Adafruit_GPIO/SPI.py
def read(self, length, assert_ss=True, deassert_ss=True):
        """Half-duplex SPI read.  If assert_ss is true, the SS line will be
        asserted low, the specified length of bytes will be clocked in the MISO
        line, and if deassert_ss is true the SS line will be put back high.
        Bytes which are read will be returned as a bytearray object.
        """
        if self._miso is None:
            raise RuntimeError('Read attempted with no MISO pin specified.')
        if assert_ss and self._ss is not None:
            self._gpio.set_low(self._ss)
        result = bytearray(length)
        for i in range(length):
            for j in range(8):
                # Flip clock off base.
                self._gpio.output(self._sclk, not self._clock_base)
                # Handle read on leading edge of clock.
                if self._read_leading:
                    if self._gpio.is_high(self._miso):
                        # Set bit to 1 at appropriate location.
                        result[i] |= self._read_shift(self._mask, j)
                    else:
                        # Set bit to 0 at appropriate location.
                        result[i] &= ~self._read_shift(self._mask, j)
                # Return clock to base.
                self._gpio.output(self._sclk, self._clock_base)
                # Handle read on trailing edge of clock.
                if not self._read_leading:
                    if self._gpio.is_high(self._miso):
                        # Set bit to 1 at appropriate location.
                        result[i] |= self._read_shift(self._mask, j)
                    else:
                        # Set bit to 0 at appropriate location.
                        result[i] &= ~self._read_shift(self._mask, j)
        if deassert_ss and self._ss is not None:
            self._gpio.set_high(self._ss)
        return result
def read(self, length, assert_ss=True, deassert_ss=True):
        """Half-duplex SPI read.  If assert_ss is true, the SS line will be
        asserted low, the specified length of bytes will be clocked in the MISO
        line, and if deassert_ss is true the SS line will be put back high.
        Bytes which are read will be returned as a bytearray object.
        """
        if self._miso is None:
            raise RuntimeError('Read attempted with no MISO pin specified.')
        if assert_ss and self._ss is not None:
            self._gpio.set_low(self._ss)
        result = bytearray(length)
        for i in range(length):
            for j in range(8):
                # Flip clock off base.
                self._gpio.output(self._sclk, not self._clock_base)
                # Handle read on leading edge of clock.
                if self._read_leading:
                    if self._gpio.is_high(self._miso):
                        # Set bit to 1 at appropriate location.
                        result[i] |= self._read_shift(self._mask, j)
                    else:
                        # Set bit to 0 at appropriate location.
                        result[i] &= ~self._read_shift(self._mask, j)
                # Return clock to base.
                self._gpio.output(self._sclk, self._clock_base)
                # Handle read on trailing edge of clock.
                if not self._read_leading:
                    if self._gpio.is_high(self._miso):
                        # Set bit to 1 at appropriate location.
                        result[i] |= self._read_shift(self._mask, j)
                    else:
                        # Set bit to 0 at appropriate location.
                        result[i] &= ~self._read_shift(self._mask, j)
        if deassert_ss and self._ss is not None:
            self._gpio.set_high(self._ss)
        return result
def read ( self , length , assert_ss = True , deassert_ss = True ) : if self . _miso is None : raise RuntimeError ( 'Read attempted with no MISO pin specified.' ) if assert_ss and self . _ss is not None : self . _gpio . set_low ( self . _ss ) result = bytearray ( length ) for i in range ( length ) : for j in range ( 8 ) : # Flip clock off base. self . _gpio . output ( self . _sclk , not self . _clock_base ) # Handle read on leading edge of clock. if self . _read_leading : if self . _gpio . is_high ( self . _miso ) : # Set bit to 1 at appropriate location. result [ i ] |= self . _read_shift ( self . _mask , j ) else : # Set bit to 0 at appropriate location. result [ i ] &= ~ self . _read_shift ( self . _mask , j ) # Return clock to base. self . _gpio . output ( self . _sclk , self . _clock_base ) # Handle read on trailing edge of clock. if not self . _read_leading : if self . _gpio . is_high ( self . _miso ) : # Set bit to 1 at appropriate location. result [ i ] |= self . _read_shift ( self . _mask , j ) else : # Set bit to 0 at appropriate location. result [ i ] &= ~ self . _read_shift ( self . _mask , j ) if deassert_ss and self . _ss is not None : self . _gpio . set_high ( self . _ss ) return result
Half-duplex SPI read.  If assert_ss is true, the SS line will be
        asserted low, the specified length of bytes will be clocked in the MISO
        line, and if deassert_ss is true the SS line will be put back high.
        Bytes which are read will be returned as a bytearray object.
Half - duplex SPI read . If assert_ss is true the SS line will be asserted low the specified length of bytes will be clocked in the MISO line and if deassert_ss is true the SS line will be put back high . Bytes which are read will be returned as a bytearray object .