Can you replace the shield? Sorry, new to embedded systems. Are they onboard? If not, how does it find the waveforms? Can they just be on flash or do they have to be in RAM? And can I add my own waveforms? No worries. This IC fabricates the sounds directly. It's not loading waveforms, it's generating them mathematically.
No RAM or flash needed. You just ask it to give you a C note from a Violin and it does its best to generate a Violin C. You can't add your own instruments as far as I know. Will the MP3 player be able to play multiple files at the same time? Hope somebody could advice me on this! I then bought an UNO, and it worked fine. The difference? The DUE defaults pin 4 as an input with a pull up.
I thought the Due was 3. This board seems to be 5V from the diagram. You got it to work with the Due without burning anything out? How did you get it to work? I had to go and comment out some lines in the SFEMP3 library calls to cli and sei , disable and enable interrupts before it would compile for a DUE, and now I get an error message running the test sketch saying that it can't access the SD card.
Spent 10 minutes setting up the shield on a redboard. Ran through the "FilePlayer" sketch. Worked like a charm. Ran through the "MP3 Trigger" sketch. Made a few mods to the MP3 trigger sketch to fit my needs. After a couple of days of pulling my hair out trying to figure out why everything worked seamlessly when plugged into the computer USB, but would only work maybe 1 out of 10 times when plugged straight into the wall, it dawned on me.
After staring at the sketch, I thought that maybe the Mp3 file player and the MicroSD card reader did not have enough time to initialize, and therefore, caused an error. After playing around with a few delays throughout the setup procedure, I finally got it. By putting a 4 second delay at the beginning of setup, another 4 second delay after the sd card reader initialization, and a final 4 second delay after the mp3 initialization before the loop begins, it worked perfectly!
After playing with the delay timing for a while, I found that a 2 second delay would work 1 out of 5 times. A 3 second delay worked about 3 or 4 out of 5 times. While a 4 second delay did the trick.
Now, it does exactly what I needed it to do. I was unable to find much reference anywhere to anyone having an issue such as this? I was also unable to find many references of people powering this shield with a wall wort as opposed to USB from a computer? Hope this helps someone! Having purchased and built with 9 of these shields 7 from SparkFun, 2 from Mouser , I can confirm that they're very easy to use and inexpensive for what they do. That first shield has since stopped working altogether, so maybe it was defective, I dunno.
I'd also like to add that the audio is fairly noisy--sounds like digital noise bleeding into the analog output--so you will want to keep the fidelity of your playback system fairly low.
I got one shield that sounded like it had excessive data req noise in the output, which was the first time I became aware that there was any unusual noise at all.
It sounded like a 16mm film projector from the '70s. Some of the noise can be addressed by adding extra Vcc bypass caps. Bottom line: if it's gotta work, budget one or two extras to be safe. Update: I just updated both the SD library and the shield library and that appears to have addressed the initialization issues I have been occasionally seeing. Check to make sure you have the latest. This is a very nice shield for Arduino, it worked smoothly and I was able to connect play audio files with some push buttons.
Pros: Can play a specific audio track by calling its name, cheap price. Cons: Separate pin headers, have to solder them, have to install 4 libraries, limited to only 9 audio tracks to be played. Audio tracks have to be of DOS 8.
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Radio View all. Videos View all. Movies View all. Artists View all. Video Playlists View all. TV Shows View all. Episodes View all. The growth of urbanization and technological advances favor the increased noise levels on the streets, at work and at play 1. In recent years, the use of devices MP3 players has increased dramatically.
It is very common to see people listening to music on MP3 players, either in his morning walk, riding a bike, bus or working out, and often with a very high volume, ie the daily life of people has become a disturbing symphony. Often the volume of the device is further amplified when the user is in a noisy location 3 3. Characteristics of noise-canceling headphones to reduce the hearing hazard for MP3 users. Music is seen as a pleasant sound, and so it is usually associated with important events in the life of every individual, giving pleasure to those who hear, so it is seen as being unable to cause harm to humans.
However, when used intensively and for a long period of exposure, can cause auditory disorder 4 4. Catarinense de Med. The power of handheld devices can reach decibels, the same power turbine of an airplane at takeoff 5 5.
Consiglio A. Observed that, then comes a very big concern for the health of people who use MP3 Player devices for hours, increasing the risk of a person has a hearing impairment. What people do not realize is that this musical outing, when at high intensity can cause cell damage, which may be temporary or permanent. Hearing loss due to using headphone is discussed for years. Research in the U. Some manufacturers already use a mechanism that warns the user that it exceeded the exposure limit.
This technique, which relates to the volume usage time, based on the emission of sound whistles with frequencies that avoid masking the music. The user hears the whistle, which hinders the enjoyment of music and the volume decrease after the whistle ceases to exist. This attenuation was previously practiced by shorter battery life on a Discman or the short duration of the old media 2 hours for K-7 tape and 80 minutes for CD , while today there are batteries that last up to 20 hours straight 6 6.
Diniz T. Besides the durability of the batteries, another aggravating factor is the design of the headphones 7 7. Insert earphones are more dangerous because they intensify the sound. When the sound source is external, there is a loss of vibrational energy in the path between it and the ear, however, with the earpiece in the ear, all the energy goes 6 6.
The headphones are considered by doctors because they carry the most harmful sounds up to decibels directly to the eardrum, collaborating with the onset of tinnitus, even before causing any noticeable hearing loss 8 8.
Rajczuk L. A study at Harvard Medical School showed that the use of headphones type insertion increases levels of sound in 9 dB when compared to supra-aural headphones 9 9. Momensohn-Santos TM. IEAA [base de dados na internet]. The frequencies that capture the sounds kHz are more fragile, so often hearing loss first affects the perception of treble.
This characteristic is reported as induced by high sound pressure levels hearing loss, described in the literature as permanent threshold shift resulting from overexposure to noise, the sensorineural type, usually bilateral and symmetrical, irreversible 10 Riveiro VFM.
Pure tone audiometry is the universally adopted method and the one suggested by Ordinance No. Another disadvantage is its low sensitivity to detect subtle cochlear changes that occur before that hearing loss is manifested on the audiogram 18 The best investigation for the detection of an injury is the examination of otoacoustic emissions OAE , but has greater sensitivity to observe outer hair cell lesions, which are the first to be affected 19 Souza DV.
An estimated 25 million Brazilians have some hearing loss. This population are from people who were born with hearing impairment or are suffering from any disease that affects the auditory system, the case of diabetes, even those who, because they are frequently exposed to excessive noise, suffered injuries. One reason for that hearing impairment is manifest that society has become accustomed to exposure to sounds exaggerated. It is known that the auditory system can tolerate without risk of injury, exposure to 85 decibels for eight hours, and every five decibels more, the tolerance is reduced to half the time.
One symptom that something is not right with the ears, in addition to tinnitus, is the difficulty to understand what people say, or not satisfied with the volume of a song even being already at a high volume. Currently occupational noise are not the only sources of concern, leisure noise objects are increasingly constant study, for which the risk of injury to the inner ear can be minimized.
Held explanatory research in order to ascertain the effects of the MP3 Player device in the hearing of its users. To carry out this sampling, thirty otologically normal subjects were evaluated by otoscopy , with the result passes the exam Transient Otoacoustic Emissions, aged years old, female, and age and gender were not used as selection criteria. The volunteers were divided into two groups: Control Group CG composed of fifteen volunteers, which made use of fifteen-minute Mp3 player, with an average intensity of 85 dB HL.
Analysis Group GA consisting of fifteen volunteers, which made use of for fifteen minutes Mp3 player, with an average intensity of dB HL. The pass criterion used was that the subjects had a response to Transient Otoacoustic Emissions with signal to noise greater than 6. The Transient otoacoustic emissions were performed three times and recorded in a table Figure 1 and were later transcribed into another table already with the result of the average of the three frequencies collected and the results of otoacoustic emission distortion product Figure 2.
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