Key
01 - Altera DE2 Board (just assume it's an FPGA controlling 02 up to 15)
02 - LCD Module (Hitach HD44780U)
03 - PS/2 Port
04 - N/A
05 - 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 Keyboard
08 - DAC (component unknown)
09 - Signal Generator
10 - PCB (Transmitter board)
11 - Transmitting antenna
12 - Receiving antenna
13 - Envelope Detector
14 - 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?
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