Brent Dekker / SRF08

Library for interfacing the SRF08 ultrasonic range sensor. Most functions of the SRF08 are covered, including interrupt-based waiting for the ranging process to finish

Dependents:   DISCO-F746NG_LCDTS_demo Srf08Test

/media/uploads/brentdekker/ultrasonic-range-finder-srf08.jpg

SRF08

Warning

Don't forget to add the pullup resistors from 5v to SDA and SCL!

Information on the SRF08 can be found here: http://www.robot-electronics.co.uk/htm/srf08tech.shtml

Example program

#include "mbed.h"
#include "SRF08.h"

Serial PC(USBTX, USBRX);       //Debug port to PC
SRF08 rangeMod1(p28, p27, 0xE4); //SRF08 ranging module 1
SRF08 rangeMod2(p28, p27, 0xE2); //SRF08 ranging module 2

int main() {
    PC.printf("Start ranging test \n");
    rangeMod1.setAddress(0xE4); //Factory default is 0xE0
    while(1) {
        rangeMod1.startRanging();
        while (!rangeMod1.rangingFinished() ) wait(0.01);
        int range1 = rangeMod1.getRange();
        int light1 = rangeMod1.getLightIntensity();
        rangeMod2.startRanging();
        while (!rangeMod2.rangingFinished() ) wait(0.01);
        int range2 = rangeMod2.getRange();
        PC.printf(" Range_1: %i", range1);
        PC.printf(" Range_2: %i", range2);
        PC.printf(" Light_1: %i", light1);
        PC.printf("\n");
    }
}

Library

Import library
SRF08 - SRF08 Class Reference

Public Member Functions

SRF08 (PinName SDA, PinName SCL, int i2cAddress)
Create a SRF08 object connected to the specified I2C pins and address.
void startRanging ()
Send the "Start ranging in cm" command via I2C.
bool rangingFinished ()
Checks if the module has finished ranging.
int getRange ()
Gets the measured range from the module.
int getLightIntensity ()
Gets the measured light intensity from the module.
void setRangeRegister (unsigned char rangeVal)
Sets the range register of the SRF08 for faster ranging.
void setMaxGainRegister (unsigned char gainVal)
Sets the max gain register of the SRF08 .
void setAddress (int i2cAddress)
Changes the I2C address of the SRF08 .

SRF08.h@0:4e0a8193b92e, 2012-07-05 (annotated)

Committer:
brentdekker
Date:
Thu Jul 05 09:53:18 2012 +0000
Revision:
0:4e0a8193b92e
Child:
1:76fb116fa28d
Version in which all functions of SRF08 are covered;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
brentdekker 0:4e0a8193b92e 1
brentdekker 0:4e0a8193b92e 2 /*
brentdekker 0:4e0a8193b92e 3 Copyright (c) 2010 Chris Styles (chris dot styles at mbed dot org)
brentdekker 0:4e0a8193b92e 4
brentdekker 0:4e0a8193b92e 5 Permission is hereby granted, free of charge, to any person obtaining a copy
brentdekker 0:4e0a8193b92e 6 of this software and associated documentation files (the "Software"), to deal
brentdekker 0:4e0a8193b92e 7 in the Software without restriction, including without limitation the rights
brentdekker 0:4e0a8193b92e 8 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
brentdekker 0:4e0a8193b92e 9 copies of the Software, and to permit persons to whom the Software is
brentdekker 0:4e0a8193b92e 10 furnished to do so, subject to the following conditions:
brentdekker 0:4e0a8193b92e 11
brentdekker 0:4e0a8193b92e 12 The above copyright notice and this permission notice shall be included in
brentdekker 0:4e0a8193b92e 13 all copies or substantial portions of the Software.
brentdekker 0:4e0a8193b92e 14
brentdekker 0:4e0a8193b92e 15 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
brentdekker 0:4e0a8193b92e 16 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
brentdekker 0:4e0a8193b92e 17 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
brentdekker 0:4e0a8193b92e 18 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
brentdekker 0:4e0a8193b92e 19 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
brentdekker 0:4e0a8193b92e 20 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
brentdekker 0:4e0a8193b92e 21 THE SOFTWARE.
brentdekker 0:4e0a8193b92e 22 */
brentdekker 0:4e0a8193b92e 23
brentdekker 0:4e0a8193b92e 24 #ifndef SRF08_H
brentdekker 0:4e0a8193b92e 25 #define SRF08_H
brentdekker 0:4e0a8193b92e 26
brentdekker 0:4e0a8193b92e 27 #include "mbed.h"
brentdekker 0:4e0a8193b92e 28
brentdekker 0:4e0a8193b92e 29 /*
brentdekker 0:4e0a8193b92e 30 * The SRF08 is an Ultrasonic range finder, with an I2C interface that allows the measurement to be read directly in centimetres
brentdekker 0:4e0a8193b92e 31 */
brentdekker 0:4e0a8193b92e 32 class SRF08 {
brentdekker 0:4e0a8193b92e 33
brentdekker 0:4e0a8193b92e 34 public:
brentdekker 0:4e0a8193b92e 35
brentdekker 0:4e0a8193b92e 36 /*
brentdekker 0:4e0a8193b92e 37 * Constructor: SRF08
brentdekker 0:4e0a8193b92e 38 * Args: PinName sda: Data pin of I2C bus to which module is connected
brentdekker 0:4e0a8193b92e 39 * PinName scl: Clock pin of I2C bus to which module is connected
brentdekker 0:4e0a8193b92e 40 * int addr: address of module on the I2C bus
brentdekker 0:4e0a8193b92e 41 * Returns: void
brentdekker 0:4e0a8193b92e 42 * Description: Creates an instance of the SRF08 to communicate with a sRF08 module
brentdekker 0:4e0a8193b92e 43 */
brentdekker 0:4e0a8193b92e 44 SRF08(PinName sda, PinName scl, int addr);
brentdekker 0:4e0a8193b92e 45
brentdekker 0:4e0a8193b92e 46 /*
brentdekker 0:4e0a8193b92e 47 * Destructor: ~SRF08
brentdekker 0:4e0a8193b92e 48 * Args: void
brentdekker 0:4e0a8193b92e 49 * Returns: void
brentdekker 0:4e0a8193b92e 50 * Description: Destroys instance of SRF08 class
brentdekker 0:4e0a8193b92e 51 */
brentdekker 0:4e0a8193b92e 52 ~SRF08();
brentdekker 0:4e0a8193b92e 53
brentdekker 0:4e0a8193b92e 54 /*
brentdekker 0:4e0a8193b92e 55 * Function: readRange
brentdekker 0:4e0a8193b92e 56 * Args: void
brentdekker 0:4e0a8193b92e 57 * Returns: int range
brentdekker 0:4e0a8193b92e 58 * Description: Reads the range register and converts it to a usable value
brentdekker 0:4e0a8193b92e 59 */
brentdekker 0:4e0a8193b92e 60 int read();
brentdekker 0:4e0a8193b92e 61
brentdekker 0:4e0a8193b92e 62 /*
brentdekker 0:4e0a8193b92e 63 * Function: readLightIntensity
brentdekker 0:4e0a8193b92e 64 * Args: void
brentdekker 0:4e0a8193b92e 65 * Returns: int lightIntensity
brentdekker 0:4e0a8193b92e 66 * Description: Reads the lightIntensity from the module
brentdekker 0:4e0a8193b92e 67 */
brentdekker 0:4e0a8193b92e 68 int readLightIntensity();
brentdekker 0:4e0a8193b92e 69
brentdekker 0:4e0a8193b92e 70 /*
brentdekker 0:4e0a8193b92e 71 * Function: setRangeRegister
brentdekker 0:4e0a8193b92e 72 * Args: rangeVal
brentdekker 0:4e0a8193b92e 73 * Returns: void
brentdekker 0:4e0a8193b92e 74 * Description: Sets the maximum range for which the module waits for an echo
brentdekker 0:4e0a8193b92e 75 * The range is ((rangeVal x 43mm) + 43mm)
brentdekker 0:4e0a8193b92e 76 * The max range is about six meters
brentdekker 0:4e0a8193b92e 77 */
brentdekker 0:4e0a8193b92e 78 void setRangeRegister(char rangeVal);
brentdekker 0:4e0a8193b92e 79
brentdekker 0:4e0a8193b92e 80 /*
brentdekker 0:4e0a8193b92e 81 * Function: setAddress
brentdekker 0:4e0a8193b92e 82 * Args: address
brentdekker 0:4e0a8193b92e 83 * Returns: void
brentdekker 0:4e0a8193b92e 84 * Description: Sets the address of the module on the I2C bus. The factory default address is 0x0E (224)
brentdekker 0:4e0a8193b92e 85 * The address can have the following values:
brentdekker 0:4e0a8193b92e 86 * E0 | E2 | E4 | E6 ... FC | FE
brentdekker 0:4e0a8193b92e 87 */
brentdekker 0:4e0a8193b92e 88 void setAddress(char address);
brentdekker 0:4e0a8193b92e 89
brentdekker 0:4e0a8193b92e 90 private:
brentdekker 0:4e0a8193b92e 91 I2C m_i2c;
brentdekker 0:4e0a8193b92e 92 int m_addr;
brentdekker 0:4e0a8193b92e 93
brentdekker 0:4e0a8193b92e 94 };
brentdekker 0:4e0a8193b92e 95
brentdekker 0:4e0a8193b92e 96 #endif