Thomas Hamilton
Interface class for the Max Botix ultrasonic range finder model 1210. It includes input methods for PWM, Analog, and Serial. A PwmIn class was created to allow the PWM input to be read. Now includes automatic range update via interrupts.
MB1210.cpp@2:997b4057c879, 2010-08-23 (annotated)
- Committer:
- Blaze513
- Date:
- Mon Aug 23 07:11:10 2010 +0000
- Revision:
- 2:997b4057c879
- Parent:
- 1:b533b95e807a
- Child:
- 3:05183e50a923
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| Blaze513 | 2:997b4057c879 | 1 | //mbed Microcontroller Library |
| Blaze513 | 2:997b4057c879 | 2 | //Max Botix Ultrasonic Range Finder MB1210 Interface |
| Blaze513 | 2:997b4057c879 | 3 | //Copyright 2010 |
| Blaze513 | 2:997b4057c879 | 4 | //Thomas Hamilton |
| Blaze513 | 2:997b4057c879 | 5 | |
| Blaze513 | 0:3d969e0b4ca0 | 6 | #include "MB1210.h" |
| Blaze513 | 0:3d969e0b4ca0 | 7 | |
| Blaze513 | 1:b533b95e807a | 8 | MB1210::MB1210(PinName pw, PinName an, PinName tx, PinName rx) : OperatingMode(0x00), |
| Blaze513 | 1:b533b95e807a | 9 | UnitFactor(1), PwmScalingFactor(17014.5), AnalogScalingFactor(1024), Range(0) |
| Blaze513 | 0:3d969e0b4ca0 | 10 | { |
| Blaze513 | 0:3d969e0b4ca0 | 11 | if (rx != NC) |
| Blaze513 | 0:3d969e0b4ca0 | 12 | { |
| Blaze513 | 0:3d969e0b4ca0 | 13 | SerialInput = new Serial(NC, rx); |
| Blaze513 | 0:3d969e0b4ca0 | 14 | SerialInput->baud(9600); |
| Blaze513 | 0:3d969e0b4ca0 | 15 | SerialInput->format(8, Serial::None, 1); |
| Blaze513 | 0:3d969e0b4ca0 | 16 | OperatingMode = 0x02; |
| Blaze513 | 0:3d969e0b4ca0 | 17 | } |
| Blaze513 | 0:3d969e0b4ca0 | 18 | if (an != NC) |
| Blaze513 | 0:3d969e0b4ca0 | 19 | { |
| Blaze513 | 0:3d969e0b4ca0 | 20 | AnalogInput = new AnalogIn(an); |
| Blaze513 | 0:3d969e0b4ca0 | 21 | OperatingMode = 0x01; |
| Blaze513 | 0:3d969e0b4ca0 | 22 | } |
| Blaze513 | 0:3d969e0b4ca0 | 23 | if (pw != NC) |
| Blaze513 | 0:3d969e0b4ca0 | 24 | { |
| Blaze513 | 0:3d969e0b4ca0 | 25 | PwmInput = new PwmIn(pw); |
| Blaze513 | 0:3d969e0b4ca0 | 26 | OperatingMode = 0x00; |
| Blaze513 | 0:3d969e0b4ca0 | 27 | } |
| Blaze513 | 0:3d969e0b4ca0 | 28 | if (tx != NC) |
| Blaze513 | 0:3d969e0b4ca0 | 29 | { |
| Blaze513 | 0:3d969e0b4ca0 | 30 | SerialOutput = new DigitalOut(tx); |
| Blaze513 | 0:3d969e0b4ca0 | 31 | SerialOutput->write(0); |
| Blaze513 | 0:3d969e0b4ca0 | 32 | } |
| Blaze513 | 0:3d969e0b4ca0 | 33 | } |
| Blaze513 | 0:3d969e0b4ca0 | 34 | //constructor dynamically allocates memory and cpu time (interrupts) |
| Blaze513 | 0:3d969e0b4ca0 | 35 | //to input objects depending on how the device is connected |
| Blaze513 | 0:3d969e0b4ca0 | 36 | |
| Blaze513 | 0:3d969e0b4ca0 | 37 | MB1210::~MB1210() |
| Blaze513 | 0:3d969e0b4ca0 | 38 | { |
| Blaze513 | 0:3d969e0b4ca0 | 39 | delete PwmInput; |
| Blaze513 | 0:3d969e0b4ca0 | 40 | delete AnalogInput; |
| Blaze513 | 0:3d969e0b4ca0 | 41 | delete SerialOutput; |
| Blaze513 | 0:3d969e0b4ca0 | 42 | delete SerialInput; |
| Blaze513 | 0:3d969e0b4ca0 | 43 | delete this; |
| Blaze513 | 0:3d969e0b4ca0 | 44 | } |
| Blaze513 | 0:3d969e0b4ca0 | 45 | //input objects must be deallocated |
| Blaze513 | 0:3d969e0b4ca0 | 46 | |
| Blaze513 | 0:3d969e0b4ca0 | 47 | void MB1210::SoundVelocity(float MetersPerSecond) |
| Blaze513 | 0:3d969e0b4ca0 | 48 | { |
| Blaze513 | 0:3d969e0b4ca0 | 49 | PwmScalingFactor = (UnitFactor * MetersPerSecond * 50); |
| Blaze513 | 0:3d969e0b4ca0 | 50 | } |
| Blaze513 | 0:3d969e0b4ca0 | 51 | //set the velocity of sound for pwm readings |
| Blaze513 | 0:3d969e0b4ca0 | 52 | |
| Blaze513 | 0:3d969e0b4ca0 | 53 | void MB1210::Voltage(float Volts) |
| Blaze513 | 0:3d969e0b4ca0 | 54 | { |
| Blaze513 | 0:3d969e0b4ca0 | 55 | AnalogScalingFactor = (UnitFactor * 3379.2 / Volts); |
| Blaze513 | 0:3d969e0b4ca0 | 56 | } |
| Blaze513 | 0:3d969e0b4ca0 | 57 | //set the voltage correction factor for analog readings |
| Blaze513 | 0:3d969e0b4ca0 | 58 | |
| Blaze513 | 0:3d969e0b4ca0 | 59 | void MB1210::Unit(float UnitsPerMeter) |
| Blaze513 | 0:3d969e0b4ca0 | 60 | { |
| Blaze513 | 0:3d969e0b4ca0 | 61 | PwmScalingFactor *= (UnitsPerMeter / UnitFactor / 100); |
| Blaze513 | 0:3d969e0b4ca0 | 62 | AnalogScalingFactor *= (UnitsPerMeter / UnitFactor / 100); |
| Blaze513 | 0:3d969e0b4ca0 | 63 | UnitFactor = UnitsPerMeter / 100; |
| Blaze513 | 0:3d969e0b4ca0 | 64 | } |
| Blaze513 | 0:3d969e0b4ca0 | 65 | //set the unit factor to return the range in units other than cm |
| Blaze513 | 0:3d969e0b4ca0 | 66 | |
| Blaze513 | 0:3d969e0b4ca0 | 67 | void MB1210::Mode(char Selection) |
| Blaze513 | 0:3d969e0b4ca0 | 68 | { |
| Blaze513 | 0:3d969e0b4ca0 | 69 | if (SerialOutput) |
| Blaze513 | 0:3d969e0b4ca0 | 70 | { |
| Blaze513 | 0:3d969e0b4ca0 | 71 | SerialOutput->write(Selection & 0x04); |
| Blaze513 | 0:3d969e0b4ca0 | 72 | } |
| Blaze513 | 0:3d969e0b4ca0 | 73 | OperatingMode = Selection & 0x03; |
| Blaze513 | 0:3d969e0b4ca0 | 74 | } |
| Blaze513 | 0:3d969e0b4ca0 | 75 | //change the operating mode; SerialOutput controls synchronicity |
| Blaze513 | 0:3d969e0b4ca0 | 76 | |
| Blaze513 | 0:3d969e0b4ca0 | 77 | void MB1210::RequestSyncRead() |
| Blaze513 | 0:3d969e0b4ca0 | 78 | { |
| Blaze513 | 0:3d969e0b4ca0 | 79 | if (SerialOutput) |
| Blaze513 | 0:3d969e0b4ca0 | 80 | { |
| Blaze513 | 0:3d969e0b4ca0 | 81 | SerialOutput->write(1); |
| Blaze513 | 0:3d969e0b4ca0 | 82 | wait_us(20); |
| Blaze513 | 0:3d969e0b4ca0 | 83 | SerialOutput->write(0); |
| Blaze513 | 0:3d969e0b4ca0 | 84 | } |
| Blaze513 | 0:3d969e0b4ca0 | 85 | } |
| Blaze513 | 0:3d969e0b4ca0 | 86 | //hold pin high for at least 20 us to request a synchronous range reading |
| Blaze513 | 0:3d969e0b4ca0 | 87 | |
| Blaze513 | 0:3d969e0b4ca0 | 88 | float MB1210::Read() |
| Blaze513 | 0:3d969e0b4ca0 | 89 | { |
| Blaze513 | 0:3d969e0b4ca0 | 90 | switch (OperatingMode) |
| Blaze513 | 0:3d969e0b4ca0 | 91 | { |
| Blaze513 | 0:3d969e0b4ca0 | 92 | case 0: |
| Blaze513 | 0:3d969e0b4ca0 | 93 | if (PwmInput) |
| Blaze513 | 0:3d969e0b4ca0 | 94 | { |
| Blaze513 | 0:3d969e0b4ca0 | 95 | return PwmInput->pulsewidth() * PwmScalingFactor; |
| Blaze513 | 0:3d969e0b4ca0 | 96 | } |
| Blaze513 | 0:3d969e0b4ca0 | 97 | else |
| Blaze513 | 0:3d969e0b4ca0 | 98 | { |
| Blaze513 | 0:3d969e0b4ca0 | 99 | return 0; |
| Blaze513 | 0:3d969e0b4ca0 | 100 | } |
| Blaze513 | 0:3d969e0b4ca0 | 101 | case 1: |
| Blaze513 | 0:3d969e0b4ca0 | 102 | if (AnalogInput) |
| Blaze513 | 0:3d969e0b4ca0 | 103 | { |
| Blaze513 | 0:3d969e0b4ca0 | 104 | return AnalogInput->read() * AnalogScalingFactor; |
| Blaze513 | 0:3d969e0b4ca0 | 105 | } |
| Blaze513 | 0:3d969e0b4ca0 | 106 | else |
| Blaze513 | 0:3d969e0b4ca0 | 107 | { |
| Blaze513 | 0:3d969e0b4ca0 | 108 | return 0; |
| Blaze513 | 0:3d969e0b4ca0 | 109 | } |
| Blaze513 | 0:3d969e0b4ca0 | 110 | case 2: |
| Blaze513 | 0:3d969e0b4ca0 | 111 | if (SerialInput) |
| Blaze513 | 0:3d969e0b4ca0 | 112 | { |
| Blaze513 | 1:b533b95e807a | 113 | unsigned char i = 0; |
| Blaze513 | 1:b533b95e807a | 114 | while (SerialInput->readable() && !SerialInput->scanf("R%3d", &Range) && (i < 32)) |
| Blaze513 | 0:3d969e0b4ca0 | 115 | { |
| Blaze513 | 1:b533b95e807a | 116 | SerialInput->getc(); |
| Blaze513 | 1:b533b95e807a | 117 | i++; |
| Blaze513 | 0:3d969e0b4ca0 | 118 | } |
| Blaze513 | 1:b533b95e807a | 119 | return (float)Range * UnitFactor; |
| Blaze513 | 0:3d969e0b4ca0 | 120 | } |
| Blaze513 | 0:3d969e0b4ca0 | 121 | else |
| Blaze513 | 0:3d969e0b4ca0 | 122 | { |
| Blaze513 | 0:3d969e0b4ca0 | 123 | return 0; |
| Blaze513 | 0:3d969e0b4ca0 | 124 | } |
| Blaze513 | 0:3d969e0b4ca0 | 125 | default: |
| Blaze513 | 0:3d969e0b4ca0 | 126 | return 0; |
| Blaze513 | 0:3d969e0b4ca0 | 127 | } |
| Blaze513 | 0:3d969e0b4ca0 | 128 | } |
| Blaze513 | 0:3d969e0b4ca0 | 129 | //OperatingMode switches to desired output method; |
| Blaze513 | 0:3d969e0b4ca0 | 130 | //once gathered, the result is scaled according to voltage, the speed of sound, and desired unit |
| Blaze513 | 0:3d969e0b4ca0 | 131 | void MB1210::Read(char* Buffer) |
| Blaze513 | 0:3d969e0b4ca0 | 132 | { |
| Blaze513 | 0:3d969e0b4ca0 | 133 | if (SerialInput) |
| Blaze513 | 0:3d969e0b4ca0 | 134 | { |
| Blaze513 | 1:b533b95e807a | 135 | unsigned char i = 0; |
| Blaze513 | 1:b533b95e807a | 136 | while (SerialInput->readable() && !SerialInput->scanf("R%3s", Buffer) && (i < 32)) |
| Blaze513 | 0:3d969e0b4ca0 | 137 | { |
| Blaze513 | 1:b533b95e807a | 138 | SerialInput->getc(); |
| Blaze513 | 1:b533b95e807a | 139 | i++; |
| Blaze513 | 0:3d969e0b4ca0 | 140 | } |
| Blaze513 | 0:3d969e0b4ca0 | 141 | } |
| Blaze513 | 0:3d969e0b4ca0 | 142 | } |
| Blaze513 | 0:3d969e0b4ca0 | 143 | //this overload is for serial only, regardless of selected mode; |
| Blaze513 | 0:3d969e0b4ca0 | 144 | //reads 3 ASCII character result into the given buffer |
| Blaze513 | 0:3d969e0b4ca0 | 145 | |
| Blaze513 | 0:3d969e0b4ca0 | 146 | MB1210::operator float() |
| Blaze513 | 0:3d969e0b4ca0 | 147 | { |
| Blaze513 | 0:3d969e0b4ca0 | 148 | return Read(); |
| Blaze513 | 0:3d969e0b4ca0 | 149 | } |
| Blaze513 | 0:3d969e0b4ca0 | 150 | //conversion function acts as shorthand for Read() |