Hi everyone,
I'm starting my first arduino project in which I want to capture an analog signal and send it directly to the phone to process. Which Arduino would be best to use? (I'd prefer efficiency versus ease of use)
Please and thank you!
Does your "the phone" have a TTL (5V) serial port?
Efficiency in what sense? Power consumption? Size? Weight? Cost? Pin count?
Thanks for the quick response John!
I'm hoping to use the micro-USB/ lightening port on phones. So I'm not entirely sure if the phone will have a ttl(5V) serial port.
For efficiency, I'd like to keep cost low and something that doesn't add a lot of noise.
Cynz300:
I want to capture an analog signal and send it
Does that mean you want to use the ADC to sample the analog signal and send the stream of values captured by analogRead()?
How many samples per second will you need?
What is producing the analog signal?
...R
Yup, I want to sample the analog signal and send the values to the phone to analyze. The Arduino has an internal ADC correct?
I'm thinking around 44.1 kHz sampling rate and it will be a MEMS microphone.
You can sample at 44.1KHz, but you may need an external ADC.
Take a look at how an external SPI ADC was used to sample at 44.1KHz, 16 bit and stored to SD card here:
http://forum.arduino.cc/index.php?topic=180769.0
That's very informative. Thanks CrossRoads!
I'm hoping to leverage the phone's adc rather than provide one. I'm not sure if that will mess with the audio quality significantly but if there's a way to do that, I'd prefer to go that route (less parts).
Or would it make more sense to use a digital mems microphone for this task?
Cynz300:
I'm thinking around 44.1 kHz sampling rate and it will be a MEMS microphone.
The Atmega328 ADC can only do about 15ksps at full 10 bit resolution.
Even if it could work faster I suspect you will have trouble sending 44k integers per second. At the very least that is 88000 bytes and would require a continuous flow at 880,000 baud.
This sounds like a job for a RaspberryPi which would also be able to process the data before sending it anywhere.
...R
Ah good to know. Didn't realize that was the limitation.
I'd like to avoid Raspberry Pi's if at all possible. I want to leverage to phone's computing powers to do any processing.
Would I be able to connect an adc and then directly output it to the phone via USB? Or Would having a digital mems microphone and then connecting it through the arduino work as well?
Doesn't the phone have a microphone, an ADC, and processing power? Why use an Arduino at all?
I want to have improved audio, the frequency response range of the entire human hearing spectrum where standard phone microphones (at least in my case) aren't as robust.
Plus I figured it'll be a good start to working on a more serious electronics project.
Hi,
What is your electronics, programming, arduino, hardware experience?
Tom.... 
Hi Tom,
For the most part it's basic knowledge in all those fields, however, im a very quick learn.
Taken classes in programming, electronics and hardware.
Cynz300:
Would I be able to connect an adc and then directly output it to the phone via USB? Or Would having a digital mems microphone and then connecting it through the arduino work as well?
Why not just use a PC?
...R
I would like something that is light, mobile and works as an attachment to the phone. So PC doesn't work for me.
Cynz300:
I would like something that is light, mobile and works as an attachment to the phone. So PC doesn't work for me.
Is there anything available that could supply your wish?
...R
That's where I was hoping Arduino would come in.
Unless if I have a digital mems microphone, I can make a direct to USB connection? Or if I use an arduino as the appropriate bridge between phone and the mems microphone.
So I'm trying to figure out - if i can get a digital signal from a mems microphone - is there a way to send it directly to the phone or should I use the arduino as the communicator between the phone and digital microphone?
Thanks!