This DTMF Shield is a Dual-tone multi-frequency signaling module decoder for Arduino With it's audio connector you can decode the crazy funny noises common phones make.

Play your .mp3 files stored by USB or SD card. For Use (12V): Place a 68Ohm/1W Resistor in series with the (+) of the Power Supply, to avoid excessive dissipation.

The Grove - Speaker is a module consisting of power amplification and voice outputs. The volume can be adjusted by the integrated potentiometer . With input frequencies at different, the speaker generates different tones. Encoding the music in Arduino, make your own music box yourself!

The Vma449 integrates the Voice Recorder ISD1820 and Playback CI to record a single message up to 20 seconds long. The recorded message is stored in the analog flash memory that keeps the message stored even in the event of a power failure. The module has an integrated microphone to record your message and buttons for recording, partial playback or full reproduction of the message functions.

The purpose of this sensor is to measure the sound intensity of the surrounding environment.