gottit!

Well, I managed to sort out all the problems I was having with the control board. A wild combination of the wrong components and stupidity. Indeed, some of the wrong components were down to my stupidity so I doubled up there. The switches had seemed just what I wanted when I bought them but turned out to be not quite as robust or well designed as I had assumed. I have had to make several changes to my board in order to make them work.
So
As this is a diary of work done, this is what went wrong.
My first circuit was built on a breadboard and was, basically, only a single channel version to test the combination of hardware and software. It worked well so I moved on to the next stage.
Which was a hard wired version built on a small PCB version of the breadboard. This was for two reasons, firstly I didn't have any standard  Vero board at that precise moment and secondly, I was keen to try out the other type of board. Well, "More haste, less speed" as I made a simple mistake with the resistors and, as they were very close together, it was difficult to spot.
The wrong component problem was that the switches were ideal on paper but not so great in practise. They have a built in LED that has separate leads for the LED and switch connections and that was what was needed for my circuit. They were also cheaper than the only other version I had seen which is sold by Maplin.
So I bought five on the basis that, as I needed four, I would have a spare to cover me damaging one or, hopefully, one to play with after finishing the project. Well, they all arrived damaged due the seller not protecting them for the post. I managed to straighten out all the leads but one of the LEDs was not working so that left me with just the four working items.
My final problem was more to do with inexperience as I hadn't used modern PCBs before and still feel happiest with standard sized Vero board.
I assembled the PCB for the switches and began to check it out, nothing worked so I had to remove some wiring and start again. The copper simply peeled off with the solder so I had to bodge the connections when I reconnected correctly. The wires on the LEDs were too short to reach the other side of the board so I had to wire through the board and then solder at both ends to get a connection. At this point, I was beginning to get somewhat perplexed as, my hastily built PCB test board was working correctly but the carefully wired and set up switch board wasn't and I didn't know why. This wasn't rocket science either, just some very basic connections that should just work. I eventually came to the conclusion that the PCB was compromised and no longer to be trusted. This was a shame, but I still had my original test built on the other board so I wired that in. Success, all the switches worked and two LEDs did. But not the other two. So I began yet another round of checking voltages. I soon sussed out that the two failing LEDs were simply not getting enough power to light them so I traced back to the board and then discovered that my eyesight had let me down. The resisters on the test board were wrong. Only two of course but enough to stop their associated LEDs from lighting. They had been tested on very small low needs LEDs and now I was asking them to power larger and higher needs LEDs, they couldn't cope. So, out with the soldering iron again, swap them for the correct value and, finally, all is working. Now I have to shorten all the wires between the two boards and fit the whole thing into my bench.

It's mounting up..........

With 60 countries and over 2000 individual visitors to the site it seems a good time to run over the philosophy of our open blogger. The idea was, and still is, that it would be used as an open source diary to compliment the various open source areas we cover. These being the Arduino micro controller boards and software and the Raspberry Pi computer and it's software. So far, the Raspi hasn't had too much of a look in as I have been following my plans for the Arduino somewhat single mind-idly  for the past six months. This has resulted in me learning quite a lot about digital electronics though which will be just as useful for the Raspi as the Arduino. I am, hopefully in the final stages of building the finished control unit for my mains switch this week and I have been documenting it with my camera for future publication. Next will be to produce an Arduino work alike to run the switches and a mains power supply for independence.

How about you though? Have you got anything to blog about? Are you prepared to publish it here? If you are then contact me via the comments at the bottom of this post.

I give in......

My attempt at creating a stand alone Arduino clone of my own has foundered slightly. Whilst the breadboard version worked really well, the hard wired one didn't. I have spotted a few obvious mistakes over the week but none of them have made any difference when rectified. Even more annoying, the test is a simple flash on pin 13 with a time delay of about one second. I can put a meter on the connections and it is registering the timer perfectly. The problem appears to be with the LED, except that the LED works fine elsewhere. I am beginning to lose it with this circuit. In fact, I have decided to go back to the drawing board and build the breadboard circuit up again. This time, I will extend the outputs to several LEDs and see how they affect the performance. In addition, I may put a regulator on the breadboard as well to be certain about the power capability of the whole unit.

All but one

of the UK orders have now arrived. He seems to have a genuine excuse as he has proof of posting. Equally, I have proof of non-arrival as all items are sent via the post room who keep a record of everything delivered. Anyway, he will chase Royal Mail from his end and I will keep an even closer watch from my end. The Hong Kong order should be here by the end of this week or the beginning of next week if past results are anything to go by. However, it wouldn't surprise me to hear that the Olympics held up all packages through Hong Kong as their Postal Service always has a ready excuse for non delivery. Fortunately, the trader who posted to me is well known to me and I trust them.

Rollin', Rollin', Rollin', Rawhide!

The components keep arriving but not the ones I'm waiting for. I have also noticed that the order to Hong Kong which is not due yet but will arrive pretty much on time and complete in all details is due in next week. All of the UK sourced components are trickling in and are now all later than promised on eBay. Three of the four UK suppliers have made some sort of mistake in the order and, either I have had to email them or they have found the problem themselves and sent an apology email. I'm not particularly annoyed by this, just puzzled by why British companies are able to get such a simple process wrong but a Chinese company gets it right every time. There are, of course, some UK suppliers who get it right every time (Thanks Bob) but very few in my own experience.

Houston, we have five volts!

Yes, it's true. The power board works a treat and produces the requisite five volts to power the controller. Next, I will have to build a slightly more powerful power unit in order to be able to run the LEDs and the relays. It would also be better to run the soldering tools with a triac switch but, for now, the relays will suffice. Whilst I am waiting for the correct strip board I am loath to do much else but I might build a controller on one of the special boards I bought.

Work

has begun on my mains powered switching system, the first of the transformers have arrived and been tested. They are exactly what I hoped for so next I will be checking out the bridge rectifier and voltage control electronics. The next job then will be to build a strip board version of the breadboard circuit and make it all work as one unit. You may be wondering why I am so keen on using mains for this particular job. In fact, not just mains but a home brew mains unit. The answer is very simple, this unit is intended to be built into the supply chain for my soldering irons, Piranha lights and screwdriver chargers. To do this and remain green, I want to have something that, when switched off, is completely isolated from it's power supply and doesn't need to be charged or new batteries added every so often. As I have more than one project in mind here, it would seem to be a good idea to manufacture my own system and build it into the various boxes instead of running it from a wall wart. There is also the fact that it should work out cheaper, I will be learning and it will be a lot more fun this way.