DIY Pedestrian Crossing

[dennis]

Just think.. there wouldn't be any need for anything other than zebra crossings if the stupid drivers weren't around.

[dennis]

That is usually because the driver has crossed the line for cars and is in the green box at the stop line for bikes.

[Harry Bloomfield]

Invisible Man submitted this idea :

PIR - if you don't move, you become invisible to the sensor.

[Harry Bloomfield]

It's one of those barriers where making a start on the learning, drags you into it, it is knowing how where to start. Tandy/Realistic used to sell some very basic engineers notebooks, in a series magazine size editions. They were full of quick simple experimenters circuits, which often had little purpose other than to allow you to experiment with devices, mixed in with a few useful items. All of that, along with much of the supply of components has gone. Even Maplin, who seemed to take over Tandy's market are stocking fewer and fewer components as the years go by.

pic's and software seem to be the way to go now.

[Andrew Gabriel]

I don't think there is still any magazine which was at the level of Everyday Electronics, although I must admit I haven't checked the magazine shelves for many years now. Elektor was somewhat more advanced, and not really beginner stuff.

I wonder if there's much interest in this area by today's youth?

I mostly use CPC, Farnell, and Rapid now. I still use Maplin for emergencies (non-mail-order), and the odd thing they still stock which others don't, but their reduction in components stocked is probably around the point where they can't keep critical mass, sadly. I did buy quite a number of the components for the crossing from Maplin in Farnborough, but for each of the LED types I wanted, I took all their stock (in some cases having had to chose a different part as they were out of stock in the first place).

For logic, yes. I also do analogue.

[Frank Erskine]

Sadly I think not. Most of today's youth seem to expect any electronic gadgetry to be prebuilt for them (probably by Far Eastern manufacturers), and to have 'scores' displayed on an LCD screen.

Basic electronic skills such as soldering, measuring voltages and currents etc are rarely nurtured or taught in schools nowadays, and frankly most simpler projects such as crystal sets are becoming obsolete in the wake of DAB and so on. It's so much easier too, to pick up a mobile phone than build a pair of walkie-talkies...

However, your pedestrian crossing project sounds very interesting. I've heard of all these different types of crossing, and used them, but I still couldn't identify them by name - the only one I know by name is the good old-fashioned zebra crossing :-)

[John Rumm]

That's not really the whole picture though is it. It might work for the pedestrians, but on a route with lots of em arriving in a non stop stream, it would cause traffic gridlock. The lights controlled crossing at least allows batches of cars to pass every so often by forcing the pedestrians to wait occasionally.

[John Rumm]

What sort of development/debugging environment do you use for PIC stuff like that?

(There are times where I often fancy doing something on a similar scale of complexity, but most of the traditional embedded systems kit I work with is way OTT for that sort of application, not to mention silly money)

[John Rumm]

Sadly I would tend to agree. You only need look at the growth of Maplin and its need to deviate from what was once its core business in order to sustain that growth to see that electronics as a hobby is nothing like it once was.

(As I have commented here before - I grew up living close to the original Maplin shop. It was a place of wonder in some respects those days. People would wander in off the street, and describe some electronic wizardry they fancied constructing. The shop assistant (electronics graduate typically) would retrieve a pencil from behind his ear, sketch a quick circuit design, grab the shop calculator and do some sums to work out component values etc, before wandering off and finally returning 5 mins later with a plastic bag containing all the components required having found them in all the various (non self service) racks and bins!) It ain't the same now.

I get a feeling that may have changed a bit with the younger generations now. Our 8 yo has done a fair bit of basic circuit theory in class, and they have done practical stuff with switches, and lamps and simple circuits. Far more than I remember being taught until starting physics in secondary school.

That is true. The impact of low cost imports from China etc has also put pay to many projects - it used to be you can have fun building something and make a big saving on buying a complete item. These days electronic kit from the far east is so cheap as to render that part of the argument a non starter.

Wot, not even a pelican?

[Mike Barnes]

Why so sad? Today's inquisitive kids learn how to construct their own PCs or web sites rather than their own doorbells/amplifiers/etc, but the engagement and rewards are just the same. In my youth I'm sure there were some old codgers around who rued the fact that we didn't make our own resistors.

[Andrew Gabriel]

I built this using a PICAXE-28X1 Chip (which is way over-kill for this application, but that's what I have a prototyping/programming board for), and it's very fast/easy to program. All you need to program it is the PICAXE-28X1 Starter Pack (and the ability to add

8 LEDs and resisters to its outputs so you can see it working), a Windows system with a serial (or USB) port, and some spare chips. Rapid sells all the stuff, and it's not expensive.

PICAXE is just a standard PIC chip, preprogrammed with a serial boot loader and run-time environment, which you can use over and over again (providing you don't trample on the boot loader), so you don't need an expensive programmer.

I've attached the program below, so you can see how simple it is to program.

[Huge]

What he said.

Blimey. That brings back memories. I did a project (*) once using Texas Instruments 5TI PLCs, whose programming language looked very similar to that. Except they were the size of a small suitcase, not a single chip.

(* Automated biscuit factory, using multiple 5TIs being controlled from a PDP11.)

[Bob Eager]

Yes...we have some of that stuff too. My son's first soldering project was building a PICAXE-08M board.

We did traffic lights! The latest was a prototype for an epee (fencing) score/hit box.

If the chip is damaged, it's usually only a pound or two for a replacement anyway.

I just bought a PICkit 2 Debug Express board for £9.99 inclusive (special offer, normally 40 quid plus carriage) via a special offer in a magazine...

[Invisible Man]

I did wind a resistor or 2. First radio I built used 2 valves and LT and HT batteries. First FM tuner I built was on a tin plate chassis and took forever to adjust. Now can't even add a socket in my kitchen. Back to gripes about Part P!

[John Rumm]

Nothing wrong with that, although it does move them a step further away from understanding what they are actually doing. Building stuff from "black boxes" is fair enough, you you gain added insight if you have at least seen inside a few.

more than likely ;-)

[andrew]

Yes, zebra crossings don't work in high pedestrian traffic densities.

It looks like they're only used in less than 40mph zones too.

If Andrew wants to scale up his design we've been quoted GBP90k for a pedestrian controlled crossing onto the public open space here. It's daft really because a zebra crossing would do but the traffic moves too fast for one.

AJH

[geoff]

Exactly the same with Watford Electronics

[dmc]

When he is a bit older, there is the RCX stuff, and the newer version (I've not got one yet :-( ) - the NXT.

Then of course you can head off with things like

get as sophisticated as you want :-)

Darren

[geoff]

In message , Andrew Gabriel writes

You know what you've forgotten don't you ?

The button for pedestrians to press which just beings on the "wait" light

[Bob Eager]

I expect you can borrow one at work!

Son has the NXT, and a load of extra Lego. I have an RCX brick which I've repaired, but nothing to go with it...I fancy a bit of Java programming for it..