notes.txt

How to adpcm:
http://www.atmel.com/images/doc2572.pdf

Onliners:
http://canonical.org/~kragen/sw/inexorable-misc/onelinermusic.html

AVR Instruction set:
http://www.atmel.com/images/Atmel-0856-AVR-Instruction-Set-Manual.pdf


3V Button Battery
* 20mm CR2032
  - Nominal Discharge Current (mA) 0.2

* 12mm CR1225 
  - Standard Discharge Current 0,1 mA
  - Max. Cont. Discharge Current 1,0 mA


NOTE:

How to produce FM frequency is at page 85 of ATTiny datasheet.

In summary:
* We will use clk_pck = PCK for our signal.
* This saturates at 85MHz worst case - thus, we should aim slightly below this.
* RC Oscillator runs at 8MHz by default, but can be boosted to 16-24MHz by adjusting OSCCAL
* Based on LSM bit, clk_pck runs at either 4x or 8x of RC Oscillator
* CPU runs at either RC Oscillator or 2x RC Oscillator 

European FM radio starts at 87,5MHz, so we will have to stretch the 85MHz a bit to reach it

Algorithm:
OSCCAL *= 2.75 (Set RC Oscillator to 22MHz)
LSM = 1 (Set 8xPLL input to half of RC oscillator; result is x4 and 88MHz)
PLLE = 1 (enable PLL)
assert(PLOCK==1);