Guest Skyferia Posted March 26, 2013 Report Share Posted March 26, 2013 Key01 - Altera DE2 Board (just assume it's an FPGA controlling 02 up to 15)02 - LCD Module (Hitach HD44780U)03 - PS/2 Port04 - N/A05 - Expansion Header 01 (40 ports; 1x +5V output; 1x +3.3V output; 2x GND; 36 I/O ports)06 - Expansion Header 02 (40 ports; 1x +5V output; 1x +3.3V output; 2x GND; 36 I/O ports)07 - PC Keyboard08 - DAC (component unknown)09 - Signal Generator10 - PCB (Transmitter board)11 - Transmitting antenna12 - Receiving antenna13 - Envelope Detector14 - ADC (component unknown)15 - LCD Module (Hitach HD44780U)16 - PCB (Transmitter board)Basically when user keys in data using the PC keyboard (07), data is displayed on the LCD Module (02). When the Return/Enter key on the PC Keyboard is pressed, data is sent to the DAC(08)The output signal from the DAC (08) is sent through the transmitter(11) and received by the receiver(12).Signal is asynchronous Amplitude Shift Keying (ASK) (ASK due to transmitting ASCII data bits, or is there a better option?)The signal generator(09) inputs carrier signal. Frequency band is around 40~41 MHz.The received signal is sent to the Envelope Detector (13) which demodulates the ASK signal.The demodulated signal is passed through the ADC (14) and then the output data is sent to the LCD Module (15) to be displayed.Transmitting distance doesn't matter, lets assume from 15 centimeters to 3 meters. Questions:Is/are there any mistake(s) in the design? If none for the above, what is a good DAC and ADC to use? An op-amp, perhaps? What is a good and inexpensive component/device for both the transmitter and receiver to use? For the envelope detector, is a diode detector a good option? Any idea on how to power up the transmitter & receiver boards? Using an external power supply, regulated with a voltage/switching regulator a good option? Quote Link to comment Share on other sites More sharing options...
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