Source code for pynq.lib.button

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import asyncio
from pynq import MMIO
from pynq import PL
from pynq import Interrupt


__author__ = "Giuseppe Natale"
__copyright__ = "Copyright 2016, Xilinx"
__email__ = "pynq_support@xilinx.com"


[docs]class Button(object): """This class controls the onboard push-buttons. Attributes ---------- index : int Index of the push-buttons, starting from 0. """ _mmio = None def __init__(self, index): """Create a new Button object. Parameters ---------- index : int The index of the push-buttons, from 0 to 3. """ if Button._mmio is None: base_addr = PL.ip_dict["btns_gpio"]["phys_addr"] Button._mmio = MMIO(base_addr, 512) self.index = index self.interrupt = None try: self.interrupt = Interrupt('btns_gpio/ip2intc_irpt') # Enable interrupts Button._mmio.write(0x11C, 0x80000000) Button._mmio.write(0x128, 0x00000001) except ValueError: pass
[docs] def read(self): """Read the current value of the button. Returns ------- int Either 1 if the button is pressed or 0 otherwise """ curr_val = Button._mmio.read() return (curr_val & (1 << self.index)) >> self.index
[docs] @asyncio.coroutine def wait_for_value_async(self, value): """Wait for the button to be pressed or released Parameters ---------- value: int 1 to wait for press or 0 to wait for release This function is an asyncio coroutine """ if self.interrupt is None: raise RuntimeError('Interrupts not available in this Overlay') while self.read() != value: yield from self.interrupt.wait() if Button._mmio.read(0x120) & 0x1: Button._mmio.write(0x120, 0x00000001)
[docs] def wait_for_value(self, value): """Wait for the button to be pressed or released Parameters ---------- value: int 1 to wait for press or 0 to wait for release This function wraps the coroutine form so the asyncio event loop will run until the function returns """ if self.interrupt is None: raise RuntimeError('Interrupts not available in this Overlay') loop = asyncio.get_event_loop() loop.run_until_complete(asyncio.ensure_future( self.wait_for_value_async(value) ))