mirror of https://github.com/joan2937/pigpio
29 lines
1.1 KiB
Markdown
29 lines
1.1 KiB
Markdown
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# Python Class for Reading Single Edge Nibble Transmission (SENT) using the Raspberry Pi
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A full description of this Python script is described at [www.surfncircuits.com](https://surfncircuits.com) in the blog entry: [Implementing a Single Edge Nibble Transmission (SENT) protocol in Python for the Raspberry Pi Zero](https://surfncircuits.com/?p=3725)
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This python library will read a Raspberry Pi GPIO pin connected. Start the pigpiod daemon with one microsecond sampling to read SENT transmissions with three microsecond tick times.
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## To start the daemon on Raspberry Pi
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- sudo pigpiod -s 1
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## SENT packet frame summary
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- Sync Pulse: 56 ticks
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- 4 bit Status and Message Pulse: 17-32 ticks
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- 4 bit (9:12) Data1 Field: 17-32 ticks
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- 4 bit (5:8) Data1 Field: 17-32 ticks
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- 4 bit (1:4) Data1 Field: 17-32 ticks
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- 4 bit (9-12) Data2 Field: 17-32 ticks
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- 4 bit (5-8) Data2 Field: 17-32 ticks
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- 4 bit (1-4) Data2 Field: 17-32 ticks
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- 4 bit CRC: 17-32 ticks
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## requirements
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[pigpiod](http://abyz.me.uk/rpi/pigpio/) library required
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## To run the script for a signal attached to GPIO BCD 18 (pin 12)
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- python3 sent_READ.py
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