code: def _i2c_start(self):
          
          # Set SCL high and SDA low, repeat 4 times to stay in this state for a
          # short period of time.
          self._ft232h.output_pins({0: GPIO.HIGH, 1: GPIO.LOW}, write=False)
          self._command.append(self._ft232h.mpsse_gpio() * _REPEAT_DELAY)
          # Now drop SCL to low (again repeat 4 times for short delay).
          self._ft232h.output_pins({0: GPIO.LOW, 1: GPIO.LOW}, write=False)
          self._command.append(self._ft232h.mpsse_gpio() * _REPEAT_DELAY)
docs: Send I2C start signal. Must be called within a transaction start/end.