mbed.org local branch of microbit-dal. The real version lives in git at https://github.com/lancaster-university/microbit-dal

Dependencies:   BLE_API nRF51822 mbed-dev-bin

Dependents:   microbit Microbit IoTChallenge1 microbit ... more

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Show/hide line numbers MicroBitThermometer.cpp Source File

MicroBitThermometer.cpp

00001 /*
00002 The MIT License (MIT)
00003 
00004 Copyright (c) 2016 British Broadcasting Corporation.
00005 This software is provided by Lancaster University by arrangement with the BBC.
00006 
00007 Permission is hereby granted, free of charge, to any person obtaining a
00008 copy of this software and associated documentation files (the "Software"),
00009 to deal in the Software without restriction, including without limitation
00010 the rights to use, copy, modify, merge, publish, distribute, sublicense,
00011 and/or sell copies of the Software, and to permit persons to whom the
00012 Software is furnished to do so, subject to the following conditions:
00013 
00014 The above copyright notice and this permission notice shall be included in
00015 all copies or substantial portions of the Software.
00016 
00017 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00018 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00019 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
00020 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00021 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
00022 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
00023 DEALINGS IN THE SOFTWARE.
00024 */
00025 
00026 #include "MicroBitConfig.h"
00027 #include "MicroBitThermometer.h"
00028 #include "MicroBitSystemTimer.h"
00029 #include "MicroBitFiber.h"
00030 
00031 /*
00032  * The underlying Nordic libraries that support BLE do not compile cleanly with the stringent GCC settings we employ
00033  * If we're compiling under GCC, then we suppress any warnings generated from this code (but not the rest of the DAL)
00034  * The ARM cc compiler is more tolerant. We don't test __GNUC__ here to detect GCC as ARMCC also typically sets this
00035  * as a compatability option, but does not support the options used...
00036  */
00037 #if !defined(__arm)
00038 #pragma GCC diagnostic ignored "-Wunused-function"
00039 #pragma GCC diagnostic push
00040 #pragma GCC diagnostic ignored "-Wunused-parameter"
00041 #endif
00042 
00043 #include "nrf_soc.h"
00044 #include "nrf_sdm.h"
00045 
00046 /*
00047  * Return to our predefined compiler settings.
00048  */
00049 #if !defined(__arm)
00050 #pragma GCC diagnostic pop
00051 #endif
00052 
00053 /**
00054   * Constructor.
00055   * Create new MicroBitThermometer that gives an indication of the current temperature.
00056   *
00057   * @param _storage an instance of MicroBitStorage used to persist temperature offset data
00058   *
00059   * @param id the unique EventModel id of this component. Defaults to MICROBIT_ID_THERMOMETER.
00060   *
00061   * @code
00062   * MicroBitStorage storage;
00063   * MicroBitThermometer thermometer(storage);
00064   * @endcode
00065   */
00066 MicroBitThermometer::MicroBitThermometer(MicroBitStorage& _storage, uint16_t id) :
00067     storage(&_storage)
00068 {
00069     this->id = id;
00070     this->samplePeriod = MICROBIT_THERMOMETER_PERIOD;
00071     this->sampleTime = 0;
00072     this->offset = 0;
00073 
00074     KeyValuePair *tempCalibration =  storage->get("tempCal");
00075 
00076     if(tempCalibration != NULL)
00077     {
00078         memcpy(&offset, tempCalibration->value, sizeof(int16_t));
00079         delete tempCalibration;
00080     }
00081 }
00082 
00083 /**
00084   * Constructor.
00085   * Create new MicroBitThermometer that gives an indication of the current temperature.
00086   *
00087   * @param id the unique EventModel id of this component. Defaults to MICROBIT_ID_THERMOMETER.
00088   *
00089   * @code
00090   * MicroBitThermometer thermometer;
00091   * @endcode
00092   */
00093 MicroBitThermometer::MicroBitThermometer(uint16_t id) :
00094     storage(NULL)
00095 {
00096     this->id = id;
00097     this->samplePeriod = MICROBIT_THERMOMETER_PERIOD;
00098     this->sampleTime = 0;
00099     this->offset = 0;
00100 }
00101 
00102 /**
00103   * Gets the current temperature of the microbit.
00104   *
00105   * @return the current temperature, in degrees celsius.
00106   *
00107   * @code
00108   * thermometer.getTemperature();
00109   * @endcode
00110   */
00111 int MicroBitThermometer::getTemperature()
00112 {
00113     updateSample();
00114     return temperature - offset;
00115 }
00116 
00117 
00118 /**
00119   * Updates the temperature sample of this instance of MicroBitThermometer
00120   * only if isSampleNeeded() indicates that an update is required.
00121   *
00122   * This call also will add the thermometer to fiber components to receive
00123   * periodic callbacks.
00124   *
00125   * @return MICROBIT_OK on success.
00126   */
00127 int MicroBitThermometer::updateSample()
00128 {
00129     if(!(status & MICROBIT_THERMOMETER_ADDED_TO_IDLE))
00130     {
00131         // If we're running under a fiber scheduer, register ourselves for a periodic callback to keep our data up to date.
00132         // Otherwise, we do just do this on demand, when polled through our read() interface.
00133         fiber_add_idle_component(this);
00134         status |= MICROBIT_THERMOMETER_ADDED_TO_IDLE;
00135     }
00136 
00137     // check if we need to update our sample...
00138     if(isSampleNeeded())
00139     {
00140         int32_t processorTemperature;
00141         uint8_t sd_enabled;
00142 
00143         // For now, we just rely on the nrf senesor to be the most accurate.
00144         // The compass module also has a temperature sensor, and has the lowest power consumption, so will run the cooler...
00145         // ...however it isn't trimmed for accuracy during manufacture, so requires calibration.
00146 
00147         sd_softdevice_is_enabled(&sd_enabled);
00148 
00149         if (sd_enabled)
00150         {
00151             // If Bluetooth is enabled, we need to go through the Nordic software to safely do this
00152             sd_temp_get(&processorTemperature);
00153         }
00154         else
00155         {
00156             // Othwerwise, we access the information directly...
00157             uint32_t *TEMP = (uint32_t *)0x4000C508;
00158 
00159             NRF_TEMP->TASKS_START = 1;
00160 
00161             while (NRF_TEMP->EVENTS_DATARDY == 0);
00162 
00163             NRF_TEMP->EVENTS_DATARDY = 0;
00164 
00165             processorTemperature = *TEMP;
00166 
00167             NRF_TEMP->TASKS_STOP = 1;
00168         }
00169 
00170 
00171         // Record our reading...
00172         temperature = processorTemperature / 4;
00173 
00174         // Schedule our next sample.
00175         sampleTime = system_timer_current_time() + samplePeriod;
00176 
00177         // Send an event to indicate that we'e updated our temperature.
00178         MicroBitEvent e(id, MICROBIT_THERMOMETER_EVT_UPDATE);
00179     }
00180 
00181     return MICROBIT_OK;
00182 };
00183 
00184 /**
00185   * Periodic callback from MicroBit idle thread.
00186   */
00187 void MicroBitThermometer::idleTick()
00188 {
00189     updateSample();
00190 }
00191 
00192 /**
00193   * Determines if we're due to take another temperature reading
00194   *
00195   * @return 1 if we're due to take a temperature reading, 0 otherwise.
00196   */
00197 int MicroBitThermometer::isSampleNeeded()
00198 {
00199     return  system_timer_current_time() >= sampleTime;
00200 }
00201 
00202 /**
00203   * Set the sample rate at which the temperatureis read (in ms).
00204   *
00205   * The default sample period is 1 second.
00206   *
00207   * @param period the requested time between samples, in milliseconds.
00208   *
00209   * @note the temperature is always read in the background, and is only updated
00210   * when the processor is idle, or when the temperature is explicitly read.
00211   */
00212 void MicroBitThermometer::setPeriod(int period)
00213 {
00214     updateSample();
00215     samplePeriod = period;
00216 }
00217 
00218 /**
00219   * Reads the currently configured sample rate of the thermometer.
00220   *
00221   * @return The time between samples, in milliseconds.
00222   */
00223 int MicroBitThermometer::getPeriod()
00224 {
00225     return samplePeriod;
00226 }
00227 
00228 /**
00229   * Set the value that is used to offset the raw silicon temperature.
00230   *
00231   * @param offset the offset for the silicon temperature
00232   *
00233   * @return MICROBIT_OK on success
00234   */
00235 int MicroBitThermometer::setOffset(int offset)
00236 {
00237     if(this->storage != NULL)
00238         this->storage->put(ManagedString("tempCal"), (uint8_t *)&offset, sizeof(int));
00239 
00240     this->offset = offset;
00241 
00242     return MICROBIT_OK;
00243 }
00244 
00245 /**
00246   * Retreive the value that is used to offset the raw silicon temperature.
00247   *
00248   * @return the current offset.
00249   */
00250 int MicroBitThermometer::getOffset()
00251 {
00252     return offset;
00253 }
00254 
00255 /**
00256   * This member function fetches the raw silicon temperature, and calculates
00257   * the value used to offset the raw silicon temperature based on a given temperature.
00258   *
00259   * @param calibrationTemp the temperature used to calculate the raw silicon temperature
00260   * offset.
00261   *
00262   * @return MICROBIT_OK on success
00263   */
00264 int MicroBitThermometer::setCalibration(int calibrationTemp)
00265 {
00266     updateSample();
00267     return setOffset(temperature - calibrationTemp);
00268 }