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-- Title: Test program for hardware (built-in) PWM. Plays sound
-- Author: Sebastien Lelong, Copyright (c) 2008, all rights reserved.
-- Adapted-by:
-- Compiler: >=2.4i
-- Revision: $Revision$
-- 
-- This file is part of jallib (http://jallib.googlecode.com)
-- Released under the BSD license (http://www.opensource.org/licenses/bsd-license.php)
--
-- Description: this sample show how to use PWM with a constant duty cycle and 
-- a variable frequency. It plays a "nice" melody (connect a small piezzo)
-- Frequencies from 0 to 100_000Hz are played. At the beginning, no sound will come
-- the buzzer, because frequency is too low (no valid combination of PR2/T2CON)
--
-- 
--
--
-- This file has been generated on Sun Feb  8 11:05:56 2009, from:
--    * board: board_16f88_sl.jal
--    * test : test_pwm_sound.jal
--


;@jallib section chipdef
-- chip setup
include 16f88

;-- 
-- We'll use internal oscillator. It work @ 8MHz
pragma target clock		8_000_000
pragma target OSC		INTOSC_NOCLKOUT
-- Specify no postscaler, ie. really runs @8MHz
OSCCON_IRCF = 0b_111
pragma target WDT		   disabled       -- no watchdog
pragma target LVP		   disabled       -- no low-voltage programming
pragma target CCP1MUX	   RB0            -- ccp1 pin on B0
pragma        bootloader   long_start     -- for TinyBootloader

;@jallib section ccp
-- ccp setup
var volatile bit pin_ccp1_direction is pin_b0_direction

enable_digital_io()

-- Configure PWM
pin_ccp1_direction = output
include pwm_hardware
-- Let's go !!!
pwm1_on()


var dword counter = 0
forever loop
   
   for 100_000 using counter loop
      pwm_set_frequency(counter)
      -- Setting @50% gives max volume
      -- must be re-computed each time the frequency
      -- changes, because it depends on PR2 value
      pwm1_set_percent_dutycycle(50)
   end loop
   
end loop