torsdag den 21. februar 2013

Plug-in warning with embedded SVG files

Quick SVG-tip:

If you get a plug-in warning in Firefox or your Google Chrome browser immediately takes to downloading an embedded SVG file in your HTML-page, this is because you're referencing the SVG-file locally, i.e.

<embed src="../images/info_icon.svg" type="image/svg+xml" />

... as opposed to absolutely:

<embed src="http://your_web_server/studentExchange/images/info_icon.svg" type="image/svg+xml" />

If you reference the SVG file absolutely, the plug-in warning will go away.

Hooking up the UsbTinyISP to an Arduino Uno

The UsbTinyISP is a micro-controller flashing interface, which will allow you to flash the code on various Atmel micro-processors. The below image references how to hook it up to an Arduino Uno development board - I couldn't find a suitable reference-image so I thought I'd provide it.

So when in doubt, turn the boards the same way as in the image and look for the red strand of the wire.

Then, for flashing an Arduino bootloader to the chip, it's a simple matter of selecting the UsbTinyISP in the Arduino (it's in the 'tools' menu) and clicking 'burn bootloader' (also in the 'tools' menu).

Remember - the UsbTinyISP must be installed with the appropriate drivers and it's only the UsbTinyISP that should be connected to the PC - not the Arduino Uno.

The Arduino IDE runs a version of the AVRDude-tool and will also take care of any setting of fuses on the micro-controller. Burning the bootloader takes about a minute or so, beyond which you can program the micro-controller in the IDE and then yank it from the Uno development board and put it in your own project.

Happy flashing!

Hooking up a microcontroller to the AVR Dragon

The AVR Dragon is a development board for Atmel micro-controllers, used in conjunction with Atmel's AVR Studio.

In using this board it's not only necessary to add a micro-controller to the board, but this micro-controller must also be hooked up to the board's connectors (one is expected to solder pins to the board's through-holes) or the AVR Studio will not be able to see the micro-controller.

These are the connections that must be made with jumper wires:

I recommend Derek Molloy's terrific video on the subject.