pynq.iop.arduino_analog — Python productivity for Zynq (Pynq) v1.0

# Source code for pynq.iop.arduino_analog

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    __author__      = "Yun Rock Qu"
    __copyright__   = "Copyright 2016, Xilinx"
    __email__       = "pynq_support@xilinx.com"

    import time
    import struct
    from pynq import MMIO
    from pynq.iop import request_iop
    from pynq.iop import iop_const
    from pynq.iop import ARDUINO

    ARDUINO_ANALOG_PROGRAM = "arduino_analog.bin"
    ARDUINO_ANALOG_LOG_START = iop_const.MAILBOX_OFFSET+16
    ARDUINO_ANALOG_SAMPLES = 1000

    class Arduino_Analog(object):
        """This class controls the Arduino Analog.

        XADC is an internal analog controller in the hardware. This class
        provides API to do analog reads from IOP.

        Attributes
        ----------
        iop : _IOP
            I/O processor instance used by Arduino_Analog class.
        mmio : MMIO
            Memory-mapped I/O instance to read and write instructions and data.
        log_running : int
            The state of the log (0: stopped, 1: started).
        log_interval_ms : int
            Time in milliseconds between samples on the same channel.
        gr_pin : list
            A list of analog pins getting sampled.
        num_channels : int
            The number of channels sampled.

        """
        def __init__(self, if_id, gr_pin):
            """Return a new instance of an Arduino_Analog object.

            Note
            ----
            The parameter `gr_pin` is a list of analog pins enabled.

            Parameters
            ----------
            if_id : int
                The interface ID (3) corresponding to (ARDUINO).
            gr_pin: list
                A group of pins for arduino analog pins.

            """
            if if_id in [ARDUINO]:
                for pin in gr_pin:
                    if not pin in range(6):
                        raise ValueError("Analog pin number can only be 0 - 5.")
            else:
                raise ValueError("No such IOP for analog device.")

            self.iop = request_iop(if_id, ARDUINO_ANALOG_PROGRAM)
            self.mmio = self.iop.mmio
            self.log_interval_ms = 1000
            self.log_running  = 0
            self.gr_pin = gr_pin
            self.num_channels = len(gr_pin)
            self.iop.start()

            # Enable all the analog pins
            self.mmio.write(iop_const.MAILBOX_OFFSET, 0)
            self.mmio.write(iop_const.MAILBOX_OFFSET+0x04, 0)
            self.mmio.write(iop_const.MAILBOX_OFFSET+0x08, 0)
            self.mmio.write(iop_const.MAILBOX_OFFSET+0x0C, 0)
            self.mmio.write(iop_const.MAILBOX_OFFSET+0x10, 0)
            self.mmio.write(iop_const.MAILBOX_OFFSET+0x14, 0)

            # Write configuration and wait for ACK
            self.mmio.write(iop_const.MAILBOX_OFFSET + \
                            iop_const.MAILBOX_PY2IOP_CMD_OFFSET, 0x1)
            while (self.mmio.read(iop_const.MAILBOX_OFFSET + \
                                  iop_const.MAILBOX_PY2IOP_CMD_OFFSET) == 0x1):
                pass

        def read_raw(self):
            """Read the analog raw value from the analog peripheral.

            Parameters
            ----------
            None

            Returns
            -------
            list
                The raw values from the analog device.

            """
            data_channels = 0
            for channel in self.gr_pin:
                data_channels |= (0x1<<channel)
            cmd = (data_channels << 8) + 0x3
            self.mmio.write(iop_const.MAILBOX_OFFSET+ \
                            iop_const.MAILBOX_PY2IOP_CMD_OFFSET, cmd)
            while not (self.mmio.read(iop_const.MAILBOX_OFFSET + \
                                      iop_const.MAILBOX_PY2IOP_CMD_OFFSET) == 0):
                pass

            value = []
            for i in range(self.num_channels):
                value.append(self.mmio.read(iop_const.MAILBOX_OFFSET+4*i))
            return value

        def read(self):
            """Read the voltage value from the analog peripheral.

            Parameters
            ----------
            None

            Returns
            -------
            list
                The float values after translation.

            """
            data_channels = 0
            for channel in self.gr_pin:
                data_channels |= (0x1<<channel)
            cmd = (data_channels << 8) + 0x5
            self.mmio.write(iop_const.MAILBOX_OFFSET + \
                            iop_const.MAILBOX_PY2IOP_CMD_OFFSET, cmd)
            while not (self.mmio.read(iop_const.MAILBOX_OFFSET + \
                                      iop_const.MAILBOX_PY2IOP_CMD_OFFSET) == 0):
                pass

            value = []
            for i in range(self.num_channels):
                value.append(float("{0:.4f}".format(self._reg2float(
                                self.mmio.read(iop_const.MAILBOX_OFFSET+4*i)))))
            return value

        def set_log_interval_ms(self, log_interval_ms):
            """Set the length of the log for the analog peripheral.

            This method can set the time interval between two samples, so that
            users can read out multiple values in a single log.

            Parameters
            ----------
            log_interval_ms : int
                The time between two samples in milliseconds, for logging only.

            Returns
            -------
            None

            """
            if (log_interval_ms < 0):
                raise ValueError("Time between samples should be no less than 0.")

            self.log_interval_ms = log_interval_ms
            self.mmio.write(iop_const.MAILBOX_OFFSET+4, self.log_interval_ms)

        def start_log_raw(self):
            """Start recording raw data in a log.

            This method will first call set_log_interval_ms() before writting to
            the MMIO.

            Parameters
            ----------
            None

            Returns
            -------
            None

            """
            self.log_running = 1
            self.set_log_interval_ms(self.log_interval_ms)

            data_channels = 0
            for channel in self.gr_pin:
                data_channels |= (0x1<<channel)
            cmd = (data_channels << 8) + 0x7
            self.mmio.write(iop_const.MAILBOX_OFFSET + \
                            iop_const.MAILBOX_PY2IOP_CMD_OFFSET, cmd)

        def start_log(self):
            """Start recording multiple voltage values (float) in a log.

            This method will first call set_log_interval_ms() before writting to
            the MMIO.

            Parameters
            ----------
            None

            Returns
            -------
            None

            """
            self.log_running = 1
            self.set_log_interval_ms(self.log_interval_ms)

            data_channels = 0
            for channel in self.gr_pin:
                data_channels |= (0x1<<channel)
            cmd = (data_channels << 8) + 0x9
            self.mmio.write(iop_const.MAILBOX_OFFSET + \
                            iop_const.MAILBOX_PY2IOP_CMD_OFFSET, cmd)

        def stop_log_raw(self):
            """Stop recording the raw values in the log.

            Simply write 0xC to the MMIO to stop the log.

            Parameters
            ----------
            None

            Returns
            -------
            None

            """
            if(self.log_running == 1):
                self.mmio.write(iop_const.MAILBOX_OFFSET+ \
                                iop_const.MAILBOX_PY2IOP_CMD_OFFSET, 0xB)
                self.log_running = 0
            else:
                raise RuntimeError("No analog log running.")

        def stop_log(self):
            """Stop recording the voltage values in the log.

            This can be done by calling the stop_log_raw() method.

            Parameters
            ----------
            None

            Returns
            -------
            None

            """
            if(self.log_running == 1):
                self.mmio.write(iop_const.MAILBOX_OFFSET+ \
                                iop_const.MAILBOX_PY2IOP_CMD_OFFSET, 0xB)
                self.log_running = 0
            else:
                raise RuntimeError("No analog log running.")

        def get_log_raw(self):
            """Return list of logged raw samples.

            Parameters
            ----------
            None

            Returns
            -------
            list
                List of valid raw samples from the analog device.

            """
            # Stop logging
            self.stop_log()

            # Prep iterators and results list
            head_ptr = self.mmio.read(iop_const.MAILBOX_OFFSET+0x8)
            tail_ptr = self.mmio.read(iop_const.MAILBOX_OFFSET+0xC)
            readings = []
            for i in range(self.num_channels):
                readings.append([])

            # Calculate the log ending
            log_end = ARDUINO_ANALOG_LOG_START + \
                      4*ARDUINO_ANALOG_SAMPLES*self.num_channels

            # Sweep circular buffer for samples
            if head_ptr == tail_ptr:
                return None
            elif head_ptr < tail_ptr:
                for i in range(head_ptr,tail_ptr,4*self.num_channels):
                    for j in range(self.num_channels):
                        readings[j].append(self.mmio.read(i+4*j))
            else:
                for i in range(head_ptr,log_end,4*self.num_channels):
                    for j in range(self.num_channels):
                        readings[j].append(self.mmio.read(i+4*j))
                for i in range(ARDUINO_ANALOG_LOG_START,tail_ptr,
                               4*self.num_channels):
                    for j in range(self.num_channels):
                        readings[j].append(self.mmio.read(i+4*j))
            return readings

        def get_log(self):
            """Return list of logged samples.

            Parameters
            ----------
            None

            Returns
            -------
            list
                List of valid voltage samples (floats) from the ADC sensor.

            """
            # Stop logging
            self.stop_log()

            # Prep iterators and results list
            head_ptr = self.mmio.read(iop_const.MAILBOX_OFFSET+0x8)
            tail_ptr = self.mmio.read(iop_const.MAILBOX_OFFSET+0xC)
            readings = []
            for i in range(self.num_channels):
                readings.append([])

            # Calculate the log ending
            log_end = ARDUINO_ANALOG_LOG_START + \
                      4*ARDUINO_ANALOG_SAMPLES*self.num_channels

            # Sweep circular buffer for samples
            if head_ptr == tail_ptr:
                return None
            elif head_ptr < tail_ptr:
                for i in range(head_ptr,tail_ptr,4*self.num_channels):
                    for j in range(self.num_channels):
                        readings[j].append(float("{0:.4f}".format(
                                        self._reg2float(self.mmio.read(i+4*j)))))
            else:
                for i in range(head_ptr,log_end,4*self.num_channels):
                    for j in range(self.num_channels):
                        readings[j].append(float("{0:.4f}".format(
                                        self._reg2float(self.mmio.read(i+4*j)))))
                for i in range(ARDUINO_ANALOG_LOG_START,tail_ptr,
                               4*self.num_channels):
                    for j in range(self.num_channels):
                        readings[j].append(float("{0:.4f}".format(
                                        self._reg2float(self.mmio.read(i+4*j)))))
            return readings

        def reset(self):
            """Resets the system monitor for analog devices.

            Parameters
            ----------
            None

            Returns
            -------
            None

            """
            self.mmio.write(iop_const.MAILBOX_OFFSET + \
                            iop_const.MAILBOX_PY2IOP_CMD_OFFSET, 0xB)
            while (self.mmio.read(iop_const.MAILBOX_OFFSET + \
                                    iop_const.MAILBOX_PY2IOP_CMD_OFFSET) == 0xB):
                pass

        def _reg2float(self, reg):
            """Converts 32-bit register value to floats in Python.

            Parameters
            ----------
            reg: int
                A 32-bit register value read from the mailbox.

            Returns
            -------
            float
                A float number translated from the register value.

            """
            s = struct.pack('>l', reg)
            return struct.unpack('>f', s)[0]