sonar.h

Go to the source code for sonar.h

Includes

• #include "gpio.h"
• #include "time.h"

Functions

• InitializeSonar
• SonarRead
• SonarBackgroundRead
• SonarReadContinuouslyUS
• SonarReadContinuously

Function Documention

---

InitializeSonar

Initializes a sonar on a pair of pin

tSonar *InitializeSonar(tPin trigger, tPin echo);

Parameters:

• trigger Pin plugged into the sonar's tigger line
• echo Pin plugged into the sonar's echo line

Returns:

• Pointer to an initialized tSonar, can be used by the SonarRead functions

---

SonarRead

Returns the distance measured from the sonar

float SonarRead(tSonar *snr);

Parameters:

• snr Pointer to an initialized tSonar, returned by InitializeSonar

Returns:

• The distance measured as a percentage of maximum range of the sonar. If no response is detected, a value of infinity is returned.

Notes:

• if the sonar is not continously reading, then the function will busy wait for the results

---

SonarBackgroundRead

Sets up an sonar to be run in the background

void SonarBackgroundRead(tSonar *snr, tCallback callback, void *data);

Parameters:

• snr Pointer to an initialized tSonar, returned by InitializeSonar
• callback Function called the next time the sonar read completes, in which a call to SonarRead will return with the newly obtained value immediately
• data Argument sent to the provided callback function whenever it is called

---

SonarReadContinuouslyUS

Sets up an sonar to read indefinitly

void SonarReadContinuouslyUS(tSonar *snr, tTime us);

Parameters:

• snr Pointer to an initialized tSonar, returned by InitializeSonar
• us Time between calls to read the sonar in micro seconds

Notes:

• Any following calls to SonarRead will return the most recent value
• If the passed time between calls is less than the time it takes for the sonar read to complete, the sonar will fire as fast as possible without overlap

---

SonarReadContinuously

Sets up an sonar to read indefinitly

void SonarReadContinuously(tSonar *snr, float s);

Parameters:

• snr Pointer to an initialized tSonar, returned by InitializeSonar
• s Time between calls to read the sonar in seconds

Notes:

• Any following calls to SonarRead will return the most recent value
• If the passed time between calls is less than the time it takes for the sonar read to complete, the sonar will fire as fast as possible without overlap

---