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Merge pull request #465 from stevstrong/patch-12 

Increase tone resolution
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Roger Clark 2018-03-28 13:27:30 +11:00 committed by GitHub
parent c85d83b1f9 e76e8adb52
commit 3521747556
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1 changed files with 2 additions and 2 deletions
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STM32F1/cores/maple/tone.cpp
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@ -60,7 +60,7 @@ uint8_t tone_ntimer = TONE_TIMER; // timer used to generate freque
bool tone_state = true; // last pin state for toggling
short tone_pin = -1; // pin for outputting sound
short tone_freq = 444; // tone frequency (0=pause)
volatile uint32_t tone_nhw = 0; // tone duration in number of half waves
volatile uint32_t tone_nhw = 0; // tone duration in number of half waves
uint16_t tone_tcount = 0; // time between handler calls in 1/36 usec
uint16_t tone_ncount = 0; // handler call between toggling
uint16_t tone_n = 0; // remaining handler calls before toggling
@ -151,7 +151,7 @@ void tone(uint32_t pin, uint32_t freq, uint32_t duration) {
tone_ncount = tone_n = (count>>16)+1; // number of 16-bit count chunk
tone_tcount = count/tone_ncount; // size of count chunk
if(duration > 0) // number of half waves to be generated
tone_nhw = ((duration*freq)/1000)<<1;
tone_nhw = duration*freq*2/1000;
else // no duration specified, continuous sound until noTone() called
tone_nhw = 0;