c_meyer/pxt-calliope
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

support for max-duration in pulse-in

Browse Source
This commit is contained in:
Peli de Halleux
2016-08-17 11:35:54 -07:00
parent 8e811b913e
commit 9f31637000
4 changed files with 20 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
libs/microbit/pins.cpp
View File

@@ -169,20 +169,28 @@ namespace pins {
* Returns the duration of a pulse in microseconds
* @param name the pin which measures the pulse
* @param value the value of the pulse (default high)
* @param maximum duration in micro-seconds
*/
//% blockId="pins_pulse_in" block="pulse in (µs)|pin %name"
//% blockId="pins_pulse_in" block="pulse in (µs)|pin %name|pulsed %value"
//% weight=20
int pulseIn(DigitalPin name, PulseValue value) {
int pulseIn(DigitalPin name, PulseValue value, int maxDuration = 2000000) {
MicroBitPin* pin = getPin((int)name);
if (!pin) return 0;
int pulse = value == PulseValue::High ? 1 : 0;
while(pin->getDigitalValue() != pulse);
uint64_t tick = system_timer_current_time_us();
uint64_t maxd = (uint64_t)maxDuration;
while(pin->getDigitalValue() != pulse) {
if(system_timer_current_time_us() - tick > maxd)
return 0;
}
uint64_t start = system_timer_current_time_us();
while(pin->getDigitalValue() == pulse);
while(pin->getDigitalValue() == pulse) {
if(system_timer_current_time_us() - tick > maxd)
return 0;
}
uint64_t end = system_timer_current_time_us();
return end - start;
}