Thursday, 30 May 2013

Radio playing

Lifes been a bit hectic of late but managed to get one little thing done this week which was use one of these very cheap (6quid delivered from shenzen) dab/freeview dongles and get it setup with alternate drivers so it becomes a software defined radio. I got it working with SDR# following these instructions  here . I also worked out how to get it to send audio to another piece of software called  fldigi which is a software modem capable of decoding audio from a radio meaning if I get a decent homebrew antenna built I should be able to decode satellite far for less than a tenner! Also got my test for my foundation licence next week...gotta do a bit of reading!

Saturday, 11 May 2013

Diy arduino clones

Got a bit of time today and managed to get a diy arduino clone up and running which I'd been meaning to do for a while. There is an excellent guide and set of instructions here at the ShrimpingIT page, those people are amazing and run loads of workshops helping people to build there own cheap diy arduino clones aka "shrimps" and they even sell kits to make them and projects to build onto them.

So an arduino has a big old atmega chip on it that contains the bootloader and is where you flash your code too and to make the atmega chip work all thats needed is a resistor, a 16mhz oscillator and 2 or 3 capacitors, however you have to have the ability to flash your sketch/code to it...on an arduino the ftdi chip and usb socket etc are all added on board as is a regulated power supply etc...but on a diy clone so long as you can flash your code to it you don't need all the usb/ftdi side of things to run in whatever your project is.

So (from the shrimpingIT site) what you need is a CP2102 usb - uart board which is a usb to serial converter and with this you can program your duinoclone. I needed to connect to a pin that wasn't connected on my cp2102 so I added these 2 rows of header pins to mine meaning that I could access the pin on the breadboard and that the whole cp2102 would fix into the pin slots on the board holding it steady.

I'm really pleased I managed to get this going...I reckon the components to make this cost about 3.50GBP and the cp2102 was a couple of quid of ebay...compared to official arduino uno's going for anywhere between 12 and 20 quid it's a great saving. However the other reason that this interests me is that if I make designs from prototypes done with an arduino I can design and build complete PCB boards rather than adding a shield to an arduino giving me more flexibility in layout and components etc.

Massive props to shrimpingIT once again.