@KennetRunner Humm, Kennet and Avon you say - are you looking forward to the link to the the former Wilts & Berks Canal I'm only a few miles from where that will be?
@goldilocks Hang on - over 8K questions and it is a beta how long has this been going on? Strange, I feel a song title there somehow!
@SlySven I was not aware of that, thanks for the link. It's a bit further West than I'm used to (Pewsey to Newbury to Reading sections), but I may explore it when it's linked... :-)
@SlySven It does seem silly leaving long running stable sites in beta limbo (we were there for 3-4 years), but I think the deal right now boils down to resources (the major one probably being getting the site skinned by a designer), and they are proceeding slowly presumably giving priority to higher volume ones.
@KennetRunner Welcome Ken! Your contributions thus far have been appreciated! P.S. Watch out for SlySven...
I'm trying to send two commands to my raspberry over serial. I have the following code:
#include <avr/io.h>
#include <util/delay.h>
#define F_CPU 8000000UL
#define BAUD 9600
int main( void )
{
// BAUD RATE (bits per second)
UBRR0 = ( ( F_CPU / 8 / BAUD ) - 1 ); // 01100111
// CO...
@NickAlexeev It sorta might if you narrowed the possibilities down more first, or otherwise delimited it to make it clearly a question about the Pi or OS software. E.g., If you were looking for a quick way to do a hex dump from serial. Looks like you've solved it anyway :) FYI There is an Arduino.SE as well.
I'll have to watch out for Nick Alexeev as I've just signed up to EESE which that person moderates...! And @KennetRunner BTW it's not me you have to worry about, as an example consider what @Jacobm001 said earlier of @goldilocks: "You're a very strange person... Ever considered writing a memoir?"!
@SlySven I like to think of us as complimentary -- this being probably the most "untough" S.E. board amongst those it overlaps. With a high proportion of users hiding behind shady pseudonyms... >_>
Slightly OT but does the average user of EE actually understand that Mains Voltages can be unhealthy - I've just seen a question there where the question and the answers are about driving one or more LED from the Mains and nowhere was there a mention that the proposed circuits are literally live and should be kept apart from an extraneous conductor such as the human finger...! =:-!
There are more than a few ways to drive LEDs directly from AC mains, among them:
In 1 and 2, half of the LEDs will be driven during the mains' positive half-cycle, and the other half during the negative half-cycle.
With 50 Hz mains, each string will half-wave rectify the mains and flash at 25...
@SlySven Hmmm -- I only look at it semi-regularly but generally think of them as pretty fastidious WRT pointing out regulations at least. I guess it could be that high voltage is just so commonly involved warning everyone all the time would get tedious, sort of like "Be careful as root kids`..." I'd probably rather trash a filesystem than eat 120V @ 15A though. Been a long time. Pretty scary, esp. since my high school electrical shop teacher told us the most common cause of
electrocution death is actually later that day after you go to sleep and never wake up, something about a potential effect on the bloodstream...
Well I am not finding much about that online, perhaps my high school shop teacher was a clown.
But at least your supplies are 55-0-55, aren't they, where both conductors are around 55V peak away from a centre earth. Over this side of the pond we use 230-0 i.e. one conductor is the full voltage and the other is (close-to) the ground potential (it is connected to ground at the point where the voltage is generated, usually a transformer secondary winding but earth loop impedance means a voltage can be developed between local earth/chassis and the "neutral" conductor.)
Which as I am overhauling a 6.0KVA 240Vac generator means when I get it working and use it to power some stuff away from home means a 1 to 2 meter cordon around the earth spike if I plan to power more than one thing at a time.
I mean I knew Europe was 240V -- I don't understand AC very well, so I will have to mull. I got all nervous the other day just fixing a 24V electric recliner.
(Electric recliners are a seriously dumbass idea BTW)
I understand that 55Vac is just about survivable - on the other hand the current flow for a 240Vac shock is often great enough to cause muscle contraction strong enough to free the touching body part from the voltage source - whereas 50-60V is enough to lock the muscles to prevent voluntary release...
@SlySven The time I did it was installing a household circuit (switches, light fixtures, plugs, etc.) I believe my arm jumped back pretty fast, I would have been wearing shoes, probably on the bare concrete.
For me it was a series chain of 20 x 12V fairy lights with a loose wire on one bulb holder half-way down the chain, the lights were off (so I thought "no power") and I leaned in with my hot soldering iron to resolder the connection. Fortunately the iron was earthed and the current went down the tip and into the earth connection. After that I was unable to repair the lights as it burnt a big hole in the metal holder I wanted to solder and blew-up the iron as well...
@SlySven Okay so then you'd only get a full 110V shock if you grabbed a wire in each hand; if it was just one wire through to ground it would be a mere 55V.
... that should be ok, as long as the meter is not an insulation tester - those b*****s generate a 500Vac test voltage internally to put across the probes to see how much current flows (a souped-up ohmmeters for use on unpowered domestic or commercial electrical systems) - now that does make you take notice! {I actually have a Wee Megger}
@goldilocks Well there are alternative locations which give more consistent results (apparently) but they are not so ready accessible under normal circumstances!
and provide something that would be unsafe if tried in Europe despite the text assertion: "WARNING: For countries with 110v mains, we'd be working with voltages of 150 volts! For Europe and other countries, we are talking about 300 volts or more! At these levels, electricity is lethal! Do not continue unless you are comfortable with working with high voltages and are aware of the precautions to take!" - like don't touch it when it is plugged in.
"​Wouldn't this circuit be deemed (lethally) unsafe in Europe, all that stands between a finger touching one of those LEDs on the outside and the mains on the inside, is the plastic insulation of the LED and THAT does not count as even "Basic Insulation" does it?"
But I'd have to log in to do so and quite frankly why would I sign up to somewhere that allows such things to be unchallenged.
*dismounts from his high-horse* and goes off to get a fresh coffee. BFN
I'm trying to send two commands to my raspberry over serial. I have the following code:
#include <avr/io.h>
#include <util/delay.h>
#define F_CPU 8000000UL
#define BAUD 9600
int main( void )
{
// BAUD RATE (bits per second)
UBRR0 = ( ( F_CPU / 8 / BAUD ) - 1 ); // 01100111
// CO...
There are more than a few ways to drive LEDs directly from AC mains, among them:
In 1 and 2, half of the LEDs will be driven during the mains' positive half-cycle, and the other half during the negative half-cycle.
With 50 Hz mains, each string will half-wave rectify the mains and flash at 25...
The Bakery
The Bakery