Sampling.h

00001 #ifndef __Sampling__
00002 #define __Sampling__
00003 /*
00004 * This module relates to the handling and sampling of enviromental data.
00005 * Sampled data is held in 4 arrays. One for each different reading. Each
00006 * of these is protected by a mutex lock, which is taken when data is being
00007 * written to the registers.
00008 * There are common indexes for the positions in the array. Stored is the position
00009 * position of the oldest sample, the most recent sample, and where the next
00010 * sample is to be written to. These operate in such a way that the array will fill
00011 * and when fill will start to overwrite the oldest sample.
00012 * Producer functions write samples to nextIndex position, allowing the most
00013 * recent complete sample to continue to be read by consumers.
00014 * 
00015 * A ticker runs at the sample rate interval. This signals two sampling threads.
00016 * Two threads were used to prevent against delay from I2C interface.
00017 * These threads take the samples then write them to the nextIndex, then signal done.
00018 * On seeing that both threads are complete, the main thread then increments the
00019 * indexes and passes the latest variables to the LCD.
00020 */
00021 #include "mbed.h"
00022 #include "BMP280.h"
00023 #include "rtos.h"
00024 
00025 #define BUFFERSIZE 120
00026 extern unsigned short SAMPLERATE;
00027 
00028 //Thread Sync Tools
00029 extern Mutex tempReadingsLock;
00030 extern Mutex presReadingsLock;
00031 extern Mutex LDRReadingsLock;
00032 extern Mutex timeReadingsLock;
00033 
00034 //Buffers
00035 extern float tempReadings[BUFFERSIZE];
00036 extern float presReadings[BUFFERSIZE];
00037 extern float LDRReadings[BUFFERSIZE];
00038 extern time_t timeReadings[BUFFERSIZE];
00039 
00040 extern volatile unsigned short currentIndex;
00041 //Position in the buffer of the newest sample
00042 extern volatile unsigned short nextIndex;
00043 //Position in the buffer where the next sample needs to be writen to
00044 extern volatile unsigned short oldestIndex;
00045 //Position in the buffer of the oldest sample
00046 
00047 extern bool firstSample;
00048 //Used to indicate this is the first sample to be taken. used in IncrementIndex func
00049 
00050 extern Thread t1; //Sample Enviromental Sensor
00051 extern Thread t2; //Sample LDR Sensor
00052 
00053 extern Ticker sampleRate;
00054 extern Timeout SampleLEDTimeout;
00055 //Hardware
00056 extern BMP280 sensor;
00057 extern AnalogIn LDRSensor; //Input pin for LDR
00058 extern DigitalOut SamplingLED; //Onboard LED showing when a sample happens
00059 
00060 extern bool NewEnvSample;  //Is there new data from the envirom sensor to output?
00061 extern bool NewLDRSample;  //Is there new data from the LDR to output?
00062 
00063 void SampleTimerISR(void);
00064 //Called by ticker. Calls the sample funcs of each device by flagging the threads
00065 
00066 void ConfigThreadsAndIR(void);
00067 //Setup Interrupts and Threads
00068 
00069 void ThreadSampleEnvSensor(void);
00070 //when flagged by interrupt will capture a sample then calls the addtobufferfuncs
00071 
00072 void AddTempSample(float temp);
00073 //Producer function
00074 
00075 void AddPresSample(float pres);
00076 //Producer Function
00077 
00078 void ThreadSampleLDR(void);
00079 //When flagged by interrupt will read time and LDR value.
00080 
00081 void AddLDRSample(float LDR);
00082 //Producer Function
00083 
00084 void AddTimeSample(time_t sampledTime);
00085 //Producer Function
00086 
00087 void IncrementIndex(void);
00088 //Called after samples are added. Increments the index and moves the oldest
00089 //along if necessary
00090 
00091 void FlipSamplingLED(void);
00092 //Called by timeout, turns of LED
00093 
00094 unsigned short IndexIncrement(unsigned short thisIndex);
00095 //Incrementing the index with respect for the buffersize. Used to prevent overflow.
00096 
00097 unsigned short IndexDecrement(unsigned short thisIndex);
00098 //Decrementing the index with respect for the buffersize. Used to prevent overflow.
00099 
00100 void Sampling(bool inputState);
00101 //Start or stop sampling. true = start, false = stop. 
00102 
00103 void TakeKeys(bool inputState);
00104 //Lock or unlock sampling variables. true = take keys. false = return keys
00105 
00106 #endif