/**
* @file sensor.c
- * @purpose Implementation of sensor thread
+ * @brief Implementation of sensor thread
* TODO: Finalise implementation
*/
-
-
+#include "common.h"
#include "sensor.h"
-#include "log.h"
+#include "options.h"
#include <math.h>
+/** Array of sensors, initialised by Sensor_Init **/
+static Sensor g_sensors[NUMSENSORS]; //global to this file
+
+/** Human readable names for the sensors **/
+const char * g_sensor_names[NUMSENSORS] = {
+ "analog_test0", "analog_test1",
+ "digital_test0", "digital_test1"
+};
+
/**
- * Read a data value from a sensor; block until value is read
- * @param sensor_id - The ID of the sensor
- * @returns The current value of the sensor
+ * One off initialisation of *all* sensors
*/
-DataPoint GetData(int sensor_id)
+void Sensor_Init()
{
- // switch based on the sensor_id at the moment for testing;
- // might be able to just directly access ADC from sensor_id?
- //TODO: Implement for real sensors
-
- DataPoint d;
- //TODO: Deal with time stamps properly
- static int count = 0;
- d.time = count++;
- switch (sensor_id)
+ for (int i = 0; i < NUMSENSORS; ++i)
{
- case SENSOR_TEST0:
- d.value = count;
- break;
- case SENSOR_TEST1:
- d.value = (float)(rand() % 100) / 100;
- break;
- default:
- Fatal("Unknown sensor id: %d", sensor_id);
- break;
- }
- usleep(100000); // simulate delay in sensor polling
- return d;
+ g_sensors[i].id = i;
+ Data_Init(&(g_sensors[i].data_file));
+ g_sensors[i].record_data = false;
+ }
}
-
/**
- * Destroy a sensor
- * @param s - Sensor to destroy
+ * Start a Sensor recording DataPoints
+ * @param s - The Sensor to start
+ * @param experiment_name - Prepended to DataFile filename
*/
-void Destroy(Sensor * s)
+void Sensor_Start(Sensor * s, const char * experiment_name)
{
- //TODO: Surely we'll need to do something here?
- // Maybe move the binary file into long term file storage?
-}
+ // Set filename
+ char filename[BUFSIZ];
+ if (sprintf(filename, "%s_s%d", experiment_name, s->id) >= BUFSIZ)
+ {
+ Fatal("Experiment name \"%s\" too long (>%d)", experiment_name, BUFSIZ);
+ }
+ Log(LOGDEBUG, "Sensor %d with DataFile \"%s\"", s->id, filename);
+ // Open DataFile
+ Data_Open(&(s->data_file), filename);
+ s->record_data = true; // Don't forget this!
+
+ // Create the thread
+ pthread_create(&(s->thread), NULL, Sensor_Loop, (void*)(s));
+}
/**
- * Initialise a sensor
- * @param s - Sensor to initialise
+ * Stop a Sensor from recording DataPoints. Blocks until it has stopped.
+ * @param s - The Sensor to stop
*/
-void Sensor_Init(Sensor * s, int id)
+void Sensor_Stop(Sensor * s)
{
- s->write_index = 0;
- s->read_offset = 0;
- s->id = id;
-
- if (s->id >= pow(10, FILENAMESIZE))
+ // Stop
+ if (s->record_data)
{
- Fatal("Too many sensors! FILENAMESIZE is %d; increase it and recompile.", FILENAMESIZE);
+ s->record_data = false;
+ pthread_join(s->thread, NULL); // Wait for thread to exit
+ Data_Close(&(s->data_file)); // Close DataFile
+ s->newest_data.time_stamp = 0;
+ s->newest_data.value = 0;
}
- sprintf(s->filename, "%d", s->id);
- unlink(s->filename); //TODO: Move old files somewhere
+}
- Log(LOGDEBUG, "Initialised sensor %d; binary file is \"%s\"", id, s->filename);
+/**
+ * Stop all Sensors
+ */
+void Sensor_StopAll()
+{
+ for (int i = 0; i < NUMSENSORS; ++i)
+ Sensor_Stop(g_sensors+i);
}
+/**
+ * Start all Sensors
+ */
+void Sensor_StartAll(const char * experiment_name)
+{
+ for (int i = 0; i < NUMSENSORS; ++i)
+ Sensor_Start(g_sensors+i, experiment_name);
+}
/**
- * Run the main sensor polling loop
- * @param arg - Cast to Sensor* - Sensor that the thread will handle
- * @returns NULL (void* required to use the function with pthreads)
+ * Read a DataPoint from a Sensor; block until value is read
+ * @param id - The ID of the sensor
+ * @param d - DataPoint to set
+ * @returns True if the DataPoint was different from the most recently recorded.
*/
-void * Sensor_Main(void * arg)
+bool Sensor_Read(Sensor * s, DataPoint * d)
{
- Sensor * s = (Sensor*)(arg);
+
+ // Set time stamp
+ struct timeval t;
+ gettimeofday(&t, NULL);
+ d->time_stamp = TIMEVAL_DIFF(t, g_options.start_time);
- while (true) //TODO: Exit condition
+ // Read value based on Sensor Id
+ switch (s->id)
{
- // The sensor will write data to a buffer until it is full
- // Then it will open a file and dump the buffer to the end of it.
- // Rinse and repeat
-
- // The reason I've added the buffer is because locks are expensive
- // But maybe it's better to just write data straight to the file
- // I'd like to do some tests by changing SENSOR_DATABUFSIZ
+ case ANALOG_TEST0:
+ d->value = (double)(rand() % 100) / 100;
+ break;
- while (s->write_index < SENSOR_DATABUFSIZ)
+ case ANALOG_TEST1:
{
- s->buffer[s->write_index] = GetData(s->id);
- s->write_index += 1;
+ static int count = 0;
+ d->value = count++;
+ break;
}
+ case DIGITAL_TEST0:
+ d->value = t.tv_sec % 2;
+ break;
+ case DIGITAL_TEST1:
+ d->value = (t.tv_sec+1)%2;
+ break;
+ default:
+ Fatal("Unknown sensor id: %d", s->id);
+ break;
+ }
+ usleep(100000); // simulate delay in sensor polling
- //Log(LOGDEBUG, "Filled buffer");
+ // Perform sanity check based on Sensor's ID and the DataPoint
+ Sensor_CheckData(s->id, d);
- // CRITICAL SECTION (no threads should be able to read/write the file at the same time)
- pthread_mutex_lock(&(s->mutex));
+ // Update latest DataPoint if necessary
+ bool result = (d->value != s->newest_data.value);
+ if (result)
+ {
+ s->newest_data.time_stamp = d->time_stamp;
+ s->newest_data.value = d->value;
+ }
+ return result;
+}
- // Open binary file in append mode and dump buffer into it
- FILE * file = fopen(s->filename, "ab");
- if (file == NULL)
+/**
+ * Checks the sensor data for unsafe or unexpected results
+ * @param sensor_id - The ID of the sensor
+ * @param d - DataPoint to check
+ */
+void Sensor_CheckData(SensorId id, DataPoint * d)
+{
+ //TODO: Implement
+ /*
+ switch (sensor_id)
+ {
+ case ANALOG_TEST0:
+ {
+ if( *sensor value* > ANALOG_TEST0_SAFETY)
{
- Fatal("Couldn't open file \"%s\" mode ab - %s", s->filename, strerror(errno));
+ LogEx(LOGERR, GetData, Sensor analog_test0 is above the safe value);
+ //new log function that stops actuators?
}
- int amount_written = fwrite(s->buffer, sizeof(DataPoint), SENSOR_DATABUFSIZ, file);
- if (amount_written != SENSOR_DATABUFSIZ)
+ //Also include a warning level?
+ else if( *sensor value* > ANALOG_TEST0_WARN)
{
- Fatal("Wrote %d data points and expected to write %d to \"%s\" - %s", amount_written, SENSOR_DATABUFSIZ, strerror(errno));
+ LogEx(LOGWARN, GetData, Sensor analog_test0);
}
+ }
+ }
+ */
+}
+
+
+/**
+ * Record data from a single Sensor; to be run in a seperate thread
+ * @param arg - Cast to Sensor* - Sensor that the thread will handle
+ * @returns NULL (void* required to use the function with pthreads)
+ */
+void * Sensor_Loop(void * arg)
+{
+ Sensor * s = (Sensor*)(arg);
+ Log(LOGDEBUG, "Sensor %d starts", s->id);
+
+ // Until the sensor is stopped, record data points
+ while (s->record_data)
+ {
+ DataPoint d;
+ //Log(LOGDEBUG, "Sensor %d reads data [%f,%f]", s->id, d.time_stamp, d.value);
+ if (Sensor_Read(s, &d)) // If new DataPoint is read:
+ {
+ //Log(LOGDEBUG, "Sensor %d saves data [%f,%f]", s->id, d.time_stamp, d.value);
+ Data_Save(&(s->data_file), &d, 1); // Record it
+ }
+ }
+
+ // Needed to keep pthreads happy
+
+ Log(LOGDEBUG, "Sensor %d finished", s->id);
+ return NULL;
+}
- Log(LOGDEBUG, "Wrote %d data points for sensor %d", amount_written, s->id);
+/**
+ * Get a Sensor given an ID string
+ * @param id_str ID string
+ * @returns Sensor* identified by the string; NULL on error
+ */
+Sensor * Sensor_Identify(const char * id_str)
+{
+ char * end;
+ // Parse string as integer
+ int id = strtol(id_str, &end, 10);
+ if (*end != '\0')
+ {
+ return NULL;
+ }
+ // Bounds check
+ if (id < 0 || id >= NUMSENSORS)
+ return NULL;
- fclose(file);
- pthread_mutex_unlock(&(s->mutex));
- // End of critical section
+ Log(LOGDEBUG, "Sensor \"%s\" identified", g_sensor_names[id]);
+ return g_sensors+id;
+}
- s->write_index = 0; // reset position in buffer
-
+/**
+ * Helper: Begin sensor response in a given format
+ * @param context - the FCGIContext
+ * @param format - Format
+ * @param id - ID of sensor
+ */
+void Sensor_BeginResponse(FCGIContext * context, SensorId id, DataFormat format)
+{
+ // Begin response
+ switch (format)
+ {
+ case JSON:
+ FCGI_BeginJSON(context, STATUS_OK);
+ FCGI_JSONLong("id", id);
+ break;
+ default:
+ FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
+ break;
}
- return NULL;
+}
+
+/**
+ * Helper: End sensor response in a given format
+ * @param context - the FCGIContext
+ * @param id - ID of the sensor
+ * @param format - Format
+ */
+void Sensor_EndResponse(FCGIContext * context, SensorId id, DataFormat format)
+{
+ // End response
+ switch (format)
+ {
+ case JSON:
+ FCGI_EndJSON();
+ break;
+ default:
+ break;
+ }
+}
+
+/**
+ * Handle a request to the sensor module
+ * @param context - The context to work in
+ * @param params - Parameters passed
+ */
+void Sensor_Handler(FCGIContext *context, char * params)
+{
+ struct timeval now;
+ gettimeofday(&now, NULL);
+ double current_time = TIMEVAL_DIFF(now, g_options.start_time);
+
+ int id = 0;
+ double start_time = 0;
+ double end_time = current_time;
+ char * fmt_str;
+
+ // key/value pairs
+ FCGIValue values[] = {
+ {"id", &id, FCGI_REQUIRED(FCGI_LONG_T)},
+ {"format", &fmt_str, FCGI_STRING_T},
+ {"start_time", &start_time, FCGI_DOUBLE_T},
+ {"end_time", &end_time, FCGI_DOUBLE_T},
+ };
+
+ // enum to avoid the use of magic numbers
+ typedef enum {
+ ID,
+ FORMAT,
+ START_TIME,
+ END_TIME,
+ } SensorParams;
+
+ // Fill values appropriately
+ if (!FCGI_ParseRequest(context, params, values, sizeof(values)/sizeof(FCGIValue)))
+ {
+ // Error occured; FCGI_RejectJSON already called
+ return;
+ }
+
+
+ // Error checking on sensor id
+ if (id < 0 || id >= NUMSENSORS)
+ {
+ FCGI_RejectJSON(context, "Invalid sensor id");
+ return;
+ }
+ Sensor * s = g_sensors+id;
+
+ DataFormat format = Data_GetFormat(&(values[FORMAT]));
+
+ // Begin response
+ Sensor_BeginResponse(context, id, format);
+
+ // Print Data
+ Data_Handler(&(s->data_file), &(values[START_TIME]), &(values[END_TIME]), format, current_time);
+
+ // Finish response
+ Sensor_EndResponse(context, id, format);
+
}