Coreonetech / Mbed 2 deprecated CORE-1000_rotation

Encoder test(rotation sensor) for CORE-1000

Dependencies:   mbed

main.cpp@1:38643472f93f, 2017-02-03 (annotated)

Committer:
odb
Date:
Fri Feb 03 08:02:34 2017 +0000
Revision:
1:38643472f93f
Parent:
0:75e3cf27c60b 
CORE-1000 First

Who changed what in which revision?

UserRevisionLine numberNew contents of line
zoot661 0:75e3cf27c60b 1 #include "mbed.h"
zoot661 0:75e3cf27c60b 2
odb 1:38643472f93f 3 DigitalIn phaseA( PA_0 ); // phase a of the quadrature encoder
odb 1:38643472f93f 4 DigitalIn phaseB( PA_1 ); // phase b of the quadrature encoder
odb 1:38643472f93f 5 DigitalIn click( PA_4 );
zoot661 0:75e3cf27c60b 6
zoot661 0:75e3cf27c60b 7 int encoderClickCount = 0; // hold the signed value corresponding to the number of clicks left or right since last sample
zoot661 0:75e3cf27c60b 8 int previousEncoderState = 0; // keep a record of the last actioned sample state of the Qb+Qa outputs for comparison on each interrupt
zoot661 0:75e3cf27c60b 9
zoot661 0:75e3cf27c60b 10 void quadratureDecoder( void )
zoot661 0:75e3cf27c60b 11 {
zoot661 0:75e3cf27c60b 12 int currentEncoderState = (phaseB.read() << 1) + phaseA.read(); // create a two bit value out of phaseB and phaseA
zoot661 0:75e3cf27c60b 13
zoot661 0:75e3cf27c60b 14 if( currentEncoderState == previousEncoderState )
zoot661 0:75e3cf27c60b 15 {
zoot661 0:75e3cf27c60b 16 return;
zoot661 0:75e3cf27c60b 17 }
zoot661 0:75e3cf27c60b 18
zoot661 0:75e3cf27c60b 19 switch( previousEncoderState )
zoot661 0:75e3cf27c60b 20 {
zoot661 0:75e3cf27c60b 21 case 0:
zoot661 0:75e3cf27c60b 22 if( currentEncoderState == 1 )
zoot661 0:75e3cf27c60b 23 {
zoot661 0:75e3cf27c60b 24 encoderClickCount--;
zoot661 0:75e3cf27c60b 25 }
zoot661 0:75e3cf27c60b 26 else if( currentEncoderState == 2 )
zoot661 0:75e3cf27c60b 27 {
zoot661 0:75e3cf27c60b 28 encoderClickCount++;
zoot661 0:75e3cf27c60b 29 }
zoot661 0:75e3cf27c60b 30 break;
zoot661 0:75e3cf27c60b 31
zoot661 0:75e3cf27c60b 32 case 1:
zoot661 0:75e3cf27c60b 33 if( currentEncoderState == 3 )
zoot661 0:75e3cf27c60b 34 {
zoot661 0:75e3cf27c60b 35 encoderClickCount--;
zoot661 0:75e3cf27c60b 36 }
zoot661 0:75e3cf27c60b 37 else if( currentEncoderState == 0 )
zoot661 0:75e3cf27c60b 38 {
zoot661 0:75e3cf27c60b 39 encoderClickCount++;
zoot661 0:75e3cf27c60b 40 }
zoot661 0:75e3cf27c60b 41 break;
zoot661 0:75e3cf27c60b 42
zoot661 0:75e3cf27c60b 43 case 2:
zoot661 0:75e3cf27c60b 44 if( currentEncoderState == 0 )
zoot661 0:75e3cf27c60b 45 {
zoot661 0:75e3cf27c60b 46 encoderClickCount--;
zoot661 0:75e3cf27c60b 47 }
zoot661 0:75e3cf27c60b 48 else if( currentEncoderState == 3 )
zoot661 0:75e3cf27c60b 49 {
zoot661 0:75e3cf27c60b 50 encoderClickCount++;
zoot661 0:75e3cf27c60b 51 }
zoot661 0:75e3cf27c60b 52 break;
zoot661 0:75e3cf27c60b 53
zoot661 0:75e3cf27c60b 54 case 3:
zoot661 0:75e3cf27c60b 55 if( currentEncoderState == 2 )
zoot661 0:75e3cf27c60b 56 {
zoot661 0:75e3cf27c60b 57 encoderClickCount--;
zoot661 0:75e3cf27c60b 58 }
zoot661 0:75e3cf27c60b 59 else if( currentEncoderState == 1 )
zoot661 0:75e3cf27c60b 60 {
zoot661 0:75e3cf27c60b 61 encoderClickCount++;
zoot661 0:75e3cf27c60b 62 }
zoot661 0:75e3cf27c60b 63 break;
zoot661 0:75e3cf27c60b 64
zoot661 0:75e3cf27c60b 65 default:
zoot661 0:75e3cf27c60b 66 break;
zoot661 0:75e3cf27c60b 67 }
zoot661 0:75e3cf27c60b 68 previousEncoderState = currentEncoderState;
zoot661 0:75e3cf27c60b 69 }
zoot661 0:75e3cf27c60b 70
zoot661 0:75e3cf27c60b 71 // read the rotation accumulator, and once read, reset it to zero
zoot661 0:75e3cf27c60b 72 int getClicks( void )
zoot661 0:75e3cf27c60b 73 {
zoot661 0:75e3cf27c60b 74 int res = encoderClickCount; // this allows the knob to be rotated "while im not looking at it' and still return the
zoot661 0:75e3cf27c60b 75
zoot661 0:75e3cf27c60b 76 encoderClickCount = 0; // actual number of clicks that have been rotated since last time I was checking it.
zoot661 0:75e3cf27c60b 77
zoot661 0:75e3cf27c60b 78 return res;
zoot661 0:75e3cf27c60b 79 }
zoot661 0:75e3cf27c60b 80
zoot661 0:75e3cf27c60b 81 int main()
zoot661 0:75e3cf27c60b 82 {
zoot661 0:75e3cf27c60b 83 Serial pc( USBTX, USBRX );
zoot661 0:75e3cf27c60b 84 Ticker sampleTicker; // create a timer to sample the encoder
zoot661 0:75e3cf27c60b 85 int currentClicks;
zoot661 0:75e3cf27c60b 86
zoot661 0:75e3cf27c60b 87 phaseA.mode( PullUp ); // phaseA is set with a built in pull-up resistor
zoot661 0:75e3cf27c60b 88 phaseB.mode( PullUp ); // phaseB is set with a built in pull-up resistor
zoot661 0:75e3cf27c60b 89 sampleTicker.attach_us( &quadratureDecoder, 1000 ); // make the quadrature decoder function check the knob once every 1000us = 1ms
zoot661 0:75e3cf27c60b 90
zoot661 0:75e3cf27c60b 91 pc.printf( "Encoder test started\r\n" );
zoot661 0:75e3cf27c60b 92 while( 1 )
zoot661 0:75e3cf27c60b 93 {
zoot661 0:75e3cf27c60b 94 currentClicks = getClicks();
zoot661 0:75e3cf27c60b 95 if( currentClicks != 0 )
zoot661 0:75e3cf27c60b 96 {
zoot661 0:75e3cf27c60b 97 pc.printf( "click count = %d,%d\r\n", currentClicks, previousEncoderState );
zoot661 0:75e3cf27c60b 98 }
odb 1:38643472f93f 99 if(!click)
odb 1:38643472f93f 100 { printf (" clicked \r\n");
odb 1:38643472f93f 101 }
zoot661 0:75e3cf27c60b 102 wait_ms( 200 );
zoot661 0:75e3cf27c60b 103 }
zoot661 0:75e3cf27c60b 104 }