Merge pull request zhaolei#9 from pctj101/fixPwmTone

Fix duty cycle to half period

build

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 # check if sudo is required and save the result as ${PFX}:
 [[ ${EUID} -ne 0 ]] && PFX='sudo ' || PFX=''

examples/cli_song.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+# Example of how to export PWM Pin and play tones via CLI
+
+export WIRINGPI_DEBUG=true 
+export WIRINGPI_CODES=true 
+GPIO=../gpio/gpio
+
+$GPIO export 1 out
+$GPIO mode 1 pwm
+$GPIO pwmTone 1 1033
+
+for i in 262 523 220 440 233 466 0 0 262 523 220 440 233 466 0 0 175 349 147 294 156 311 0 0 175 349 147 294 156 311 0 0 311 277 294 277 311 311 208 196 277 262 370 349 165 466 440 415 311 247 233 220 208 0 0 0 ; do 
+	$GPIO pwmTone 1 $i;
+	sleep 0.15;
+done

wiringPi/wiringPi.c

@@ -2317,9 +2317,9 @@ void pwmToneWrite (int pin, int freq)
     pwmWrite (pin, 0) ;             // Off
   else
   {
-    range = 600000 / freq ;
+    range = 200000 / freq ;
     pwmSetRange (range) ;
-    pwmWrite    (pin, freq / 2) ;
+    pwmWrite    (pin, range / 2) ;
   }
 }