The Grove - Speaker is a module consist of power amplification and voice outputs. The loudness can be adjusted by the on-board potentiometer. With different input frequency, the loud-speaker generated different tones. Coding the music into arduino, DIY your own music box!
It is proximity ID card of 125KHz, EM4100. It has been specially manufactured and packaged to be clean from dust. And you can print any pictures on the PVC blank cards. You can use it with our RDM6300 RFID reader module.
The DHT-22 is a low cost humidity and temperature sensor with a single wire digital interface. The sensor is calibrated and doesn't require extra components so you can get right to measuring relative humidity and temperature.