Rephone Audio -> sound very low

Dear Admins/ Fellow Users,

I got the rephone kit create which i backed on kickstarter, and connected all the modules successfully today and tested the kit today everything is working fine but the audio is a bit very low? is there an alternative for this? or is anyone experiencing the same?

also can we buy extra craft papers for rephone kit create?


I’ll test mine soon.

If it’s really that silent, it’s possible to make one with a small amplifier, but it would seriously impact the battery life.

Hi Reddappa,

Personally, i have test my rephone with a simple call and i discover a very low sound for human voice too.
Curiously, when i try the music.mp3 (R2D2 sound) you can find in the rephone kit create directory, the sound is very good enough.

Is this normal that a human voice is a bit difficult to heard but a 8bit sound is clearly heardable ?


Tested mine, well at max volume it’s still bad for calling (and that seroius echo, no wonder all of the guys try to move the microphone).
If the R2D2 sound is played with high volume, the filters probably cut the human frequencies, or it has generally low gain. If anyone could measure the output characteristics, that would be good. Maybe the volume can be turned up by software.

If your sound is very low, try flipping the audio board around and plug it in the other way. This happened to me lol.

I’m amazed it still works when you hook it up backward.

My speaker and microphone seem to work pretty good, but do I need to upload some music or sounds for the ringer? When I call my RePhone and it receives the call it doesn’t make a sound.
How exactly do I upload music or sounds?

How exactly do I upload music or sounds?
Like the initial folder. Turn off, plug to PC, upload Mp3 (to the root folder is OK).
For setting the ringtones, select the call/SMS event in the “if” menu.

I have also problem with audio loudness… I expected to connect speaker (active) to speakers, but still it is too silent… :frowning:


is tehre any description, how audio output on MT2502 works? Meaning physically - voltages, grounded speaker output if used headphones, etc?

Is there a way how to change audio volume in SDK?

Thank you

awsome support here!
many people with a problem that makes the device useless, and nobody cares… :unamused:
is there any solution for the silent speaker out there?

i am faced the same issue. in my opinion, the call is on “normal” mode like on a phone, and it would be necessary to switch to “speaker mode”.
in the Assist SDK 2.0, there are such options, but i was not able to figure it out for the Rephone Arduino SDK.
would be great, if anyone has an idea!?

You should try a high quality audio file to check the volume of your phone. You can use the default ringtone


I am an audio lover, I use audio to make ringtones when an incoming call comes in. Free call notification sounds are available at the blog: I used for a long time and felt great!

You can create your own favorite sound and then install it on your device.