35 lines
1.4 KiB
Markdown
35 lines
1.4 KiB
Markdown
# Amplitude-Shift Keying
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| Attribute | Value |
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| ------------- | ---------------------------- |
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| UHF Band Name | LPD433, SRD860 (ISM) |
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| Carrier Freq. | 433 MHz, 868 MHz |
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| Bandwidth LPD | 1.7 MHz (433.05 - 434.79) |
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| Data Rate | 4 KHz, maybe more? |
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## General Notes
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- Generic 433 MHz RX/TX chips with ASK.
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- Transmitter is on if data pin is high. Receivers have
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automatic gain control. Will output random noise when
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there is no signal. Requires an error checking protocol.
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- Use manchester encoding and training preamble for receiver
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and transmitter to sync up their clock phases.
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- Encrypted serial connection over 433 MHz?
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## Planned Modules
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- Frequency-shift keying (FSK)
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- Phase-shift keying (PSK)
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- Chirp spread spectrum (CSS)
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## Further Links
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- [Line code](https://en.wikipedia.org/wiki/Line_code)
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- [Clock recovery](https://en.wikipedia.org/wiki/Clock_recovery)
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- [Manchester code](https://en.wikipedia.org/wiki/Manchester_code)
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- [Error correction code](https://en.wikipedia.org/wiki/Error_correction_code)
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- [Noisy-channel coding theorem](https://en.wikipedia.org/wiki/Noisy-channel_coding_theorem)
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- [Nyquist–Shannon sampling theorem](https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem)
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- [Short range device frequencies](https://de.wikipedia.org/wiki/Short_Range_Device#Frequenzen)
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