Output
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Overview
The script called "OutputFunc_V3.m" controls the output of the system, which consists of making sounds and turning on lights. It has gone through several changes, with different versions having different pros and cons. This script is version 3, hence the suffix "_V3", and is the first and only script with an acceptable runtime, but previous versions would have been preferred if certain tasks didn't take so much time to complete. Nevertheless, version 3 does a very good job. We've looked at different possibilities for producing sounds. Ideally, we would have connected a speaker to the Arduino, because then it would potentially be able to do all the work, without the aid of a laptop. However, that would require programming the unit in C++, in which most of us are inexperienced, and the Arduino has very limited memory space, so therefor it had been decided to use Matlab and the laptop's speaker instead. The Arduino is used to produce light, though, with added on LEDs. The sound files used for the smart alarm and the standard alarm are "Birds-singing-in-the-morning.mp3" and "Loud-alarm-clock-sound.wav" respectively, both of which have been downloaded from http://www.orangefreesounds.com/. The sound of the smart alarm can be customized by copying a sound file of your own choice to the folder containing the script and changing the filename of the smart alarm, "Alarm1", in "runscript.m". The script is capable of running with sound files of all sizes, but users are advised to use files that aren't too long, because it greatly influences the runtime of the script. The audio of "Birds-singing-in-the-morning.mp3" is about 15 minutes long, so the script is guaranteed to work with sound files of 15 minutes long or less. The standard alarm could be customized in the same manner. However, the script doesn't take into account how long the audio is and just repeats it a number of times. The script could have been altered so that it could handle sound files of different sizes, but that would increase the complexity of the code a lot, which we didn't consider to be worth the trouble. After all, it doesn't seem likely to us that the user would wish to customize the standard alarm. The audio of "Loud-alarm-clock-sound.wav" is 11 seconds long, so if you really want to, you could use another audio file of about the same size instead. Longer sound files should work as well, but we haven't tested the limits, so we can't give any guarantees.
The output script is initiated when "Complete_script.m" finds a suitable moment to wake up its user. The script is a function with 6 parameters: a connection with the Arduino, the name of the pin that controls the LEDs, the file names of the smart and standard alarm, the moment the user must be awake (the moment the standard alarm is used as a last resort to wake up the user) and finally a vector containing the number of seconds in a second, a minute, an hour and so on, which is used to translate the time and date into seconds. First of all, the script stops the measuring of sound, because the Arduino can't send and receive data at the same time. Then both sound files are translated into sound samples "y1" and "y2", which are lists of numbers between -1 and 1, and sample frequencies "Fs1" and "Fs2" which indicate how many samples need to be played per second to create the proper sound. Afterwards, the maximal sound and light intensities, "Smax" and "Lmax", are calculated using a file called "Feedback.mat". If this file doesn't exist yet, it's created and the maximal intensities are set to their defaults, which is 3 in both cases. For the light this means a maximal Arduino pin voltage of 3 V. If the maximal intensities are calculated with the feedback file, it is checked whether these values are within their boundaries, which is between 1 and 5 in both cases. If not, the value is set to 1 or 5 and the user is notified that a boundary has been reached. The minimal value is 1 so that the sound/light is still audible/visible. The maximal value of the light intensity is 5 because the Arduino has a maximal voltage of 5 V. There is no particular reason why the maximal sound volume is 5, but it seemed appropriate. The sound samples are multiplied with "Smax" to adjust their amplitude and with that the volume of the sound output. The first set of samples of the smart alarm, however, are scaled in such a way that during the first 5 minutes that the alarm is being played, the volume gradually increases from complete silence to maximal volume in order to wake up the user as lightly as possible.
Light Brightness
Play Sound
The best way to produce sound with an Arduino unit is probably by using the Sparkfun MP3 Player Shield, which is an extra circuit board for the Arduino which can play MP3 files from a microSD card (seen in the picture to the right). The costs, however, are $25, which is too much, so we chose a cheaper option. More info about this product can be found at https://www.sparkfun.com/products/12660.
Since we didn't think it is needed to buy a MP3 player shield we just used the laptop to play sounds. Matlab is doing all the calculations anyway so using the laptop to play sound is more convenient.
Two sound files have been downloaded from the internet to serve as an alarm: the file "Birds-singing-in-the-morning.mp3" is a relaxing audio with, as the name suggests, singing birds and a bit of wind. This file will serve as the Smart Alarm that softly wakes the user up. The file "Loud-alarm-clock-sound.wav" is a standard alarm sound, which will naturally serve as the standard alarm that urges the user to wake up.
When running the script, the user is first asked whether he wants to use the Smart Alarm at all. If he does, the user is then asked to give the time interval (in seconds) in which he wants to wake up. If he doesn't, the script only asks for the time the user wants to wake up. When using the Smart Alarm, the sound must gradually increase over the course of the 'wake up interval'. This is done by creating an array called f filled with linearly increasing numbers between 0 and fmax. The length of f is equal to the number of samples of the Smart Alarm sound file necessary to fill the wake up time interval. This array is then multiplied with y1, the matrix with the sound samples of the Smart Alarm. Thus during the wake up time interval, the sound increases from a maximal amplitude of 0 to a maximal amplitude of fmax. The sound is produced by using the function sound(). Using the function pause(), the script waits until the end of the wake up interval and then stops the sound, after which it starts to play the standard alarm. By using the function pause (without parameters), the script waits until the user presses a button to continue. Afterwards, the user is given the option to stop the script or continue. If he chooses to continue, he can then give feedback on the Smart Alarm (if this was enabled). The feedback consists of choosing between "Too soft", "Soft", "OK", "Loud" and "Too loud", for which the script assigns the values 2, 1, 0, -1 and -2 respectively. This number is added to the value of fmax and stored within the array Fb. The new value for fmax is determined by taking the mean of this array. To make sure that only the most recent feedback is taken into account, and limit the memory required, the maximal length of this array is set to a value called Fbmax, which is for now set to 5. When surpassing this limit, the script deletes the first element of the array Fb. The script also makes sure that the value of fmax stays between fmin and 5, and it gives a notification when it does so. From there on, the script keeps repeating itself until the user decides to stop it.
The actual script is slightly different than described above, but the description clearly shows the thought process behind this.
Description of the sound and light output
The sound and light are both two different output value’s that act separately. The sound is divided into two different audio files. On file is the sound of birds singing in the morning and the other one is the sound of an alarm clock. When the sound starts, it begins very softly with the sound of the birds singing in the morning. In the beginning, it’s barely hearable but over time, the volume becomes higher. This is because the sound is not supposed to wake you instantly, but gradually. The idea is that you are able to get used to the presence of sound before it wakes you up. When after a certain amount of time, you still didn’t wake up from the sound and therefore did not turn the alarm off, the second sound will start. This is the sound of an alarm clock as we all know it. It’s played at full volume to guarantee that you will wake up. This is not the nicest way to wake up because it will be very ‘sudden’, but it’s better than waking up too late.
The light output works in a similar way. Human beings have a natural clock build in our systems that reacts on the amount of light there is from the sun. In the early times, people did not have an alarm clock and had to wake up naturally. This was achieved by the light emitted by the sun. So that’s why we use a light pattern that’s similar to the sun’s sunrise. It’s not an exact match but it comes pretty close within the boundaries of the technology we use. The light starts at the same time as the sound does. Also, the light starts very minimally. When the sound output becomes the sound of an alarm clock, the light is also at its maximum.
After you have woken up there is the ability to give feedback to the system. With this feedback, you are able to calibrate how you want to have your light and sound input. For instance, the sound can be too loud too fast if this is the case you are able to adjust that so that next night the sound will take longer to gain in volume. If done right, it would be possible to wake up on exactly the right time in a nice way. The feedback system works as follows: You will have the opportunity to rate the output from 1-5. With 1 being too low and 5 being too loud/bright. The system then changes this for the next night. When entered 1 it will make sure that the light or sound will take higher values after a smaller amount of time, and the other way around if a 5 is given as feedback. When the feedback is 3, the output will act in the same way the next night.