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https://github.com/KevinMidboe/python-gpiozero.git
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7429c03117
Big push on getting the docs cleaned up before 1.0. Proper wrapping of everything so it's decently viewable from the command line (or as decently viewable as markdown can be - the tables will never look great from the command line). Only one code change in this PR: rename bouncetime to bounce_time (everything else is PEP-8, so this probably should be too) and change its units to seconds from milliseconds (again, all other durations in the library are in seconds, so it feels inconsistent that this one isn't; for the sake of those who won't read the docs - which is most people - I figure consistency helps with guessing!).
90 lines
2.2 KiB
Markdown
90 lines
2.2 KiB
Markdown
# Notes
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1. **BCM pin numbering**
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This library uses Broadcom (BCM) pin numbering for the GPIO pins, as
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opposed to BOARD. Unlike the `RPi.GPIO` library, this is not configurable.
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Any pin marked `GPIO` can be used for generic components.
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The BCM pin layout is as follows:
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|-----------:|:-----------|
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| 3V3 | 5V |
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| **GPIO2** | 5V |
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| **GPIO3** | GND |
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| **GPIO4** | **GPIO14** |
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| GND | **GPIO15** |
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| **GPIO17** | **GPIO18** |
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| **GPIO27** | GND |
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| **GPIO22** | **GPIO23** |
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| 3V3 | **GPIO24** |
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| **GPIO10** | GND |
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| **GPIO9** | **GPIO25** |
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| **GPIO11** | **GPIO8** |
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| GND | **GPIO7** |
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| DNC | DNC |
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| **GPIO5** | GND |
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| **GPIO6** | **GPIO12** |
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| **GPIO13** | GND |
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| **GPIO19** | **GPIO16** |
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| **GPIO26** | **GPIO20** |
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| GND | **GPIO21** |
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- *GND = Ground*
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- *3V3 = 3.3 Volts*
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- *5V = 5 Volts*
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- *DNC = Do not connect (special use pins)*
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2. **Wiring**
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All components must be wired up correctly before using with this library.
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3. **Keep your program alive with `signal.pause`**
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The following program looks like it should turn an LED on:
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```python
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from gpiozero import led
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led = LED(2)
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led.on()
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```
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And it does, if you're using the Python shell, IPython shell or IDLE shell,
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but if you saved this program as a Python file and ran it, it would flash
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on for a moment then the program would end and it would turn off.
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The following file includes an intentional `pause` to keep the program
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alive:
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```python
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from gpiozero import LED
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from signal import pause
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led = LED(2)
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led.on()
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pause()
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```
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Now running the program will stay running, leaving the LED on, until it is
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forced to quit.
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Similarly, when setting up callbacks on button presses or other input
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devices, the program needs to be running for the events to be detected:
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```python
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from gpiozero import Button
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from signal import pause
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button = Button(2)
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button.when_pressed = lambda: print("Button was pressed!")
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pause()
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```
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