arduino stuffs
Diffstat (limited to 'libraries/NewPing/examples/NewPingTimerMedian/NewPingTimerMedian.pde')
| -rw-r--r-- | libraries/NewPing/examples/NewPingTimerMedian/NewPingTimerMedian.pde | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/libraries/NewPing/examples/NewPingTimerMedian/NewPingTimerMedian.pde b/libraries/NewPing/examples/NewPingTimerMedian/NewPingTimerMedian.pde new file mode 100644 index 0000000..5908f58 --- /dev/null +++ b/libraries/NewPing/examples/NewPingTimerMedian/NewPingTimerMedian.pde @@ -0,0 +1,60 @@ +// --------------------------------------------------------------------------- +// Calculate a ping median using the ping_timer() method. +// --------------------------------------------------------------------------- + +#include <NewPing.h> + +#define ITERATIONS 5 // Number of iterations. +#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 (in cm) to ping. +#define PING_INTERVAL 33 // Milliseconds between sensor pings (29ms is about the min to avoid cross-sensor echo). + +unsigned long pingTimer[ITERATIONS]; // Holds the times when the next ping should happen for each iteration. +unsigned int cm[ITERATIONS]; // Where the ping distances are stored. +uint8_t currentIteration = 0; // Keeps track of iteration step. + +NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); // NewPing setup of pins and maximum distance. + +void setup() { + Serial.begin(115200); + pingTimer[0] = millis() + 75; // First ping starts at 75ms, gives time for the Arduino to chill before starting. + for (uint8_t i = 1; i < ITERATIONS; i++) // Set the starting time for each iteration. + pingTimer[i] = pingTimer[i - 1] + PING_INTERVAL; +} + +void loop() { + for (uint8_t i = 0; i < ITERATIONS; i++) { // Loop through all the iterations. + if (millis() >= pingTimer[i]) { // Is it this iteration's time to ping? + pingTimer[i] += PING_INTERVAL * ITERATIONS; // Set next time this sensor will be pinged. + if (i == 0 && currentIteration == ITERATIONS - 1) oneSensorCycle(); // Sensor ping cycle complete, do something with the results. + sonar.timer_stop(); // Make sure previous timer is canceled before starting a new ping (insurance). + currentIteration = i; // Sensor being accessed. + cm[currentIteration] = 0; // Make distance zero in case there's no ping echo for this iteration. + sonar.ping_timer(echoCheck); // Do the ping (processing continues, interrupt will call echoCheck to look for echo). + } + } + // Other code that *DOESN'T* analyze ping results can go here. +} + +void echoCheck() { // If ping received, set the sensor distance to array. + if (sonar.check_timer()) + cm[currentIteration] = sonar.ping_result / US_ROUNDTRIP_CM; +} + +void oneSensorCycle() { // All iterations complete, calculate the median. + unsigned int uS[ITERATIONS]; + uint8_t j, it = ITERATIONS; + uS[0] = NO_ECHO; + for (uint8_t i = 0; i < it; i++) { // Loop through iteration results. + if (cm[i] != NO_ECHO) { // Ping in range, include as part of median. + if (i > 0) { // Don't start sort till second ping. + for (j = i; j > 0 && uS[j - 1] < cm[i]; j--) // Insertion sort loop. + uS[j] = uS[j - 1]; // Shift ping array to correct position for sort insertion. + } else j = 0; // First ping is sort starting point. + uS[j] = cm[i]; // Add last ping to array in sorted position. + } else it--; // Ping out of range, skip and don't include as part of median. + } + Serial.print(uS[it >> 1]); + Serial.println("cm"); +}
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