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The Cottage The cottage has been extended at the back to house the electronics and below to hide the mechanism. The front window has a new frame to show off the LED temperature indicator.     Mechanics The mechanism is a double ended Watt's linkage which gives an approximately linear movement for the figures. This is connected by a sprung stainless steel wire to the micro servo. Diametrically polarised magnets ensure that the characters are always pointing in the right direction. ...
The cottage was disassembled so that the base could be painted matt black. This is an old magician's trick to draw the eye away from the base and hidden mechanism underneath. The top panel electronics were also put together with another bit of stripboard, a couple of buttons and a 3 way connector. This was then glued to the top panel using some blobs of Sugru, of course it's best if you can avoid gluing your electronics into the product as it makes the whole thing harder to service. Given ...
Cost Analysis As well as the components kindly provided by Element14, Atmel and Infineon there were several additional components purchased for this project. These were bought as the project progressed or were already in the spares drawer. Where the original supplier was not known the costs were estimated based on current prices. Where more components were purchased than needed the costs were pro-rated. I've tried to include absolutely everything but it is possible that something was missed.  ...
The Enchanted Cottage build has been a multi faceted project with electronics, micro-controllers, embedded Linux, woodwork, 3D printing and general assembly challenges. To give you a better idea about how I worked on the project I've made a list of all the tools I used. Tools and equipment There was a wide variety of tools used for the project. Nothing was bought specifically for the project but a couple of things were made. The Robox 3D printer came in handy as it allowed parts such as the top ...
Following lots of rude interruptions from the Wolf, Hans decided the Arduino Yún's security needed beefing up. After a bit of reading Hans realised that this could be a 16 week design challenge in it's own right.   Hans' plan of action for the lock down was as follows:   Users and passwords Handle brute force attacks Remove unused functions Apply principle of least privilege   Passwords Hans had already changed the default root password to something unique but realised ...
Whilst Hans was coding Matilda was fine tuning the mechanism and finishing the housing. When the magnet housings had been tested their positions had put Hans and Matilda a bit far back into the cottage. The magnet carriers were redesigned so that the holes were towards one end, that would move the positions forward by about 7mm and the coverings for the holes turned out not to be needed so those were removed to reduce printing time. Due to their simple design and shape they printed first time ...
Disable the bridge As mentioned in previous episodes the plan was to remove the bridge as that provided much more functionality than it needed to and it also provided root access to the Linino side from the Arduino code. Hans thought would replace it with direct serial communications between the two CPUs.   To stop the bridge /etc/inittab is edited to disable the connection of the console to the serial port ttyATH0, the Yún needs to be rebooted after this change.   ::sysinit:/ ...
When I was making the Topsy Turvy Clock I created a non blocking delay class so that the Arduino could be doing other things whilst waiting for a timeout. This avoids the use of the delay function which otherwise "blocks" the operation until the timeout is completed. I realised that this same technique could be used to control the flashing of the RGB LED. This will need to be expanded to handle the colour cycling which will indicate that the Wifi settings need configuring.   Code: https:// ...
The bridge Hans had been spending too much time inside coding. So this morning he went for a wander down by the stream. As he neared the town he saw the new bridge that had been put in so that the children could cross the stream to get to the school. The bridge was made of iron and had gates so that cattle did not wander across. There was a solar powered telephone box so that the kids could make calls and send emails and notice board so that the school could leave important bulletins for them to ...
A trip up the fell Matilda looked serious, she was dressed in a boiler suit, boots and a hard hat, she was leaning on a pickaxe. "Do you remember that watch my father gave you as a wedding present?", Hans nodded and took it out of his waistcoat pocket. "Put it in the drawer", Matilda commanded "and your reading glasses". Hans put the items in the drawer. "Put on your gear and meet me out front". Hans put on his boiler suit, hat and boots and headed out. He was met by Matilda and Farmer Hogg who ...
Some fantastic examples from model making company Pantograph, I particularly like the binary type writer   www.spoon-tamago.com/2015/06/08/pantograph-imagines-gadgets-from-a-parallel-world/ ...
Matilda does not see the light When Matilda tested the temperature status LED it was clear that it was not going to be visible from outside the cottage. The dark cottage interior sapped away the struggling coloured lumens. However, Matilda spotted that the LED was positioned right opposite the fake painted window on the front of the cottage. If that could be replaced with a real window then the LED would be clearly visible. Now some people when thinking about new windows would be looking at c ...
Whilst Matilda worked on the LEDs and top panel, Hans finished off the circuits for the MOSFET power switch and connectors.   Circuit Explanation  A MOSFET is used as a low side switch to turn the power to the servo, RGB LED controller board and humidity sensor. This is connected to the Arduino output with a few extra components from the Arduino Workshop Kit.   The gate of the MOSFET effectively acts like a big capacitor and for a short period before the transistor turns on it c ...
The Crystal Cave  It had been a hard week so a trip to the Adam and Eve Inn was in order. Hans and Matilda sat next to the dwarves who for once were not having an argument. The dwarves had recently discovered a new cave lined with amethyst and citrine crystals, they discovered a strange phenomenon that happened on a full moon. Tonight was a full moon so Hans and Matilda were invited to see. They were given hard hats with lights and headed off through the forest to the mine. As they journey ...
No volts When Hans wired up the comparator circuit he could not get the output to go high. He swapped out the sensor with a simple voltage divider but still nothing. Thinking that he'd got a duff component he tried another, still the output stayed on 0v. The data sheet provided a clue, the output needed a pull up resistor, it could only act as a current sink. The resistor was added and the voltage divider circuit behaved as expected, switching from low to high as the trim pot was adjusted. &# ...