| #!/usr/bin/python2.6 |
| |
| # Copyright (C) 2014 The Android Open Source Project |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| """Interface for a USB-connected Monsoon power meter |
| (http://msoon.com/LabEquipment/PowerMonitor/). |
| This file requires gflags, which requires setuptools. |
| To install setuptools: sudo apt-get install python-setuptools |
| To install gflags, see http://code.google.com/p/python-gflags/ |
| To install pyserial, see http://pyserial.sourceforge.net/ |
| |
| Example usages: |
| Set the voltage of the device 7536 to 4.0V |
| python2.6 monsoon.py --voltage=4.0 --serialno 7536 |
| |
| Get 5000hz data from device number 7536, with unlimited number of samples |
| python2.6 monsoon.py --samples -1 --hz 5000 --serialno 7536 |
| |
| Get 200Hz data for 5 seconds (1000 events) from default device |
| python2.6 monsoon.py --samples 100 --hz 200 |
| |
| Get unlimited 200Hz data from device attached at /dev/ttyACM0 |
| python2.6 monsoon.py --samples -1 --hz 200 --device /dev/ttyACM0 |
| """ |
| |
| import fcntl |
| import os |
| import select |
| import signal |
| import stat |
| import struct |
| import sys |
| import time |
| import collections |
| |
| import gflags as flags # http://code.google.com/p/python-gflags/ |
| |
| import serial # http://pyserial.sourceforge.net/ |
| |
| FLAGS = flags.FLAGS |
| |
| class Monsoon: |
| """ |
| Provides a simple class to use the power meter, e.g. |
| mon = monsoon.Monsoon() |
| mon.SetVoltage(3.7) |
| mon.StartDataCollection() |
| mydata = [] |
| while len(mydata) < 1000: |
| mydata.extend(mon.CollectData()) |
| mon.StopDataCollection() |
| """ |
| |
| def __init__(self, device=None, serialno=None, wait=1): |
| """ |
| Establish a connection to a Monsoon. |
| By default, opens the first available port, waiting if none are ready. |
| A particular port can be specified with "device", or a particular Monsoon |
| can be specified with "serialno" (using the number printed on its back). |
| With wait=0, IOError is thrown if a device is not immediately available. |
| """ |
| |
| self._coarse_ref = self._fine_ref = self._coarse_zero = self._fine_zero = 0 |
| self._coarse_scale = self._fine_scale = 0 |
| self._last_seq = 0 |
| self.start_voltage = 0 |
| |
| if device: |
| self.ser = serial.Serial(device, timeout=1) |
| return |
| |
| while True: # try all /dev/ttyACM* until we find one we can use |
| for dev in os.listdir("/dev"): |
| if not dev.startswith("ttyACM"): continue |
| tmpname = "/tmp/monsoon.%s.%s" % (os.uname()[0], dev) |
| self._tempfile = open(tmpname, "w") |
| try: |
| os.chmod(tmpname, 0666) |
| except OSError: |
| pass |
| try: # use a lockfile to ensure exclusive access |
| fcntl.lockf(self._tempfile, fcntl.LOCK_EX | fcntl.LOCK_NB) |
| except IOError as e: |
| print >>sys.stderr, "device %s is in use" % dev |
| continue |
| |
| try: # try to open the device |
| self.ser = serial.Serial("/dev/%s" % dev, timeout=1) |
| self.StopDataCollection() # just in case |
| self._FlushInput() # discard stale input |
| status = self.GetStatus() |
| except Exception as e: |
| print >>sys.stderr, "error opening device %s: %s" % (dev, e) |
| continue |
| |
| if not status: |
| print >>sys.stderr, "no response from device %s" % dev |
| elif serialno and status["serialNumber"] != serialno: |
| print >>sys.stderr, ("Note: another device serial #%d seen on %s" % |
| (status["serialNumber"], dev)) |
| else: |
| self.start_voltage = status["voltage1"] |
| return |
| |
| self._tempfile = None |
| if not wait: raise IOError("No device found") |
| print >>sys.stderr, "waiting for device..." |
| time.sleep(1) |
| |
| |
| def GetStatus(self): |
| """ Requests and waits for status. Returns status dictionary. """ |
| |
| # status packet format |
| STATUS_FORMAT = ">BBBhhhHhhhHBBBxBbHBHHHHBbbHHBBBbbbbbbbbbBH" |
| STATUS_FIELDS = [ |
| "packetType", "firmwareVersion", "protocolVersion", |
| "mainFineCurrent", "usbFineCurrent", "auxFineCurrent", "voltage1", |
| "mainCoarseCurrent", "usbCoarseCurrent", "auxCoarseCurrent", "voltage2", |
| "outputVoltageSetting", "temperature", "status", "leds", |
| "mainFineResistor", "serialNumber", "sampleRate", |
| "dacCalLow", "dacCalHigh", |
| "powerUpCurrentLimit", "runTimeCurrentLimit", "powerUpTime", |
| "usbFineResistor", "auxFineResistor", |
| "initialUsbVoltage", "initialAuxVoltage", |
| "hardwareRevision", "temperatureLimit", "usbPassthroughMode", |
| "mainCoarseResistor", "usbCoarseResistor", "auxCoarseResistor", |
| "defMainFineResistor", "defUsbFineResistor", "defAuxFineResistor", |
| "defMainCoarseResistor", "defUsbCoarseResistor", "defAuxCoarseResistor", |
| "eventCode", "eventData", ] |
| |
| self._SendStruct("BBB", 0x01, 0x00, 0x00) |
| while True: # Keep reading, discarding non-status packets |
| bytes = self._ReadPacket() |
| if not bytes: return None |
| if len(bytes) != struct.calcsize(STATUS_FORMAT) or bytes[0] != "\x10": |
| print >>sys.stderr, "wanted status, dropped type=0x%02x, len=%d" % ( |
| ord(bytes[0]), len(bytes)) |
| continue |
| |
| status = dict(zip(STATUS_FIELDS, struct.unpack(STATUS_FORMAT, bytes))) |
| assert status["packetType"] == 0x10 |
| for k in status.keys(): |
| if k.endswith("VoltageSetting"): |
| status[k] = 2.0 + status[k] * 0.01 |
| elif k.endswith("FineCurrent"): |
| pass # needs calibration data |
| elif k.endswith("CoarseCurrent"): |
| pass # needs calibration data |
| elif k.startswith("voltage") or k.endswith("Voltage"): |
| status[k] = status[k] * 0.000125 |
| elif k.endswith("Resistor"): |
| status[k] = 0.05 + status[k] * 0.0001 |
| if k.startswith("aux") or k.startswith("defAux"): status[k] += 0.05 |
| elif k.endswith("CurrentLimit"): |
| status[k] = 8 * (1023 - status[k]) / 1023.0 |
| return status |
| |
| def RampVoltage(self, start, end): |
| v = start |
| if v < 3.0: v = 3.0 # protocol doesn't support lower than this |
| while (v < end): |
| self.SetVoltage(v) |
| v += .1 |
| time.sleep(.1) |
| self.SetVoltage(end) |
| |
| def SetVoltage(self, v): |
| """ Set the output voltage, 0 to disable. """ |
| if v == 0: |
| self._SendStruct("BBB", 0x01, 0x01, 0x00) |
| else: |
| self._SendStruct("BBB", 0x01, 0x01, int((v - 2.0) * 100)) |
| |
| |
| def SetMaxCurrent(self, i): |
| """Set the max output current.""" |
| assert i >= 0 and i <= 8 |
| |
| val = 1023 - int((i/8)*1023) |
| self._SendStruct("BBB", 0x01, 0x0a, val & 0xff) |
| self._SendStruct("BBB", 0x01, 0x0b, val >> 8) |
| |
| def SetUsbPassthrough(self, val): |
| """ Set the USB passthrough mode: 0 = off, 1 = on, 2 = auto. """ |
| self._SendStruct("BBB", 0x01, 0x10, val) |
| |
| |
| def StartDataCollection(self): |
| """ Tell the device to start collecting and sending measurement data. """ |
| self._SendStruct("BBB", 0x01, 0x1b, 0x01) # Mystery command |
| self._SendStruct("BBBBBBB", 0x02, 0xff, 0xff, 0xff, 0xff, 0x03, 0xe8) |
| |
| |
| def StopDataCollection(self): |
| """ Tell the device to stop collecting measurement data. """ |
| self._SendStruct("BB", 0x03, 0x00) # stop |
| |
| |
| def CollectData(self): |
| """ Return some current samples. Call StartDataCollection() first. """ |
| while True: # loop until we get data or a timeout |
| bytes = self._ReadPacket() |
| if not bytes: return None |
| if len(bytes) < 4 + 8 + 1 or bytes[0] < "\x20" or bytes[0] > "\x2F": |
| print >>sys.stderr, "wanted data, dropped type=0x%02x, len=%d" % ( |
| ord(bytes[0]), len(bytes)) |
| continue |
| |
| seq, type, x, y = struct.unpack("BBBB", bytes[:4]) |
| data = [struct.unpack(">hhhh", bytes[x:x+8]) |
| for x in range(4, len(bytes) - 8, 8)] |
| |
| if self._last_seq and seq & 0xF != (self._last_seq + 1) & 0xF: |
| print >>sys.stderr, "data sequence skipped, lost packet?" |
| self._last_seq = seq |
| |
| if type == 0: |
| if not self._coarse_scale or not self._fine_scale: |
| print >>sys.stderr, "waiting for calibration, dropped data packet" |
| continue |
| |
| out = [] |
| for main, usb, aux, voltage in data: |
| if main & 1: |
| out.append(((main & ~1) - self._coarse_zero) * self._coarse_scale) |
| else: |
| out.append((main - self._fine_zero) * self._fine_scale) |
| return out |
| |
| elif type == 1: |
| self._fine_zero = data[0][0] |
| self._coarse_zero = data[1][0] |
| # print >>sys.stderr, "zero calibration: fine 0x%04x, coarse 0x%04x" % ( |
| # self._fine_zero, self._coarse_zero) |
| |
| elif type == 2: |
| self._fine_ref = data[0][0] |
| self._coarse_ref = data[1][0] |
| # print >>sys.stderr, "ref calibration: fine 0x%04x, coarse 0x%04x" % ( |
| # self._fine_ref, self._coarse_ref) |
| |
| else: |
| print >>sys.stderr, "discarding data packet type=0x%02x" % type |
| continue |
| |
| if self._coarse_ref != self._coarse_zero: |
| self._coarse_scale = 2.88 / (self._coarse_ref - self._coarse_zero) |
| if self._fine_ref != self._fine_zero: |
| self._fine_scale = 0.0332 / (self._fine_ref - self._fine_zero) |
| |
| |
| def _SendStruct(self, fmt, *args): |
| """ Pack a struct (without length or checksum) and send it. """ |
| data = struct.pack(fmt, *args) |
| data_len = len(data) + 1 |
| checksum = (data_len + sum(struct.unpack("B" * len(data), data))) % 256 |
| out = struct.pack("B", data_len) + data + struct.pack("B", checksum) |
| self.ser.write(out) |
| |
| |
| def _ReadPacket(self): |
| """ Read a single data record as a string (without length or checksum). """ |
| len_char = self.ser.read(1) |
| if not len_char: |
| print >>sys.stderr, "timeout reading from serial port" |
| return None |
| |
| data_len = struct.unpack("B", len_char) |
| data_len = ord(len_char) |
| if not data_len: return "" |
| |
| result = self.ser.read(data_len) |
| if len(result) != data_len: return None |
| body = result[:-1] |
| checksum = (data_len + sum(struct.unpack("B" * len(body), body))) % 256 |
| if result[-1] != struct.pack("B", checksum): |
| print >>sys.stderr, "invalid checksum from serial port" |
| return None |
| return result[:-1] |
| |
| def _FlushInput(self): |
| """ Flush all read data until no more available. """ |
| self.ser.flush() |
| flushed = 0 |
| while True: |
| ready_r, ready_w, ready_x = select.select([self.ser], [], [self.ser], 0) |
| if len(ready_x) > 0: |
| print >>sys.stderr, "exception from serial port" |
| return None |
| elif len(ready_r) > 0: |
| flushed += 1 |
| self.ser.read(1) # This may cause underlying buffering. |
| self.ser.flush() # Flush the underlying buffer too. |
| else: |
| break |
| if flushed > 0: |
| print >>sys.stderr, "dropped >%d bytes" % flushed |
| |
| def main(argv): |
| """ Simple command-line interface for Monsoon.""" |
| useful_flags = ["voltage", "status", "usbpassthrough", "samples", "current"] |
| if not [f for f in useful_flags if FLAGS.get(f, None) is not None]: |
| print __doc__.strip() |
| print FLAGS.MainModuleHelp() |
| return |
| |
| if FLAGS.avg and FLAGS.avg < 0: |
| print "--avg must be greater than 0" |
| return |
| |
| mon = Monsoon(device=FLAGS.device, serialno=FLAGS.serialno) |
| |
| if FLAGS.voltage is not None: |
| if FLAGS.ramp is not None: |
| mon.RampVoltage(mon.start_voltage, FLAGS.voltage) |
| else: |
| mon.SetVoltage(FLAGS.voltage) |
| |
| if FLAGS.current is not None: |
| mon.SetMaxCurrent(FLAGS.current) |
| |
| if FLAGS.status: |
| items = sorted(mon.GetStatus().items()) |
| print "\n".join(["%s: %s" % item for item in items]) |
| |
| if FLAGS.usbpassthrough: |
| if FLAGS.usbpassthrough == 'off': |
| mon.SetUsbPassthrough(0) |
| elif FLAGS.usbpassthrough == 'on': |
| mon.SetUsbPassthrough(1) |
| elif FLAGS.usbpassthrough == 'auto': |
| mon.SetUsbPassthrough(2) |
| else: |
| sys.exit('bad passthrough flag: %s' % FLAGS.usbpassthrough) |
| |
| if FLAGS.samples: |
| # Make sure state is normal |
| mon.StopDataCollection() |
| status = mon.GetStatus() |
| native_hz = status["sampleRate"] * 1000 |
| |
| # Collect and average samples as specified |
| mon.StartDataCollection() |
| |
| # In case FLAGS.hz doesn't divide native_hz exactly, use this invariant: |
| # 'offset' = (consumed samples) * FLAGS.hz - (emitted samples) * native_hz |
| # This is the error accumulator in a variation of Bresenham's algorithm. |
| emitted = offset = 0 |
| collected = [] |
| history_deque = collections.deque() # past n samples for rolling average |
| |
| try: |
| last_flush = time.time() |
| while emitted < FLAGS.samples or FLAGS.samples == -1: |
| # The number of raw samples to consume before emitting the next output |
| need = (native_hz - offset + FLAGS.hz - 1) / FLAGS.hz |
| if need > len(collected): # still need more input samples |
| samples = mon.CollectData() |
| if not samples: break |
| collected.extend(samples) |
| else: |
| # Have enough data, generate output samples. |
| # Adjust for consuming 'need' input samples. |
| offset += need * FLAGS.hz |
| while offset >= native_hz: # maybe multiple, if FLAGS.hz > native_hz |
| this_sample = sum(collected[:need]) / need |
| |
| if FLAGS.timestamp: print int(time.time()), |
| |
| if FLAGS.avg: |
| history_deque.appendleft(this_sample) |
| if len(history_deque) > FLAGS.avg: history_deque.pop() |
| print "%f %f" % (this_sample, |
| sum(history_deque) / len(history_deque)) |
| else: |
| print "%f" % this_sample |
| sys.stdout.flush() |
| |
| offset -= native_hz |
| emitted += 1 # adjust for emitting 1 output sample |
| collected = collected[need:] |
| now = time.time() |
| if now - last_flush >= 0.99: # flush every second |
| sys.stdout.flush() |
| last_flush = now |
| except KeyboardInterrupt: |
| print >>sys.stderr, "interrupted" |
| |
| mon.StopDataCollection() |
| |
| |
| if __name__ == '__main__': |
| # Define flags here to avoid conflicts with people who use us as a library |
| flags.DEFINE_boolean("status", None, "Print power meter status") |
| flags.DEFINE_integer("avg", None, |
| "Also report average over last n data points") |
| flags.DEFINE_float("voltage", None, "Set output voltage (0 for off)") |
| flags.DEFINE_float("current", None, "Set max output current") |
| flags.DEFINE_string("usbpassthrough", None, "USB control (on, off, auto)") |
| flags.DEFINE_integer("samples", None, "Collect and print this many samples") |
| flags.DEFINE_integer("hz", 5000, "Print this many samples/sec") |
| flags.DEFINE_string("device", None, |
| "Path to the device in /dev/... (ex:/dev/ttyACM1)") |
| flags.DEFINE_integer("serialno", None, "Look for a device with this serial number") |
| flags.DEFINE_boolean("timestamp", None, |
| "Also print integer (seconds) timestamp on each line") |
| flags.DEFINE_boolean("ramp", True, "Gradually increase voltage") |
| |
| main(FLAGS(sys.argv)) |
