class I2CBus(AbstractBus):
"""Initialize the I2C hardware driver and represent as bus object."""
type = BusType.I2C
frequency = 100000
def start(self):
""" """
# Todo: Improve error handling.
try:
if self.platform_info.vendor == self.platform_info.MICROPYTHON.Vanilla:
from machine import I2C
self.adapter = I2C(self.number,
sda=Pin(int(self.pins['sda'][1:])),
scl=Pin(int(self.pins['scl'][1:])),
freq=self.frequency)
elif self.platform_info.vendor == self.platform_info.MICROPYTHON.Pycom:
from machine import I2C
self.adapter = I2C(self.number,
mode=I2C.MASTER,
pins=(self.pins['sda'], self.pins['scl']),
baudrate=self.frequency)
elif self.platform_info.vendor == self.platform_info.MICROPYTHON.Odroid:
from smbus2 import SMBus
self.adapter = SMBus(self.number)
elif self.platform_info.vendor == self.platform_info.MICROPYTHON.RaspberryPi:
import board
import busio
def i2c_add_bus(busnum, scl, sda):
"""
Register more I2C buses with Adafruit Blinka.
Make Adafruit Blinka learn another I2C bus.
Please make sure you define it within /boot/config.txt like::
dtoverlay=i2c-gpio,bus=3,i2c_gpio_delay_us=1,i2c_gpio_sda=26,i2c_gpio_scl=20
"""
# Uncache this module, otherwise monkeypatching will fail on subsequent calls.
import sys
try:
del sys.modules['microcontroller.pin']
except:
pass
# Monkeypatch "board.pin.i2cPorts".
i2c_port = (busnum, scl, sda)
if i2c_port not in board.pin.i2cPorts:
board.pin.i2cPorts += (i2c_port, )
pin_scl = self.pins['scl']
pin_sda = self.pins['sda']
# When I2C port pins are defined as Integers, register them first.
if isinstance(pin_scl, int):
i2c_add_bus(self.number, pin_scl, pin_sda)
SCL = board.pin.Pin(pin_scl)
SDA = board.pin.Pin(pin_sda)
# When I2C port pins are defined as Strings and start with "board.",
# they are probably already Pin aliases of Adafruit Blinka.
elif isinstance(pin_scl, str) and pin_scl.startswith('board.'):
SCL = eval(pin_scl)
SDA = eval(pin_sda)
self.adapter = busio.I2C(SCL, SDA)
else:
raise NotImplementedError(
'I2C bus is not implemented on this platform')
self.just_started = True
if not self.platform_info.vendor == self.platform_info.MICROPYTHON.Odroid:
self.scan_devices()
if self.platform_info.vendor == self.platform_info.MICROPYTHON.Odroid:
self.devices = self.scan_devices_smbus2()
log.info("Scan I2C bus via smbus2 for devices...")
log.info("Found {} I2C devices: {}.".format(
len(self.devices), self.devices))
self.ready = True
except Exception as ex:
#log.exc(ex, 'I2C hardware driver failed')
raise
def scan_devices(self):
log.info('Scan I2C with id={} bus for devices...'.format(self.number))
self.devices = self.adapter.scan()
# i2c.readfrom(0x76, 5)
log.info("Found {} I2C devices: {}".format(len(self.devices),
self.devices))
def scan_devices_smbus2(self, start=0x03, end=0x78):
try:
list = []
for i in range(start, end):
val = 1
try:
self.adapter.read_byte(i)
except OSError as e:
val = e.args[0]
finally:
if val != 5: # No device
if val == 1:
res = "Available"
elif val == 16:
res = "Busy"
elif val == 110:
res = "Timeout"
else:
res = "Error code: " + str(val)
# print(hex(i) + " -> " + res)
if res == 'Available':
# print(i)
list.append(i)
return list
except Exception as exp:
log.exc(exp, 'scan smbus2 failed')
def power_on(self):
"""
Turn on the I2C peripheral after power off.
"""
# Don't reinitialize device if power on just occurred through initial driver setup.
if self.just_started:
self.just_started = False
return
# uPy doesn't have deinit so it doesn't need init
if self.platform_info.vendor == self.platform_info.MICROPYTHON.Pycom:
from machine import I2C
self.adapter.init(mode=I2C.MASTER, baudrate=self.frequency)
def power_off(self):
"""
Turn off the I2C peripheral.
https://docs.pycom.io/firmwareapi/pycom/machine/i2c.html
"""
log.info('Turning off I2C bus {}'.format(self.name))
if self.platform_info.vendor == self.platform_info.MICROPYTHON.Pycom:
self.adapter.deinit()
class Host:
'''Class to interact with FPGA
'''
def __init__(self, platform=None):
''' platform -- object which has gateware settings
only passed to controller if virtual
test is executed. Needed in lasers.py
as each test here has a slightly
different TestPlatform
'''
# case raspberry
if platform is None:
self.test = False
from gpiozero import LED
import spidev
from smbus2 import SMBus
self.platform = Firestarter(micropython=False)
# IC bus used to set power laser
self.bus = SMBus(self.platform.ic_dev_nr)
# SPI to sent data to scanner
self.spi = spidev.SpiDev()
self.spi.open(*self.platform.spi_dev)
self.spi.mode = 1
self.spi.max_speed_hz = round(1E6)
self.chip_select = LED(self.platform.chip_select)
# programs TMC2130
self.init_steppers()
# stepper motor enable pin
self.enable = LED(self.platform.enable_pin)
# case micropython:
elif upython:
self.test = False
import machine
self.platform = platformmicro(micropython=True)
# IC bus
self.bus = machine.I2C(self.platform.ic_dev_nr)
self.bus.init(machine.I2C.CONTROLLER, adr=self.platform.ic_addr)
# SPI
# spi port is hispi
self.spi = machine.SPI(self.spi_dev, baudrate=round(1E6))
self.chip_select = machine.Pin(self.platform.chip_select)
# program TMC2130
# TODO: add TMC2130 library to micropython
# self.init_steppers()
# stepper motor enable pin
self.enable = machine.Pin(self.platform.enable_pin)
else:
self.platform = platform
self.test = True
# maximum number of times tried to write to FIFO
# if memoery is full
self.maxtrials = 10 if self.test else 1E5
self.laser_params = params(self.platform)
self._position = np.array([0]*self.platform.motors, dtype='float64')
def init_steppers(self):
'''configure TMC2130 steppers via SPI
Uses teemuatflut CPP library with custom python wrapper
https://github.com/hstarmans/TMCStepper
'''
import steppers
self.motors = [steppers.TMC2130(link_index=i)
for i in range(1, 1+self.platform.motors)]
steppers.bcm2835_init()
for motor in self.motors:
motor.begin()
motor.toff(5)
# ideally should be 0
# on working equipment it is always 2
assert motor.test_connection() == 2
motor.rms_current(600)
motor.microsteps(16)
motor.en_pwm_mode(True)
steppers.bcm2835_close()
def build(self, do_program=True, verbose=True):
'''builds the FPGA code using nMigen, Yosys, Nextpnr and icepack
do_program -- flashes the FPGA chip using fomu-flash,
resets aftwards
verbose -- prints output of Yosys, Nextpnr and icepack
'''
if upython:
print("Micropython cannot update binary, using stored one")
else:
import hexastorm.core as core
self.platform = Firestarter()
self.platform.laser_var = self.laser_params
self.platform.build(core.Dispatcher(self.platform),
do_program=do_program,
verbose=verbose)
if do_program:
self.reset()
def reset(self):
'restart the FPGA by flipping the reset pin'
if upython:
import machine
reset_pin = machine.Pin(self.platform.reset_pin)
else:
from gpiozero import LED
reset_pin = LED(self.platform.reset_pin)
reset_pin.off()
sleep(1)
reset_pin.on()
sleep(1)
# a blank needs to be send, Statictest succeeds but
# testlaser fails in test_electrical.py
# on HX4K this was not needed
# is required for the UP5K
self.spi_exchange_data([0]*(WORD_BYTES+COMMAND_BYTES))
def get_state(self, data=None):
'''retrieves the state of the FPGA as dictionary
data: string to decode to state, if None data is retrieved from FPGA
dictionary with the following keys
parsing: True if commands are executed
mem_full: True if memory is full
error: True if an error state is reached by any of
the submodules
x, y, z: state of motor endswitches
photodiode_trigger: True if photodiode is triggered during last
rotation of prism
synchronized: True if laserhead is synchronized by photodiode
'''
if data is None:
command = [COMMANDS.READ] + WORD_BYTES*[0]
data = (yield from self.send_command(command))
dct = {}
# 9 bytes are returned
# the state is decoded from byte 7 and 8, i.e. -2 and -1
bits = "{:08b}".format(data[-1])
dct['parsing'] = int(bits[STATE.PARSING])
dct['error'] = int(bits[STATE.ERROR])
dct['mem_full'] = int(bits[STATE.FULL])
bits = "{:08b}".format(data[-2])
mapping = list(self.platform.stepspermm.keys())
for i in range(self.platform.motors):
dct[mapping[i]] = int(bits[i])
dct['photodiode_trigger'] = int(bits[self.platform.motors])
dct['synchronized'] = int(bits[self.platform.motors+1])
return dct
@property
def position(self):
'''retrieves position from FPGA and updates internal position
position is stored on the FPGA in steps
position is stored on object in mm
return positions as np.array in mm
order is [x, y, z]
'''
command = [COMMANDS.POSITION] + WORD_BYTES*[0]
for i in range(self.platform.motors):
read_data = (yield from self.send_command(command))
self._position[i] = unpack('!q', read_data[1:])[0]
# step --> mm
self._position = (self._position /
np.array(list(self.platform.stepspermm.values())))
return self._position
@property
def enable_steppers(self):
'''returns 1 if steppers are enabled, 0 otherwise
The enable pin for the stepper drivers is not routed via FPGA.
The enable pin is low if enabled.
Enabled stepper motor do not move if the FPGA is
not parsing instructions from FIFO.
'''
return not self.enable.value
@enable_steppers.setter
def enable_steppers(self, val):
'''set enable pin stepper motor drivers and parsing FIFO buffer by FPGA
val -- boolean, True enables steppers
'''
assert type(val) == bool
if val:
self.enable.off()
self.spi_exchange_data([COMMANDS.START]+WORD_BYTES*[0])
else:
self.enable.on()
self.spi_exchange_data([COMMANDS.STOP]+WORD_BYTES*[0])
@property
def laser_current(self):
'''return laser current per channel as integer
both channels have the same current
integer ranges from 0 to 255 where
0 no current and 255 full driver current
'''
if upython:
data = bytearray(1)
self.bus.recv(data)
else:
data = self.bus.read_byte_data(self.platform.ic_address,
0)
return data
@laser_current.setter
def laser_current(self, val):
'''sets maximum laser current of laser driver per channel
This does not turn on or off the laser. Laser is set
to this current if pulsed. Laser current is set by enabling
one or two channels. Second by setting a value between
0-255 at the laser driver chip for the laser current. The laser
needs a minimum current.
'''
if val < 0 or val > 150:
# 255 kills laser at single channel
raise Exception('Invalid or too high laser current')
if upython:
self.bus.mem_write(val, self.platform.ic_address)
else:
self.bus.write_byte_data(self.platform.ic_address, 0, val)
def set_parsing(self, value):
'''enables or disables parsing of FIFO by FPGA
val -- True FPGA parses FIFO
False FPGA does not parse FIFO
'''
assert type(value) == bool
if value:
command = [COMMANDS.START]
else:
command = [COMMANDS.STOP]
command += WORD_BYTES*[0]
return (yield from self.send_command(command))
def home_axes(self, axes, speed=None, displacement=-200):
'''home given axes, i.e. [1,0,1] homes x, z and not y
axes -- list with axes to home
speed -- speed in mm/s used to home
displacement -- displacement used to touch home switch
'''
assert len(axes) == self.platform.motors
dist = np.array(axes)*np.array([displacement]*self.platform.motors)
yield from self.gotopoint(position=dist.tolist(),
speed=speed, absolute=False)
# TODO: this is strange, should it be here
# on the board steps and count is stored
# you could move this to spline_coefficients
# the flow over method of a certain bit comes from beagleg
def steps_to_count(self, steps):
'''compute count for a given number of steps
steps -- motor moves in small steps
Shift is needed as two ticks per step are required
You need to count slightly over the threshold. That is why
+1 is added.
'''
bitshift = bit_shift(self.platform)
count = (steps << (1+bitshift))+(1 << (bitshift-1))
return count
def gotopoint(self, position, speed=None, absolute=True):
'''move machine to position or with displacement at constant speed
Axes are moved independently to simplify the calculation.
The move is carried out as a first order spline, i.e. only velocity.
position -- list with position or displacement in mm for each motor
speed -- list with speed in mm/s, if None default speeds used
absolute -- True if position, False if displacement
'''
assert len(position) == self.platform.motors
if speed is not None:
assert len(speed) == self.platform.motors
else:
speed = [10]*self.platform.motors
# conversions to steps / count give rounding errors
# minimized by setting speed to integer
speed = np.absolute(np.array(speed))
displacement = np.array(position)
if absolute:
# TODO: position machine should be in line with self._position
# which to pick?
displacement -= self._position
homeswitches_hit = [0]*len(position)
for idx, disp in enumerate(displacement):
if disp == 0:
# no displacement, go to next axis
continue
# Time needed for move
# unit oscillator ticks (times motor position is updated)
time = abs(disp/speed[idx])
ticks_total = (time*MOTORFREQ).round().astype(int)
# mm -> steps
steps_per_mm = list(self.platform.stepspermm.values())[idx]
speed_steps = int(round(speed[idx] * steps_per_mm*np.sign(disp)))
speed_cnts = self.steps_to_count(speed_steps)/MOTORFREQ
velocity = np.zeros_like(speed).astype('int64')
velocity[idx] = speed_cnts
if self.test:
(yield from self.set_parsing(True))
else:
self.set_parsing(True)
while ticks_total > 0:
ticks_move = \
MOVE_TICKS if ticks_total >= MOVE_TICKS else ticks_total
# execute move and retrieve if switch is hit
switches_hit = (yield from self.spline_move(int(ticks_move),
velocity.tolist()))
ticks_total -= ticks_move
# move is aborted if home switch is hit and
# velocity is negative
cond = (switches_hit[idx] == 1) & (np.sign(disp) < 0)
if cond:
break
# update internally stored position
self._position += displacement
# set position to zero if home switch hit
self._position[homeswitches_hit == 1] = 0
def send_command(self, command, blocking=False):
'''writes command to spi port
blocking -- try again if memory is full
returns bytearray with length equal to data sent
'''
def send_command(command):
assert len(command) == WORD_BYTES+COMMAND_BYTES
if self.test:
data = (yield from self.spi_exchange_data(command))
else:
data = (self.spi_exchange_data(command))
return data
if blocking:
trials = 0
while True:
trials += 1
data = (yield from send_command(command))
state = (yield from self.get_state(data))
if state['error']:
raise Exception("Error detected on FPGA")
if not state['mem_full']:
break
if trials > self.maxtrials:
raise Memfull(f"Too many trials {trials} needed")
else:
data = (yield from send_command(command))
return data
def enable_comp(self, laser0=False, laser1=False,
polygon=False, synchronize=False):
'''enable components
FPGA does need to be parsing FIFO
These instructions are executed directly.
laser0 -- True enables laser channel 0
laser1 -- True enables laser channel 1
polygon -- False enables polygon motor
'''
laser0, laser1, polygon = (int(bool(laser0)),
int(bool(laser1)),
int(bool(polygon)))
synchronize = int(bool(synchronize))
data = ([COMMANDS.WRITE] + [0]*(WORD_BYTES-2) +
[int(f'{synchronize}{polygon}{laser1}{laser0}', 2)]
+ [INSTRUCTIONS.WRITEPIN])
yield from self.send_command(data, blocking=True)
def spline_move(self, ticks, coefficients):
'''write spline move instruction with ticks and coefficients to FIFO
If you have 2 motors and execute a second order spline
You send 4 coefficients.
If the controller supports a third order spline,
remaining coefficients are padded as zero.
User needs to submit all coefficients up to highest order used.
ticks -- number of ticks in move, integer
coefficients -- coefficients for spline move per axis, list
returns array with zero if home switch is hit
'''
platform = self.platform
# maximum allowable ticks is move ticks,
# otherwise counters overflow in FPGA
assert ticks <= MOVE_TICKS
assert len(coefficients) % platform.motors == 0
write_byte = COMMANDS.WRITE.to_bytes(1, 'big')
move_byte = INSTRUCTIONS.MOVE.to_bytes(1, 'big')
commands = [write_byte +
ticks.to_bytes(7, 'big') + move_byte]
# check max order given by caller of function
max_coeff_order = (len(coefficients)//platform.motors)
# prepare commands
for motor in range(platform.motors):
for degree in range(platform.poldegree):
# set to zero if coeff not provided by caller
if degree > max_coeff_order-1:
coeff = 0
else:
idx = degree+motor*max_coeff_order
coeff = coefficients[idx]
data = coeff.to_bytes(8, 'big', signed=True)
commands += [write_byte + data]
# send commands to FPGA
for command in commands:
data_out = (yield from self.send_command(command,
blocking=True))
state = (yield from self.get_state(data_out))
axes_names = list(platform.stepspermm.keys())
return np.array([state[key] for key in axes_names])
def spi_exchange_data(self, data):
'''writes data to peripheral
data -- command followed with word
list of multiple bytes
returns bytearray with length equal to data sent
'''
assert len(data) == (COMMAND_BYTES + WORD_BYTES)
self.chip_select.off()
# spidev changes values passed to it
if not upython:
from copy import deepcopy
datachanged = deepcopy(data)
response = bytearray(self.spi.xfer2(datachanged))
else:
response = bytearray(data)
self.spi.write_readinto(data, response)
self.chip_select.on()
return response
def writeline(self, bitlst, stepsperline=1, direction=0):
'''write bits to FIFO
bit list bits which are written to substrate
at the moment laser can only be on of off
if bitlst is empty stop command is sent
stepsperline stepsperline, should be greater than 0
if you don't want to move simply disable motor
direction motor direction of scanning axis
'''
bytelst = self.bittobytelist(bitlst, stepsperline, direction)
write_byte = COMMANDS.WRITE.to_bytes(1, 'big')
for i in range(0, len(bytelst), 8):
lst = bytelst[i:i+8]
lst.reverse()
data = write_byte + bytes(lst)
(yield from self.send_command(data, blocking=True))
def bittobytelist(self, bitlst, stepsperline=1,
direction=0, bitorder='little'):
'''converts bitlst to bytelst
bit list bits which are written to substrate
at the moment laser can only be on of off
if bitlst is empty stop command is sent
stepsperline stepsperline, should be greater than 0
if you don't want to move simply disable motor
direction motor direction of scanning axis
'''
# the halfperiod is sent over
# this is the amount of ticks in half a cycle of
# the motor
# watch out for python "banker's rounding"
# sometimes target might not be equal to steps
bits = self.laser_params['BITSINSCANLINE']
halfperiod = int((bits-1) // (stepsperline*2))
if (halfperiod < 1):
raise Exception("Steps per line cannot be achieved")
# TODO: is this still an issue?
# you could check as follows
# steps = self.laser_params['TICKSINFACET']/(halfperiod*2)
# print(f"{steps} is actual steps per line")
direction = [int(bool(direction))]
def remainder(bytelst):
rem = (len(bytelst) % WORD_BYTES)
if rem > 0:
res = WORD_BYTES - rem
else:
res = 0
return res
if len(bitlst) == 0:
bytelst = [INSTRUCTIONS.LASTSCANLINE]
bytelst += remainder(bytelst)*[0]
else:
assert len(bitlst) == self.laser_params['BITSINSCANLINE']
assert max(bitlst) <= 1
assert min(bitlst) >= 0
bytelst = [INSTRUCTIONS.SCANLINE]
halfperiodbits = [int(i) for i in bin(halfperiod)[2:]]
halfperiodbits.reverse()
assert len(halfperiodbits) < 56
bytelst += np.packbits(direction+halfperiodbits,
bitorder=bitorder).tolist()
bytelst += remainder(bytelst)*[0]
bytelst += np.packbits(bitlst, bitorder=bitorder).tolist()
bytelst += remainder(bytelst)*[0]
return bytelst
