This one shows you how to :
1)Build a very cheap device that plays an 8-bit version of Still Alive from Portal
2)On the same hardware , but with a different chip , play the "radio tune"
Here are both projects , in the same video (I hope the video quality does not affect how this entry is rated.I filmed it with a phone camera) :
Move on to the next step for the parts list for each of the two projects
Step 1: Parts List
What do you need ?
You need to know how to program AVR microcontrollers
Here's the parts list :
1)A 16 MHz crystal oscillator
2)A 75 Ohm (Or something around that value) resistor
3)An audio jack connector , so you can connect the device to speakers
4)A 7805 5Volt voltage regulator
5)For the 8 bit version of still alive you will need an ATMega16.For the second project , you will need an ATMega644.The parts above are common for both projects.
And the tools list :
1)An AVR programmer
...and that's it.You really don't need any tools , IF you have a breadboard and some wires .
But in case you don't have a breadboard , grab a perfboard , a 40 pin DIP socket for the microcontroller , a soldering gun , and solder everything on the board,according to the schematic (Which is in the next step).
Step 2: Build the Beast
The schematic is common , for both projects.You will only need to change the chip.
For the 8 bit version of Still Alive , use ATMega16
For the radio tune , use ATMega644
Both chips have the same pinout , so in case you are soldering everything to a perfboard , if you want it to ,make both projects on the same board, use a 40 pin DIP socket and swap the chips when you want.
The schematic is attached to this step.
Here are the firmware files for the AVRs:
1)8-bit Still Alive , for ATMega16 : https://sourceforge.net/projects/avrsa/files/StillAliveATMega16.hex/download
2)The radio tune , for ATMega644 : https://sourceforge.net/projects/avrsa/files/RadioTuneATMega644.hex/download
Step 3: Troubleshooting
If the song sounds very slowed down compared to the video
Are you sure you configured your AVR to run on an external crystal ? Try to remove the 16 MHz oscillator.If it still works , it means it's running on the internal 8 MHz oscilaltor , and that's why it is so slow. Configure the fuse bits for External Crystal Oscillator (Leave all CKSEL bits unprogrammed).
Step 4: This Was a Triumph !
Anyway , I hope you liked this instructable :)