altb_pmic / Mbed 2 deprecated Grove-UltrasonicRanger_Example

UltrasonicRanger_Example V1.0

Dependencies:   mbed RangeFinder

main.cpp@4:881e860d7de1, 2019-06-24 (annotated)

Committer:
pmic
Date:
Mon Jun 24 09:08:55 2019 +0000
Revision:
4:881e860d7de1
Parent:
3:4a2cd363c443
Child:
6:86943d1ed254
measure sensor 3 and 4. additionally include 20 Hz (former 50 Hz) parametrization.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
NickRyder 0:186bb2174995 1 /* Copyright (c) 2012 Nick Ryder, University of Oxford
NickRyder 0:186bb2174995 2 * nick.ryder@physics.ox.ac.uk
NickRyder 0:186bb2174995 3 *
NickRyder 0:186bb2174995 4 * MIT License
NickRyder 0:186bb2174995 5 *
pmic 3:4a2cd363c443 6 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
pmic 3:4a2cd363c443 7 * and associated documentation files (the "Software"), to deal in the Software without restriction,
pmic 3:4a2cd363c443 8 * including without limitation the rights to use, copy, modify, merge, publish, distribute,
pmic 3:4a2cd363c443 9 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
NickRyder 0:186bb2174995 10 * furnished to do so, subject to the following conditions:
NickRyder 0:186bb2174995 11 *
pmic 3:4a2cd363c443 12 * The above copyright notice and this permission notice shall be included in all copies or
NickRyder 0:186bb2174995 13 * substantial portions of the Software.
NickRyder 0:186bb2174995 14 *
pmic 3:4a2cd363c443 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
pmic 3:4a2cd363c443 16 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
pmic 3:4a2cd363c443 17 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
pmic 3:4a2cd363c443 18 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
NickRyder 0:186bb2174995 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
NickRyder 0:186bb2174995 20 */
NickRyder 0:186bb2174995 21
NickRyder 0:186bb2174995 22 #include "mbed.h"
pmic 3:4a2cd363c443 23 #include "RangeFinder.h"
pmic 3:4a2cd363c443 24 #include "IIR_filter.h"
NickRyder 0:186bb2174995 25
pmic 3:4a2cd363c443 26 /* Notes pmic 21.06.2019:
pmic 3:4a2cd363c443 27 - RangeFinder class extended with offset.
pmic 3:4a2cd363c443 28 - Static measurements have shown that the actual scaling is approx. 5782 (instead of 5800).
pmic 3:4a2cd363c443 29 - Avg. offset relative to top side of the board (pointing towards meas. direction) is 0.02 m
pmic 3:4a2cd363c443 30 - With 7000 mus (7 ms) timout time the max. measured distance is approx. 1.14 m. Theoreticaly
pmic 4:881e860d7de1 31 it is ( 0.007 s * 343.2 m/s )/2 = 1.201 m. If understood rigth the sensor does 8 measurements
pmic 3:4a2cd363c443 32 and takes the average. 1.201 - 1.14 m = 0.0612 m := 357 mus -> 357/8 = 44.6 ms / measurement
pmic 3:4a2cd363c443 33 - Min. distance is approx. 0.04 m (relative to top side board)
pmic 3:4a2cd363c443 34 - Using 50 Hz (Ts = 20 ms) the max. delay is 7 ms (@ max. dist. 1.14 m), there for 13 ms remain for other tasks
pmic 3:4a2cd363c443 35 (in real time implementation probably also possible to use 100 Hz)
pmic 3:4a2cd363c443 36 - read_m() returns -1 if object is not within certain range
pmic 3:4a2cd363c443 37 - sensor opening angle is approx. 15 deg
pmic 3:4a2cd363c443 38 */
pmic 3:4a2cd363c443 39
pmic 4:881e860d7de1 40 /* Notes pmic 24.06.2019:
pmic 4:881e860d7de1 41 - With 17500 mus (17.5 ms = 50/20*7000) timout time the max. measured distance is approx. 2.67 m. Theoreticaly
pmic 4:881e860d7de1 42 it is ( 0.0175 s * 343.2 m/s )/2 = 3.003 m.
pmic 4:881e860d7de1 43 - Using 20 Hz (Ts = 50 ms) the max. delay is 17500 ms (@ max. dist. 2.67 m), there for 32.5 ms remain for other tasks
pmic 4:881e860d7de1 44 */
pmic 4:881e860d7de1 45
pmic 3:4a2cd363c443 46 // PB_3 ist ist der 4te von unten rechts, aussen GND innen S16
NickRyder 0:186bb2174995 47
pmic 3:4a2cd363c443 48 /** Create a RangeFinder object
pmic 3:4a2cd363c443 49 * @param pin Digital I/O pin the range finder is connected to.
pmic 3:4a2cd363c443 50 * @param pulsetime Time of pulse to send to the rangefinder to trigger a measurement, in microseconds.
pmic 3:4a2cd363c443 51 * @param scale Scaling of the range finder's output pulse from microseconds to meters.
pmic 3:4a2cd363c443 52 * @param offset Offset of the range finder's output pulse to adjust absolut reference.
pmic 3:4a2cd363c443 53 * @param timeout Time to wait for a pulse from the range finder before giving up.
pmic 3:4a2cd363c443 54 * y = x/scale + offset
pmic 3:4a2cd363c443 55 */
pmic 4:881e860d7de1 56 // RangeFinder rf(PB_3, 10, 5782.0, 0.02, 7000); // 50 Hz parametrization
pmic 4:881e860d7de1 57 RangeFinder rf(PB_3, 10, 5782.0, 0.02, 17500); // 20 Hz parametrization
pmic 3:4a2cd363c443 58 float d = 0.0f;
pmic 3:4a2cd363c443 59
pmic 3:4a2cd363c443 60 Serial pc(SERIAL_TX, SERIAL_RX); // serial connection via USB - programmer
pmic 3:4a2cd363c443 61 InterruptIn Button(USER_BUTTON); // User Button
pmic 3:4a2cd363c443 62 Ticker LoopTimer; // interrupt for control loop
pmic 3:4a2cd363c443 63 Timer t; // timer to analyse Button
pmic 3:4a2cd363c443 64
pmic 3:4a2cd363c443 65 int k;
pmic 3:4a2cd363c443 66 bool doRun = false;
pmic 4:881e860d7de1 67 // float Ts = 0.02f; // sample time of main loop, 50 Hz
pmic 4:881e860d7de1 68 float Ts = 0.05f; // sample time of main loop, 20 Hz
pmic 3:4a2cd363c443 69
pmic 3:4a2cd363c443 70 IIR_filter pt1(0.2f, Ts, 1.0f);
pmic 3:4a2cd363c443 71 float df = 0.0f;
pmic 3:4a2cd363c443 72
pmic 3:4a2cd363c443 73 /*
pmic 3:4a2cd363c443 74 // Sensor 1
pmic 3:4a2cd363c443 75 float usGain = 0.0001728f;
pmic 3:4a2cd363c443 76 float usOffset = 0.0215916f;
pmic 3:4a2cd363c443 77 // Sensor 2
pmic 3:4a2cd363c443 78 float usGain = 0.0001731f;
pmic 3:4a2cd363c443 79 float usOffset = 0.0186031f;
pmic 3:4a2cd363c443 80 */
pmic 3:4a2cd363c443 81
pmic 3:4a2cd363c443 82 // user defined functions
pmic 3:4a2cd363c443 83 void updateLoop(void); // loop (via interrupt)
pmic 3:4a2cd363c443 84 void pressed(void); // user Button pressed
pmic 3:4a2cd363c443 85 void released(void); // user Button released
NickRyder 0:186bb2174995 86
pmic 3:4a2cd363c443 87 // main program and control loop
pmic 3:4a2cd363c443 88 // -----------------------------------------------------------------------------
pmic 3:4a2cd363c443 89 int main()
pmic 3:4a2cd363c443 90 {
pmic 3:4a2cd363c443 91 pc.baud(2000000); // for serial comm.
pmic 3:4a2cd363c443 92 LoopTimer.attach(&updateLoop, Ts); // attach loop to timer interrupt
pmic 3:4a2cd363c443 93 Button.fall(&pressed); // attach key pressed function
pmic 3:4a2cd363c443 94 Button.rise(&released); // attach key pressed function
pmic 3:4a2cd363c443 95 k = 0;
pmic 3:4a2cd363c443 96 pt1.reset(0.0f);
pmic 3:4a2cd363c443 97 }
pmic 3:4a2cd363c443 98
pmic 3:4a2cd363c443 99 // original
pmic 3:4a2cd363c443 100 /*
pmic 3:4a2cd363c443 101 if (d == -1.0) {
pmic 3:4a2cd363c443 102 printf("Timeout Error.\n");
pmic 3:4a2cd363c443 103 } else if (d > 5.0) {
pmic 3:4a2cd363c443 104 // Seeed's sensor has a maximum range of 4m, it returns
pmic 3:4a2cd363c443 105 // something like 7m if the ultrasound pulse isn't reflected.
pmic 3:4a2cd363c443 106 printf("No object within detection range.\n");
pmic 3:4a2cd363c443 107 } else {
pmic 3:4a2cd363c443 108 printf("Distance = %f m.\n", d);
pmic 3:4a2cd363c443 109 }
pmic 3:4a2cd363c443 110 */
pmic 3:4a2cd363c443 111
pmic 3:4a2cd363c443 112 // the updateLoop starts as soon as you pressed the blue botton
pmic 3:4a2cd363c443 113 void updateLoop(void)
pmic 3:4a2cd363c443 114 {
pmic 3:4a2cd363c443 115 // d = usGain*rf.read_m() + usOffset;
pmic 3:4a2cd363c443 116 d = rf.read_m();
pmic 3:4a2cd363c443 117 df = pt1(d);
pmic 3:4a2cd363c443 118 if(doRun) {
pmic 4:881e860d7de1 119 /*
pmic 3:4a2cd363c443 120 // use this section to do dynamical measurements
pmic 3:4a2cd363c443 121 if(doRun && k++ < 4000) {
pmic 3:4a2cd363c443 122 pc.printf("%10i %10.9e\r\n", k, d);
NickRyder 0:186bb2174995 123 }
pmic 4:881e860d7de1 124 */
pmic 4:881e860d7de1 125 ///*
pmic 3:4a2cd363c443 126 // use this section to do static measurements
pmic 3:4a2cd363c443 127 if(doRun && k++%25 == 0) {
pmic 3:4a2cd363c443 128 pc.printf("%10i %10.6e\r\n", k, df);
pmic 3:4a2cd363c443 129 }
pmic 4:881e860d7de1 130 //*/
NickRyder 0:186bb2174995 131 }
pmic 3:4a2cd363c443 132 }
pmic 3:4a2cd363c443 133
pmic 3:4a2cd363c443 134 // buttonhandling
pmic 3:4a2cd363c443 135 // -----------------------------------------------------------------------------
pmic 3:4a2cd363c443 136 // start timer as soon as button is pressed
pmic 3:4a2cd363c443 137 void pressed()
pmic 3:4a2cd363c443 138 {
pmic 3:4a2cd363c443 139 t.start();
pmic 3:4a2cd363c443 140 }
pmic 3:4a2cd363c443 141
pmic 3:4a2cd363c443 142 // evaluating statemachine
pmic 3:4a2cd363c443 143 void released()
pmic 3:4a2cd363c443 144 {
pmic 3:4a2cd363c443 145 // toggle state over boolean
pmic 3:4a2cd363c443 146 if(doRun) {
pmic 3:4a2cd363c443 147 k = 0;
pmic 3:4a2cd363c443 148 pt1.reset(0.0f);
pmic 3:4a2cd363c443 149 }
pmic 3:4a2cd363c443 150 doRun = !doRun;
pmic 3:4a2cd363c443 151 t.stop();
pmic 3:4a2cd363c443 152 t.reset();
pmic 3:4a2cd363c443 153 }
pmic 3:4a2cd363c443 154