EmbeddedArtists AB / Mbed 2 deprecated lpc812_exp_solution_analog-in

Solutions for the Analog Input experiments for LPC812 MAX

Dependencies:   lpc812_exp_lib_PCF8591 mbed

main.cpp@0:24709c18bbe0, 2013-11-22 (annotated)

Committer:
embeddedartists
Date:
Fri Nov 22 10:31:23 2013 +0000
Revision:
0:24709c18bbe0
First version

Who changed what in which revision?

UserRevisionLine numberNew contents of line
embeddedartists 0:24709c18bbe0 1 #include "mbed.h"
embeddedartists 0:24709c18bbe0 2 #include "PCF8591.h"
embeddedartists 0:24709c18bbe0 3
embeddedartists 0:24709c18bbe0 4 Serial pc(USBTX, USBRX); // tx, rx
embeddedartists 0:24709c18bbe0 5
embeddedartists 0:24709c18bbe0 6 PCF8591 adc;
embeddedartists 0:24709c18bbe0 7
embeddedartists 0:24709c18bbe0 8 float getTrimpotValue()
embeddedartists 0:24709c18bbe0 9 {
embeddedartists 0:24709c18bbe0 10 // read a value
embeddedartists 0:24709c18bbe0 11 int v = adc.read(PCF8591::A0);
embeddedartists 0:24709c18bbe0 12
embeddedartists 0:24709c18bbe0 13 // convert it from 0..255 to 0-3.3V
embeddedartists 0:24709c18bbe0 14 float b = v;
embeddedartists 0:24709c18bbe0 15 return (b / 256) * 3.3;
embeddedartists 0:24709c18bbe0 16 }
embeddedartists 0:24709c18bbe0 17
embeddedartists 0:24709c18bbe0 18 static void experiment1()
embeddedartists 0:24709c18bbe0 19 {
embeddedartists 0:24709c18bbe0 20 pc.printf("Analog input tests\n");
embeddedartists 0:24709c18bbe0 21 while(1) {
embeddedartists 0:24709c18bbe0 22 pc.printf("%f V\n", getTrimpotValue());
embeddedartists 0:24709c18bbe0 23 wait(0.25);
embeddedartists 0:24709c18bbe0 24 }
embeddedartists 0:24709c18bbe0 25 }
embeddedartists 0:24709c18bbe0 26
embeddedartists 0:24709c18bbe0 27 int getDigit()
embeddedartists 0:24709c18bbe0 28 {
embeddedartists 0:24709c18bbe0 29 // read a value
embeddedartists 0:24709c18bbe0 30 int v = adc.read(PCF8591::A0);
embeddedartists 0:24709c18bbe0 31
embeddedartists 0:24709c18bbe0 32 // convert it from 0..255 to 0-9
embeddedartists 0:24709c18bbe0 33 return (10 * v) / 256;
embeddedartists 0:24709c18bbe0 34 }
embeddedartists 0:24709c18bbe0 35
embeddedartists 0:24709c18bbe0 36 static void experiment2()
embeddedartists 0:24709c18bbe0 37 {
embeddedartists 0:24709c18bbe0 38 pc.printf("Digit input tests\n");
embeddedartists 0:24709c18bbe0 39 while(1) {
embeddedartists 0:24709c18bbe0 40 pc.printf("%d\n", getDigit());
embeddedartists 0:24709c18bbe0 41 wait(0.25);
embeddedartists 0:24709c18bbe0 42 }
embeddedartists 0:24709c18bbe0 43 }
embeddedartists 0:24709c18bbe0 44
embeddedartists 0:24709c18bbe0 45 int getLightSensorValue(bool filter)
embeddedartists 0:24709c18bbe0 46 {
embeddedartists 0:24709c18bbe0 47 static int lastValue = -1;
embeddedartists 0:24709c18bbe0 48
embeddedartists 0:24709c18bbe0 49 // read a value
embeddedartists 0:24709c18bbe0 50 int v = adc.read(PCF8591::A1);
embeddedartists 0:24709c18bbe0 51
embeddedartists 0:24709c18bbe0 52 if (lastValue == -1) {
embeddedartists 0:24709c18bbe0 53 lastValue = v;
embeddedartists 0:24709c18bbe0 54 }
embeddedartists 0:24709c18bbe0 55
embeddedartists 0:24709c18bbe0 56 // apply filter
embeddedartists 0:24709c18bbe0 57 if (filter) {
embeddedartists 0:24709c18bbe0 58 lastValue = ((7*lastValue) + v) >> 3;
embeddedartists 0:24709c18bbe0 59 } else {
embeddedartists 0:24709c18bbe0 60 lastValue = v;
embeddedartists 0:24709c18bbe0 61 }
embeddedartists 0:24709c18bbe0 62
embeddedartists 0:24709c18bbe0 63 return lastValue;
embeddedartists 0:24709c18bbe0 64 }
embeddedartists 0:24709c18bbe0 65
embeddedartists 0:24709c18bbe0 66 static void experiment3_alt1()
embeddedartists 0:24709c18bbe0 67 {
embeddedartists 0:24709c18bbe0 68 pc.printf("Light sensor tests - unfiltered\n");
embeddedartists 0:24709c18bbe0 69 while(1) {
embeddedartists 0:24709c18bbe0 70 pc.printf("%d\n", getLightSensorValue(false));
embeddedartists 0:24709c18bbe0 71 wait(0.25);
embeddedartists 0:24709c18bbe0 72 }
embeddedartists 0:24709c18bbe0 73 }
embeddedartists 0:24709c18bbe0 74
embeddedartists 0:24709c18bbe0 75 static void experiment3_alt2()
embeddedartists 0:24709c18bbe0 76 {
embeddedartists 0:24709c18bbe0 77 pc.printf("Light sensor tests - filtered\n");
embeddedartists 0:24709c18bbe0 78 while(1) {
embeddedartists 0:24709c18bbe0 79 pc.printf("%d\n", getLightSensorValue(true));
embeddedartists 0:24709c18bbe0 80 wait(0.25);
embeddedartists 0:24709c18bbe0 81 }
embeddedartists 0:24709c18bbe0 82 }
embeddedartists 0:24709c18bbe0 83
embeddedartists 0:24709c18bbe0 84 static void experiment4()
embeddedartists 0:24709c18bbe0 85 {
embeddedartists 0:24709c18bbe0 86 int lastValue = -1000;
embeddedartists 0:24709c18bbe0 87
embeddedartists 0:24709c18bbe0 88 pc.printf("Trimpot tests with threshold\n");
embeddedartists 0:24709c18bbe0 89 while(1) {
embeddedartists 0:24709c18bbe0 90 // read a value
embeddedartists 0:24709c18bbe0 91 int value = adc.read(PCF8591::A0);
embeddedartists 0:24709c18bbe0 92 if (abs(value - lastValue) >= 5) {
embeddedartists 0:24709c18bbe0 93 pc.printf("%d\n", value);
embeddedartists 0:24709c18bbe0 94 lastValue = value;
embeddedartists 0:24709c18bbe0 95 }
embeddedartists 0:24709c18bbe0 96 wait(0.1);
embeddedartists 0:24709c18bbe0 97 }
embeddedartists 0:24709c18bbe0 98 }
embeddedartists 0:24709c18bbe0 99
embeddedartists 0:24709c18bbe0 100 int main()
embeddedartists 0:24709c18bbe0 101 {
embeddedartists 0:24709c18bbe0 102 //experiment1(); // read 0-3.3V
embeddedartists 0:24709c18bbe0 103 //experiment2(); // read digits
embeddedartists 0:24709c18bbe0 104 //experiment3_alt1(); // read light sensor data
embeddedartists 0:24709c18bbe0 105 //experiment3_alt2(); // read filtered light sensor data
embeddedartists 0:24709c18bbe0 106 experiment4(); // read trimpot data, print only big changes
embeddedartists 0:24709c18bbe0 107 }