arduino stuffs
Diffstat (limited to 'libraries/NewPing/examples/NewPingEventTimer/NewPingEventTimer.pde')
| -rw-r--r-- | libraries/NewPing/examples/NewPingEventTimer/NewPingEventTimer.pde | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/libraries/NewPing/examples/NewPingEventTimer/NewPingEventTimer.pde b/libraries/NewPing/examples/NewPingEventTimer/NewPingEventTimer.pde new file mode 100644 index 0000000..b0aa119 --- /dev/null +++ b/libraries/NewPing/examples/NewPingEventTimer/NewPingEventTimer.pde @@ -0,0 +1,46 @@ +// --------------------------------------------------------------------------- +// This example shows how to use NewPing's ping_timer method which uses the Timer2 interrupt to get the +// ping time. The advantage of using this method over the standard ping method is that it permits a more +// event-driven sketch which allows you to appear to do two things at once. An example would be to ping +// an ultrasonic sensor for a possible collision while at the same time navigating. This allows a +// properly developed sketch to multitask. Be aware that because the ping_timer method uses Timer2, +// other features or libraries that also use Timer2 would be effected. For example, the PWM function on +// pins 3 & 11 on Arduino Uno (pins 9 and 10 on Arduino Mega) and the Tone library. Note, only the PWM +// functionality of the pins is lost (as they use Timer2 to do PWM), the pins are still available to use. +// NOTE: For Teensy/Leonardo (ATmega32U4) the library uses Timer4 instead of Timer2. +// --------------------------------------------------------------------------- +#include <NewPing.h> + +#define TRIGGER_PIN 12 // Arduino pin tied to trigger pin on ping sensor. +#define ECHO_PIN 11 // Arduino pin tied to echo pin on ping sensor. +#define MAX_DISTANCE 200 // Maximum distance we want to ping for (in centimeters). Maximum sensor distance is rated at 400-500cm. + +NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); // NewPing setup of pins and maximum distance. + +unsigned int pingSpeed = 50; // How frequently are we going to send out a ping (in milliseconds). 50ms would be 20 times a second. +unsigned long pingTimer; // Holds the next ping time. + +void setup() { + Serial.begin(115200); // Open serial monitor at 115200 baud to see ping results. + pingTimer = millis(); // Start now. +} + +void loop() { + // Notice how there's no delays in this sketch to allow you to do other processing in-line while doing distance pings. + if (millis() >= pingTimer) { // pingSpeed milliseconds since last ping, do another ping. + pingTimer += pingSpeed; // Set the next ping time. + sonar.ping_timer(echoCheck); // Send out the ping, calls "echoCheck" function every 24uS where you can check the ping status. + } + // Do other stuff here, really. Think of it as multi-tasking. +} + +void echoCheck() { // Timer2 interrupt calls this function every 24uS where you can check the ping status. + // Don't do anything here! + if (sonar.check_timer()) { // This is how you check to see if the ping was received. + // Here's where you can add code. + Serial.print("Ping: "); + Serial.print(sonar.ping_result / US_ROUNDTRIP_CM); // Ping returned, uS result in ping_result, convert to cm with US_ROUNDTRIP_CM. + Serial.println("cm"); + } + // Don't do anything here! +}
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