Txt Msg DJ PCB Layout Design Narrative Team 22 John Doherty The Text Message DJ allows party guests the opportunity to choose which songs they want to hear. Guests can text the name of the sing they want and the Text message DJ streams the song from the internet. Other features include a voting process, strobing lights, and blacklists Everyone wants to dance to their favorite songs at a party, but rarely do guests have much say in song selections and playlists. The Text Message DJ aims to make song selection at a party a more democratic process. The Text Message DJ is a standalone unit that creates and maintains a party playlist based on song requests sent from party guests via SMS. Guests can send text messages containing song names and the Text Message DJ will automatically parse messages, sort requests, and play the most popular. In addition to playing the song audio, the Text Message DJ will strobe lights in sync with the beat of the currently playing song.

Block Diagram

PCB Considerations

PCB Considerations Overall Layout: GSM near side for antenna Sockets and power source must plug into back GSM near SIM to reduce potential to corrupt signal. Critical signals near micro (Reset, JTAG) Sensitive, fast switching digital logic signals separated UART for GSM UART for DMX Equalizer signal Separate digital com to micro do not cross Separate units blocked off All micro and gsm pins have headers

Micro Headers surround micro for easy access Decoupling capacitors close to micro Reset circuit close to micro Easy to access JTAG pins

Power Supply Considerations Three voltage requirements: 3.3V for micro and other digital logic 3.8V for GSM Module 5V for Raspberry Pi GSM Module draws up to 2A: This requires thicker traces Must be careful to keep away form more sensitive signals Add a ground pad to make wiring to ground easier All components have decoupling capacitors close to component