Hey,
I'm experiencing problems using a timer twice in a sequence. I use this two functions for the timer [...]
Update: Ok, this issue is solved, I just forgot to clear the TOF flag between both timers. That made the 2nd. timer run erratic.
But I have another question of understanding:
void irpulse(){ int run; TSC_TSTOP=1; TSC_TRST=1; TSC_PS0=0; TSC_PS1=0; TSC_PS2=0; TMOD=45; TCH0=32768; TSC0_MS0A=0; TSC0_MS0B=1; TSC0_TOV0=1; TSC0_ELS0B=1; TSC0_ELS0A=0; TSC_TSTOP=0; for (run=0; run<57; run++){ while(TSC_TOF == 0); } TSC_TOF=0; TSC_TSTOP=1; TSC_TRST=1; LEDir=0; }
This function generates an approx. 32kHz 570µs width burst for infrared transmitter by using the PWM generation functionality. One single pulse/pause is 30µs, so a total of 19 pulses equals to the 570µs. 19 cycles means 38 phase changes (toggles on overflow). However if I write:
for (run=0; run<38; run++){ while(TSC_TOF == 0); }
I'll get only 12 pulses on my scope. I try-and-error-tune it to run<57 and I'll get an exact count of 19 pulses - a precise and stable burst of 570µs width. That works fine for me, but I want to understand why this routine does not work as expected.
Best regards
Holger
Last edited by Holger Keil
