pcDuino3’s audio jack has line-in. In this post, we show two pcDuinos communicating to each other through audio jack using minimodem, a general-purpose software audio FSK modem.

To install minimodem on pcDuino, we first need to install:

$sudo apt-get install pulseaudio
$sudo apt-get install pavucontrol
$sudo apt-get install audacity

Then we install minimodem using:

$sudo apt-get install minimodem

As we don’t have cross over audio cable in hand, so we use USB audio card as it breaks into audio out and line in, and we can cross over there, i.e., connect the transmitter’s audio out to the receiver’s audio in.

We will use volume control to select the USB audio card as the audio input and output devices.

In the transmitter side, we type “$minimodem –tx 100”, and it will wait for entries:

In the receiving side, we type “minimodem –rx 100”, and it will wait for incoming signal:

Now if we enter words in the transmitter side:

The receiver will receive them and display: