 3D printer.
by Z80 Refugee
Fri May 25, 2018 9:39 am
Forum: Beginners
Topic: Raspberry pi 3 b+ with powerbank
Replies: 19
Views: 10997

Re: Raspberry pi 3 b+ with powerbank

...but it's unlikely the powerbank would be able to supply 5A in the first place.
by Z80 Refugee
Fri May 25, 2018 9:38 am
Forum: Camera board
Topic: Video Editing
Replies: 5
Views: 637

Re: Video Editing

No idea. I'm just pointing you in the right direction.
by Z80 Refugee
Fri May 25, 2018 9:36 am
Forum: Other projects
Topic: advice from anyone with case printing experience
Replies: 7
Views: 1254

Re: advice from anyone with case printing experience

I've not printed a case, but I have done a little 3D design and print. > 2/any recommended (free) software I can use (blender does not like me) I use FreeCAD. It takes a bit of learning and it helps if you have 2D drafting experience, but even then the concepts of extending that to 3D require quite ...
by Z80 Refugee
Fri May 25, 2018 9:15 am
Forum: Beginners
Topic: Raspberry pi 3 b+ with powerbank
Replies: 19
Views: 10997

Re: Raspberry pi 3 b+ with powerbank

Agreed. I was explaining in terms of a steady current because it makes the maths easy, but how long 20Ah lasts is very dependent on the actual current demand from the RPi in the application. The point from the first post is that the RPi will have a peak current demand during boot and other intensive...
by Z80 Refugee
Fri May 25, 2018 9:09 am
Forum: Beginners
Topic: Raspberry pi 3 b+ with powerbank
Replies: 19
Views: 10997

Re: Raspberry pi 3 b+ with powerbank

The output of the powerbank will be regulated to exactly 5V. When the charge runs out, it will drop below 5V very rapidly (and cut out). With a 20Ah capacity, the powerbank should supply current at 5V for however long it takes to use up that capacity. 1 amp for 20 hours = 20Ah (amp-hours). 0.5A for ...
by Z80 Refugee
Fri May 25, 2018 8:10 am
Forum: Camera board
Topic: Video Editing
Replies: 5
Views: 637

Re: Video Editing

Is there an editor, or a codec, which would allow the .h264 video to be edited directly? It depends what you mean by "edit". Video encoding relies on the concept of I (intra) frames and P (predicted) frames. I frames stand alone, while P frames use the I frames to reduce the amount of data necessar...

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