MB1210.h

00001 //mbed Microcontroller Library
00002 //Max Botix Ultrasonic Range Finder MB1210 Interface
00003 //Copyright 2010
00004 //Thomas Hamilton
00005 
00006 #ifndef MB1210Library
00007 #define MB1210Library
00008 
00009 #include "mbed.h"
00010 #include "PwmIn.h"
00011 
00012 class MB1210
00013 {
00014     private:
00015         PwmIn* PwmInput;
00016         AnalogIn* AnalogInput;
00017         DigitalOut* SerialOutput;
00018         Serial* SerialInput;
00019 
00020         char OperatingMode;
00021         float UnitFactor;
00022         float PwmScalingFactor;
00023         float AnalogScalingFactor;
00024         float Range;
00025         float* InterruptBuffer;
00026 
00027         void Interrupt();
00028 
00029     public:
00030         MB1210(PinName pw, PinName an, PinName tx, PinName rx);
00031             //pulse width modulation input, analog input, serial output, serial input;
00032             //specify NC if pin is not used;
00033             //if the pulse width pin is used, interrupts will perform a
00034             //few microseconds of calculations every time a reading is taken
00035         ~MB1210();
00036             //deallocates PwmInput, AnalogInput, SerialOutput, and SerailInput
00037         void SoundVelocity(float MetersPerSecond);
00038             //if, for some reason, you need to correct the speed of sound
00039             //for Pwm modes, enter the new value here in meters per second;
00040             //default is 340.29 m/s
00041             //Note: most accurate mode
00042         void Voltage(float Volts);
00043             //sets expected operating voltage for Analog modes;
00044             //user responsibility to ensure operating voltage between 3.3 V and 5 V;
00045             //default is 3.3 V
00046         void Unit(float UnitsPerMeter);
00047             //argument sets the putput units through multiplication;
00048             //default is cm
00049         void Mode(char Selection);
00050             //argument sets operating mode;
00051             //set flag 0x08 to 0 for polled modes, or 1 for interrupt modes;
00052             //set flag 0x04 to 0 for synchronous modes, or 1 for asynchronous modes;
00053             //set flags 0x03 to 0 for pwm, 1 for analog, or 2 for serial;
00054             //asynchronous modes generate pulse width interrupts, prepare an
00055             //analog reading, and send a 5 byte serial reading every 99 ms;
00056             //interrupt modes automatically read the range into the buffer provided
00057             //by AttachInterruptBuffer with the selected input method every 99 ms
00058             //if in an asynchronous mode, or 99 ms after RequestSyncRead is called;
00059             //the rx pin must be connected to use an interrupt mode;
00060             //the tx pin must be connected to use a synchronous mode;
00061             //default is 0
00062         void AttachInterruptBuffer(float* Buffer);
00063             //if interrupts are used, user must provide address to write result to
00064         void RequestSyncRead();
00065             //this tells the device to prepare a synchronous range reading;
00066             //must be called at least 99 ms before the reading is needed;
00067             //changes asynchronous mode to synchronous equivalent
00068         void DiscardSerialBuffer();
00069             //the serial port has a buffer and only the oldest data is read from it;
00070             //the buffer has limited space and, when full, the newest data is discarded;
00071             //this method allows the user to empty the buffer of old data so new data is used
00072         float Read();
00073             //get a reading from the device in the set mode;
00074             //RequestSyncRead() must be called at least 99 ms
00075             //before this method can be called in a synchronous mode;
00076             //may be called at any time during asynchronous mode;
00077         operator float();
00078             //shorthand for taking a range reading;
00079             //ex: "float reading = MB1210Object;"
00080 };
00081 
00082 #endif