David's dead reckoning code for the LVBots competition on March 6th. Uses the mbed LPC1768, DRV8835, QTR-3RC, and two DC motors with encoders.
Dependencies: PololuEncoder Pacer mbed GeneralDebouncer
main.cpp@19:a11ffc903774, 2014-02-25 (annotated)
- Committer:
- DavidEGrayson
- Date:
- Tue Feb 25 02:58:16 2014 +0000
- Revision:
- 19:a11ffc903774
- Parent:
- 18:b65fbb795396
- Child:
- 20:dbec34f0e76b
Got the robot to get back to its home position and stop.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
DavidEGrayson | 0:e77a0edb9878 | 1 | #include <mbed.h> |
DavidEGrayson | 8:78b1ff957cba | 2 | #include <Pacer.h> |
DavidEGrayson | 19:a11ffc903774 | 3 | #include <math.h> |
DavidEGrayson | 0:e77a0edb9878 | 4 | |
DavidEGrayson | 8:78b1ff957cba | 5 | #include "motors.h" |
DavidEGrayson | 8:78b1ff957cba | 6 | #include "encoders.h" |
DavidEGrayson | 9:9734347b5756 | 7 | #include "leds.h" |
DavidEGrayson | 8:78b1ff957cba | 8 | #include "pc_serial.h" |
DavidEGrayson | 9:9734347b5756 | 9 | #include "test.h" |
DavidEGrayson | 12:835a4d24ae3b | 10 | #include "reckoner.h" |
DavidEGrayson | 16:8eaa5bc2bdb1 | 11 | #include "buttons.h" |
DavidEGrayson | 0:e77a0edb9878 | 12 | |
DavidEGrayson | 10:e4dd36148539 | 13 | int __attribute__((noreturn)) main() |
DavidEGrayson | 2:968338353aef | 14 | { |
DavidEGrayson | 2:968338353aef | 15 | pc.baud(115200); |
DavidEGrayson | 2:968338353aef | 16 | |
DavidEGrayson | 2:968338353aef | 17 | // Enable pull-ups on encoder pins and give them a chance to settle. |
DavidEGrayson | 9:9734347b5756 | 18 | encodersInit(); |
DavidEGrayson | 9:9734347b5756 | 19 | motorsInit(); |
DavidEGrayson | 16:8eaa5bc2bdb1 | 20 | buttonsInit(); |
DavidEGrayson | 4:1b20a11765c8 | 21 | |
DavidEGrayson | 8:78b1ff957cba | 22 | // Test routines |
DavidEGrayson | 9:9734347b5756 | 23 | //testMotors(); |
DavidEGrayson | 10:e4dd36148539 | 24 | //testEncoders(); |
DavidEGrayson | 12:835a4d24ae3b | 25 | //testLineSensors(); |
DavidEGrayson | 16:8eaa5bc2bdb1 | 26 | //testReckoner(); |
DavidEGrayson | 17:2df9861f53ee | 27 | //testButtons(); |
DavidEGrayson | 17:2df9861f53ee | 28 | testDriveHome(); |
DavidEGrayson | 2:968338353aef | 29 | |
DavidEGrayson | 4:1b20a11765c8 | 30 | while(1) |
DavidEGrayson | 4:1b20a11765c8 | 31 | { |
DavidEGrayson | 9:9734347b5756 | 32 | |
DavidEGrayson | 0:e77a0edb9878 | 33 | } |
DavidEGrayson | 0:e77a0edb9878 | 34 | } |
DavidEGrayson | 12:835a4d24ae3b | 35 | |
DavidEGrayson | 12:835a4d24ae3b | 36 | void updateReckonerFromEncoders() |
DavidEGrayson | 12:835a4d24ae3b | 37 | { |
DavidEGrayson | 12:835a4d24ae3b | 38 | while(encoderBuffer.hasEvents()) |
DavidEGrayson | 12:835a4d24ae3b | 39 | { |
DavidEGrayson | 12:835a4d24ae3b | 40 | PololuEncoderEvent event = encoderBuffer.readEvent(); |
DavidEGrayson | 12:835a4d24ae3b | 41 | switch(event) |
DavidEGrayson | 12:835a4d24ae3b | 42 | { |
DavidEGrayson | 17:2df9861f53ee | 43 | case ENCODER_LEFT | POLOLU_ENCODER_EVENT_INC: |
DavidEGrayson | 17:2df9861f53ee | 44 | reckoner.handleTickLeftForward(); |
DavidEGrayson | 17:2df9861f53ee | 45 | break; |
DavidEGrayson | 17:2df9861f53ee | 46 | case ENCODER_LEFT | POLOLU_ENCODER_EVENT_DEC: |
DavidEGrayson | 17:2df9861f53ee | 47 | reckoner.handleTickLeftBackward(); |
DavidEGrayson | 17:2df9861f53ee | 48 | break; |
DavidEGrayson | 17:2df9861f53ee | 49 | case ENCODER_RIGHT | POLOLU_ENCODER_EVENT_INC: |
DavidEGrayson | 17:2df9861f53ee | 50 | reckoner.handleTickRightForward(); |
DavidEGrayson | 17:2df9861f53ee | 51 | break; |
DavidEGrayson | 17:2df9861f53ee | 52 | case ENCODER_RIGHT | POLOLU_ENCODER_EVENT_DEC: |
DavidEGrayson | 17:2df9861f53ee | 53 | reckoner.handleTickRightBackward(); |
DavidEGrayson | 17:2df9861f53ee | 54 | break; |
DavidEGrayson | 12:835a4d24ae3b | 55 | } |
DavidEGrayson | 12:835a4d24ae3b | 56 | } |
DavidEGrayson | 12:835a4d24ae3b | 57 | } |
DavidEGrayson | 17:2df9861f53ee | 58 | |
DavidEGrayson | 19:a11ffc903774 | 59 | float magnitude() |
DavidEGrayson | 19:a11ffc903774 | 60 | { |
DavidEGrayson | 19:a11ffc903774 | 61 | return sqrt((float)reckoner.x * reckoner.x + (float)reckoner.y * reckoner.y); |
DavidEGrayson | 19:a11ffc903774 | 62 | } |
DavidEGrayson | 19:a11ffc903774 | 63 | |
DavidEGrayson | 18:b65fbb795396 | 64 | // The closer this is to zero, the closer we are to pointing towards the home position. |
DavidEGrayson | 18:b65fbb795396 | 65 | // It is basically a cross product of the two vectors (x, y) and (cos, sin). |
DavidEGrayson | 19:a11ffc903774 | 66 | float determinant() |
DavidEGrayson | 18:b65fbb795396 | 67 | { |
DavidEGrayson | 18:b65fbb795396 | 68 | // TODO: get rid of the magic numbers here (i.e. 30) |
DavidEGrayson | 18:b65fbb795396 | 69 | float s = (float)reckoner.sin / (1 << 30); |
DavidEGrayson | 18:b65fbb795396 | 70 | float c = (float)reckoner.cos / (1 << 30); |
DavidEGrayson | 19:a11ffc903774 | 71 | return (reckoner.x * s - reckoner.y * c) / magnitude(); |
DavidEGrayson | 19:a11ffc903774 | 72 | } |
DavidEGrayson | 19:a11ffc903774 | 73 | |
DavidEGrayson | 19:a11ffc903774 | 74 | int16_t reduceSpeed(int16_t speed, int16_t reduction) |
DavidEGrayson | 19:a11ffc903774 | 75 | { |
DavidEGrayson | 19:a11ffc903774 | 76 | if (reduction > speed) |
DavidEGrayson | 19:a11ffc903774 | 77 | { |
DavidEGrayson | 19:a11ffc903774 | 78 | return 0; |
DavidEGrayson | 19:a11ffc903774 | 79 | } |
DavidEGrayson | 19:a11ffc903774 | 80 | else |
DavidEGrayson | 19:a11ffc903774 | 81 | { |
DavidEGrayson | 19:a11ffc903774 | 82 | return speed - reduction; |
DavidEGrayson | 19:a11ffc903774 | 83 | } |
DavidEGrayson | 18:b65fbb795396 | 84 | } |
DavidEGrayson | 18:b65fbb795396 | 85 | |
DavidEGrayson | 18:b65fbb795396 | 86 | void __attribute__((noreturn)) driveHome() |
DavidEGrayson | 18:b65fbb795396 | 87 | { |
DavidEGrayson | 18:b65fbb795396 | 88 | led1 = 1; led2 = 1; led3 = 0; led4 = 0; |
DavidEGrayson | 18:b65fbb795396 | 89 | |
DavidEGrayson | 18:b65fbb795396 | 90 | // First, point the robot at the goal. |
DavidEGrayson | 18:b65fbb795396 | 91 | bool dir = false; |
DavidEGrayson | 18:b65fbb795396 | 92 | uint16_t transitions = 0; |
DavidEGrayson | 18:b65fbb795396 | 93 | Timer timer; |
DavidEGrayson | 18:b65fbb795396 | 94 | timer.start(); |
DavidEGrayson | 19:a11ffc903774 | 95 | |
DavidEGrayson | 19:a11ffc903774 | 96 | const int16_t maxSpeed = 300; |
DavidEGrayson | 19:a11ffc903774 | 97 | |
DavidEGrayson | 19:a11ffc903774 | 98 | while(1) |
DavidEGrayson | 18:b65fbb795396 | 99 | { |
DavidEGrayson | 18:b65fbb795396 | 100 | updateReckonerFromEncoders(); |
DavidEGrayson | 19:a11ffc903774 | 101 | |
DavidEGrayson | 19:a11ffc903774 | 102 | float magn = magnitude(); |
DavidEGrayson | 19:a11ffc903774 | 103 | |
DavidEGrayson | 19:a11ffc903774 | 104 | if (magn < (1<<17)) |
DavidEGrayson | 18:b65fbb795396 | 105 | { |
DavidEGrayson | 19:a11ffc903774 | 106 | // We are within 8 encoder ticks, so go to the next step. |
DavidEGrayson | 19:a11ffc903774 | 107 | break; |
DavidEGrayson | 19:a11ffc903774 | 108 | } |
DavidEGrayson | 19:a11ffc903774 | 109 | |
DavidEGrayson | 19:a11ffc903774 | 110 | float det = determinant(); |
DavidEGrayson | 19:a11ffc903774 | 111 | |
DavidEGrayson | 19:a11ffc903774 | 112 | { |
DavidEGrayson | 19:a11ffc903774 | 113 | bool nextDir = det > 0; |
DavidEGrayson | 18:b65fbb795396 | 114 | if (nextDir != dir) { transitions++; } |
DavidEGrayson | 18:b65fbb795396 | 115 | dir = nextDir; |
DavidEGrayson | 18:b65fbb795396 | 116 | } |
DavidEGrayson | 18:b65fbb795396 | 117 | |
DavidEGrayson | 19:a11ffc903774 | 118 | int16_t speedLeft = maxSpeed; |
DavidEGrayson | 19:a11ffc903774 | 119 | int16_t speedRight = maxSpeed; |
DavidEGrayson | 19:a11ffc903774 | 120 | if (magn < (1<<20)) // Within 64 encoder ticks of the origin, so slow down. |
DavidEGrayson | 18:b65fbb795396 | 121 | { |
DavidEGrayson | 19:a11ffc903774 | 122 | int16_t reduction = (1 - magn/(1<<20)) * maxSpeed; |
DavidEGrayson | 19:a11ffc903774 | 123 | speedLeft = reduceSpeed(speedLeft, reduction); |
DavidEGrayson | 19:a11ffc903774 | 124 | speedRight = reduceSpeed(speedRight, reduction); |
DavidEGrayson | 19:a11ffc903774 | 125 | } |
DavidEGrayson | 19:a11ffc903774 | 126 | |
DavidEGrayson | 19:a11ffc903774 | 127 | if (det > 0) |
DavidEGrayson | 19:a11ffc903774 | 128 | { |
DavidEGrayson | 19:a11ffc903774 | 129 | speedLeft = reduceSpeed(speedLeft, det * 1000); |
DavidEGrayson | 18:b65fbb795396 | 130 | } |
DavidEGrayson | 18:b65fbb795396 | 131 | else |
DavidEGrayson | 18:b65fbb795396 | 132 | { |
DavidEGrayson | 19:a11ffc903774 | 133 | speedRight = reduceSpeed(speedRight, -det * 1000); |
DavidEGrayson | 18:b65fbb795396 | 134 | } |
DavidEGrayson | 19:a11ffc903774 | 135 | motorsSpeedSet(speedLeft, speedRight); |
DavidEGrayson | 18:b65fbb795396 | 136 | } |
DavidEGrayson | 18:b65fbb795396 | 137 | |
DavidEGrayson | 19:a11ffc903774 | 138 | //while(1) |
DavidEGrayson | 18:b65fbb795396 | 139 | { |
DavidEGrayson | 18:b65fbb795396 | 140 | |
DavidEGrayson | 18:b65fbb795396 | 141 | } |
DavidEGrayson | 19:a11ffc903774 | 142 | |
DavidEGrayson | 19:a11ffc903774 | 143 | motorsSpeedSet(0, 0); |
DavidEGrayson | 19:a11ffc903774 | 144 | Pacer reportPacer(200000); |
DavidEGrayson | 19:a11ffc903774 | 145 | while(1) |
DavidEGrayson | 19:a11ffc903774 | 146 | { |
DavidEGrayson | 19:a11ffc903774 | 147 | if(reportPacer.pace()) |
DavidEGrayson | 19:a11ffc903774 | 148 | { |
DavidEGrayson | 19:a11ffc903774 | 149 | led4 = 1; |
DavidEGrayson | 19:a11ffc903774 | 150 | pc.printf("%11d %11d %11d %11d | %11f\r\n", |
DavidEGrayson | 19:a11ffc903774 | 151 | reckoner.cos, reckoner.sin, reckoner.x, reckoner.y, |
DavidEGrayson | 19:a11ffc903774 | 152 | determinant()); |
DavidEGrayson | 19:a11ffc903774 | 153 | led4 = 0; |
DavidEGrayson | 19:a11ffc903774 | 154 | } |
DavidEGrayson | 19:a11ffc903774 | 155 | } |
DavidEGrayson | 18:b65fbb795396 | 156 | } |