Desk Phone Mic & Sampler - Custom 1 ECE342-W22
By
The Desk Phone Microphone & Sampler is a USB-compatible device meant for public address and live performance. While connected to a USB device (likely a computer) and while in either of the two keyboard modes, pressing buttons on the dialpad will send specific character signals: Mode 1 signals are [1 2 3 4 5 6 7 8 9 0] and Mode 2 signals are [z x c v b n m ,] These keypresses work with a DJ software, Serato DJ Pro, to jump to a specific time point in a song (Mode 1), and play sound samples (Mode 2). A red LED at the bottom-right corner of the desk phone indicates the mode. Slow blinking indicates Mode 1, while fast blinking indicates Mode 2. Mode 3 is indicated by a continuously lit LED. Pressing 6 on the dialpad will put the device in Mode 1, pressing # on the dialpad will put the device in Mode 2, and pressing FLASH will put the device in Mode 3. The corded phone serves as a PA microphone. Picking it up off the dock unmutes it. Sliding a switch on the side turns on a voice modulator that creates a strobe effect, accomplished with a 555-MOSFET. While in Mode 3, pressing buttons starts recording from the microphone, stops recording, overwrites, and plays the recording back through the final output. The final output signal is delivered through a mono audio connection, with a 1/4" TS male jack. This signal has a voltage less than 100mV peak-to-peak with negligible DC offset. Future Improvement Ideas: --Reduce signal noise in Mode 3 --Increase I/O of Arduino using shift register, scanning array PCB, and code --Additional choices for voice modulation --LCD to indicate mode and current action --Multiple RGB LEDs