ardunio to 800l sound no speakers

Projects General Guidance
21

Okay can you confirm the wiring so I know I have got it straight in my head.

I need to divide the voltage form the pwm pin from 5 to 2V? to the positive mic and gnd to the negative mic.

22

Yes but don’t forget the RC filter between the divider and the mic lead.

23

hoping to have a go at this shortly been tied up with other things.

normalised the files just need to get them to the code format cant see how to do that at the minute.

wrt to the RC filter what are the values of the components I should be using as seen a few different ones knocking about and not sure which would be the best place to start.

thanks for all you help and sorry for me keep going over things I just want to make sure I get the best start and I understand properly.

24

Use a 1.5K resistor followed by a 10nF capacitor.

You see different values because you can change both values and have the sam result. Multiplying the resistor value by the capacitor value gives you a number called the time constant. As long as the time constant is the same it will work the same. A bit like ratios in a voltage divider the absolute values only affect the output impedance.

25

Thanks. that makes a little more sense

26

Hi Mike,

I can normalise, but I don't see any options to get the code as you suggested.

is there a tutorial I can watch that takes me through this process.

Thanks
(obviously I am missing something fundamental here).

27

but I don't see any options to get the code as you suggested.

Sorry you've lost me. What code are you talking about?

28

I am unable to convert the audio file into code to play back.

29

BeWayne:
I am unable to convert the audio file into code to play back.

OK so what method are you using for the playback? So far we have only been considering the output connection.

Using the popular libiary TMRpcm Home · TMRh20/TMRpcm Wiki · GitHub will tell you about your options.

However most of that involves storing the data in an SD card.

For my method you first need a copy of Audicity ( free download ) to do the actual recording. Then save it as a "WAV (Microsoft)" for the header and "Signed 16-bit PCM" for the encoding.
Then you take the software in Listing 14.1 and run it in the Processing language ( again free download ) which prints out the data as Arduino code. You then copy that output and paste it into an Arduino program, preferably in its own TAB to make it tidy.

Then take the code in listing 14.3 and run it on an Arduino. This sample code placed the samples into the Arduino program memory and then plays it back using one of two methods.:-

  1. Synchronously - that means it plays it on the trigger of an input pin and only returns once the sample has been played, or
  2. Asynchronously - that means it plays it on the trigger of an input pin and returns immediately so you can do stuff like start the sample playing again or any do any other code.

The two listings can be downloaded from the Book's website that I posted in reply #1

30

I see the step missed, separate program..... doh feel a little stupid, but no worries the best mistakes are usually the simple ones.

thanks for you patience.

31

cool got there in the end.

load the file, press play, open the wav file as promted, save the coded file.

Processing 3.3.7 used Sound Sample file as in ch14.1

Thanks for your help on to the next step.

32

Well done for seeing it through. :slight_smile: