About SendString From Arduino to VoiceDevices

Ummmm...
I was a beginner, and now want to do some test

At few days ago, I buy a Voice Devices(Like this : TTL Serial Voice Player Module Mini Voice M3 Voice Music Player Single Chip Microcomputer - Free Shipping - ThanksBuyer),

It can install MicroSD,
I placed a music into the SD card and installed on the device.

But I try a long time cannot play the music.
I think the command "play,0001,$" is a String
So I want to Send String From Arduino to Voice Devices.

However... I don't know how can I do this from Arduino...
I want learn more skill
Thankyou :cry:

So I want to Send String From Arduino to Voice Devices.

How about

Serial.print("play,0001,$");

That will do it if the device is connected to serial port.
Of course in the setup function you need a

Serial.begin(baudRate);

Where baudRate is the baud rate that your device is expecting.