Raspberry Pi Forums

davidcoton

i) my idea is that the audio from pi goes to an audio amplifier, and the audio amplifier goes to the connector which holds speaker and earphone jack, is it possible? ii) I've noticed that an audio amplifier works on 3.3v or 5v usually goes with the speaker up to 8 ohms, but we know the every earpho...

davidcoton

Thanks, that may well be in line with European regs for Class II. I'm just surprised that the requirement is for 5kV because many other parts of an average system will not stand up to that. Commonly regs specify a partial non-ideal answer because it is considered do-able, while ignoring better solut...

davidcoton

that relay is not suitable for an application where the low voltage circuitry is not grounded. your dishwasher is grounded and the low voltage circuitry is not accessible by the user. so it is allowed to use "basic insulation". if you use this type of relay with the Pi and use it to control loads a...

davidcoton

No.The polyfuse is designed to protect the Pi at the specified value. Changing it will reduce that protection, with potentially serious consequences. Notably you could draw too much power through the micro USB connector, causing damage to the Pi.

davidcoton

Hmmm, but with tis I will need add one component in each room. Does exist another alternative ? Probably more than one component per room. Enough components to determine the lamp status by measuring light, applied mains voltage, etc) and to signal that back to your Pi in a safe manner -- safe for h...

davidcoton

@burngate All agreed. The actual "rating" of a conductor is very complex, and includes its material, frequency of the current, ambient temperature, permitted operating temperature, insulation type and thickness (thermal conductivity and survival temperature are both relevant), and where the conducto...

davidcoton

My idea is not usage additional components in curent environment. Eg add Sensors in each environmet. You must have additional components to safely isolate the mains from your RPi. I think the light sensor suggestion is probably easiest to implement safely. By careful with mains electricity. It can ...

davidcoton

Its a linear dimension on mahjongg's posted spec sheet. Its the width of the connector (or the plastic groove it sits in). There isn't a dimension for the depth of the connector. If it was square at 0.38mm it would fuse in 10 seconds at 4 amps according to http://en.wikipedia.org/wiki/American_wire...

davidcoton

So COM has to be connected to the 3V3 if you use the 3V3 as a power supply? I always thought that COM was the negative rail? For example when using a Multimeter? "COM" is short for "Common" -- a single connection for all the parts of the chip. While it is often the 0V rail, that is not necessarily ...

davidcoton

An electrician would be horrified by getting more than a few milliamps through a connector with a maxmum dimension of 0.38 mm. An electrician will go by the spec. If it allows 1.8A, then 1.8A is allowed (other components permitting). An electrical engineer will tell you this. If the allowed voltage...

davidcoton

I understand that if I connect the relay to GPIO25 and ground with a pull-up resistor, the default will be high/on/true and the relay on state will be low/off/false. To get the logic I want, would I connect the relay to GPIO25 and 3.3v with a pull-down internal resistor? I'm not sure what you are s...

davidcoton

There was a change a few years ago to bring the United Kingdom into line with our near neighbours in continental Europe. The nominal voltage for the mains was reduced to 230V (within -6% & +10%) [which gives us 408V across any two balanced phases]. The thing that's rigidly fixed is averaging 50Hz a...

davidcoton

uirsalan wrote:Someone please help me! Thanks in advance.

Uirsalan

Dougie gave you the necessary information. You just don't seem to like it. You will have to find or make a cable that is wired correctly.

davidcoton

READER ALERT: WAY off topic! I'm currently thinking of ways to get a kettle to make toast.... It might be easier to make a toaster boil water. Maybe not too efficient, but could be done without destroying the toaster functionality. Could still be interesting when the toaster pops up.... I would love...

davidcoton

Don't forget to add an external strain relief to the cable or the effort of pulling the cable along may be enough to dislodge your waterproofing. As the cable is also your emergency recovery method a solid strain relief is vital. Agreed. I would not use the cable alone for recovery. Tape a nylon li...

davidcoton

BMS Doug wrote: I'm currently thinking of ways to get a kettle to make toast....

It might be easier to make a toaster boil water. Maybe not too efficient, but could be done without destroying the toaster functionality. Could still be interesting when the toaster pops up....

davidcoton

Would it make sense to strip the outer covering from the 8-core UTP cable, take just two of the pairs and crimp RJ45 plugs on to those (pins 1,2,3 & 6 only). That would reduce the bulk of the cable down to four thin insulated conductors and reduce the size of the holes needed in the waterproofing t...

davidcoton

Each Pi will protect itself, as long as the power is supplied to the micro-USB connector. It is a false economy to not but the connectors and leads -- you will need some alternative (for example to make connections via the unprotected gpio 5V pins). You could fuse each lead at say 1.5A, this will pr...

davidcoton

I use VNC on a Win laptop to view an RPi and on a Win desktop to view a Linux desktop. VNC is fairly slow to transfer larger graphics images, more reasonable with text interfaces. The direct interface (local screen and keyboard) is noticeably faster. Especially true on the RPi which is not fast to s...

davidcoton

@W H Heydt

EarthwormJim wrote:Hi all,

I wonder if anyone has managed to horizontally flip the display output of the raspberry pi. I own an old arcade cabinet with the crt mounted vertically and a mirror above. ...

(Emphasis mine) ... and I too have missed bits like that in replying to other posts!

davidcoton

If I understand you correctly, no-one else knows either. You need a communications path from the Android to the dongle before you can configure the dongle. By definition, if you need to change the configuration to establish communications, you cannot establish communications to change the configurat...

davidcoton

Hi all, In /boot/config.txt, dispaly_rotate=N If find N=3 works for monitors that can be rotated to portrait format. What works will depend on which way the orientation has been shifted. If it comes out upside down when using a value of 3, then try a value of 1. (A value of 2 should invert the imag...

davidcoton

Ah, but you've got an RPi now. That's smart.

davidcoton

Thanks for the reply, but it doesn't work that way either. It will wait for a login on the console -- despite autologin having been enabled (at least I think it was). I can't even get LXDE to start reliably now. If I try starting my program from the console, I get the same problem as in the first po...

davidcoton

When I was 11, half a century ago I dreamed of being able to build a computer/calculator from old rotary telephone dials and relays having seen such a project in a book somewhere. It was another 15 years or so before I got my hands on an actual computer. I can't quite match that, I didn't learnt ab...

Search found 5008 matches

Re: RPi audio solution discussion

Re: Can anyone suggest me a reliable relay board?

Re: Can anyone suggest me a reliable relay board?

Re: Two F3 polyfuse in parallel?

Re: Three way switch and Lamp Status

Re: Two F3 polyfuse in parallel?

Re: Three way switch and Lamp Status

Re: Two F3 polyfuse in parallel?

Re: SN754410

Re: Two F3 polyfuse in parallel?

Re: Low profile GPIO jumpers

Re: Teamspeak DDOS Protection...

Re: Problem With AV output Raspberry PI model B+

Re: Teamspeak DDOS Protection...

Re: PiSub - Need Some Thoughts

Re: Teamspeak DDOS Protection...

Re: PiSub - Need Some Thoughts

Re: External PSU to power a Raspberry PI

Re: Lagging when using VNC. Will having a monitor be differe

Re: Display flipping possibility?

Re: USB WiFi Dongle

Re: Display flipping possibility?

Re: How to convince your not tech savvy parents to buy you a

Re: Autorun Python code on TFT

Re: Coding Questions