import time
from typing import Optional
from tbot.machine import linux
[docs]class Gpio:
def __init__(
self,
host: linux.LinuxShell,
gpio_number: int,
*,
sys_path: Optional[linux.Path] = None,
):
"""Initialize GPIO
Raspberry Pi Model 2 and above use as gpio_number their BCM GPIO Numbers
:param linux.LinuxShell host: Linux Shell
:param int gpio_number: GPIO Number
:param linux.Path sys_path: Path to the ``/sys/`` mountpoint if it differs
from the default.
.. versionchanged:: 0.10.6
Added the ``sys_path`` parameter.
"""
self.host = host
self.gpio_number = gpio_number
if sys_path is None:
sys_path = self.host.fsroot / "sys"
self._gpio_sysclass_path = sys_path / "class" / "gpio"
self._gpio_path = self._gpio_sysclass_path / f"gpio{self.gpio_number}"
self._export()
self._direction = self.get_direction()
def _export(self) -> None:
"""Exports GPIO"""
if not self._gpio_path.is_dir():
(self._gpio_sysclass_path / "export").write_text(str(self.gpio_number))
[docs] def set_direction(self, direction: str) -> None:
"""Set Direction
Sets direction to ``in`` or ``out``
:param str direction: Direction to set
"""
assert direction in ["in", "out"], f"Unsupported GPIO direction: {direction!r}"
if self._direction == direction:
return
(self._gpio_path / "direction").write_text(direction)
self._direction = direction
[docs] def set_active_low(self, value: bool) -> None:
"""Set Active Low
When Active Low is ``True``, the GPIO triggers on a ``LOW`` singnal, else on a ``HIGH`` signal
:param bool value: Value
"""
(self._gpio_path / "active_low").write_text("1" if value else "0")
[docs] def get_active_low(self) -> bool:
"""Get Active Low
Reads value and returns direction ``in`` or ``out``
:rtype: bool
:returns: Value
"""
return (self._gpio_path / "active_low").read_text().strip() != "0"
[docs] def get_direction(self) -> str:
"""Get Direction of GPIO
Reads direction and returns direction ``in`` or ``out``
:rtype: str
:returns: Value
"""
return (self._gpio_path / "direction").read_text().strip()
[docs] def set_value(self, value: bool) -> None:
"""Set Value
Sets value to ``HIGH`` and ``LOW``
:param bool value: Value to set
"""
if self._direction == "in":
raise Exception("Can't set a GPIO which is not an output")
(self._gpio_path / "value").write_text("1" if value else "0")
[docs] def get_value(self) -> bool:
"""Get Value
Reads value and returns value ``True`` or ``False``
:rtype: bool
:returns: Value
"""
if not (self._direction == "in"):
raise Exception("Can't get a value from a GPIO which is not an input")
return (self._gpio_path / "value").read_text().strip() != "0"
[docs] def pulse(self, on_time: float, off_time: Optional[float] = None) -> None:
"""Toggle GPIO
Toggles GPIO Pin between ``HIGH`` and ``LOW``
:param float on_time: Time GPIO is ``HIGH``
:param float off_time: Time GPIO is ``LOW``. Defaults to ``on_time``
.. versionadded:: 0.10.6
"""
if off_time is None:
off_time = on_time
self.set_value(True)
time.sleep(on_time)
self.set_value(False)
time.sleep(off_time)
