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import serial
import os
from time import localtime, strftime, sleep
import credentials
MAP_FILE = credentials.MAP_FILE
#LOG_FILE = '../log/sbhserr.log'
LOG_FILE = credentials.LOG_FILE
OUTGOING_MACHINE_ID = 252
INCOMING_FAN = 253
INCOMING_HEAT = 254
OUTGOING_TEMP = 255
MAX_HEAT = 100
MAX_FAN = 100
class Sbhs:
""" This is the Single Board Heater System class """
def __init__(self):
""" status of the board
0 = not connected
1 = connected
"""
self.machine_id = 26
self.device_num = 26
self.boardcon = False
self.status = 0
def connect(self, machine_id):
""" Open a serial connection via USB to the SBHS using the machine id """
# check for valid machine id number
try:
self.machine_id = int(machine_id)
except:
#with open('error.txt', 'w') as errrr:
# errrr.write('Invalid machine id specified % d' % self.machine_id)
return False
# get the usb device file from the machine map file
try:
map_file = open(MAP_FILE, 'r')
usb_device_file = False
for mapping_str in map_file.readlines():
mapping = mapping_str.split('=')
self.log('mapping: ' + mapping[1], 'ERROR') #srikant
# if mapping for the machine id found set the usb device file and break out of loop
if mapping[0] == str(self.machine_id):
usb_device_file = mapping[1].strip()
#self.log('usb_device_file: ' + usb_device_file, 'ERROR') #srikant
break
# reached end of file and check if machine id entry is present in the machine map file
map_file.close()
if not usb_device_file:
print 'Error: cannot locate the USB device in the map table for machine id %d' % self.machine_id
self.log('cannot locate the USB device in the map table for machine id %d' % self.machine_id, 'ERROR')
return False
except:
# map_file.close()
print 'Error: cannot get the USB device path for the machine id %d' % self.machine_id
self.log('cannot get the USB device path for the machine id %d' % self.machine_id, 'ERROR')
return False
# check if SBHS device is connected
if not os.path.exists(usb_device_file):
print 'SBHS device file ' + usb_device_file + ' does not exists'
self.log('SBHS device file ' + usb_device_file + ' does not exists', 'ERROR')
return False
try:
self.boardcon = serial.Serial(port=usb_device_file, baudrate=9600, bytesize=8, parity='N', stopbits=1, timeout=2) #orignal stopbits = 1
self.status = 1
return True
except serial.serialutil.SerialException:
print 'Error: cannot connect to machine id %d' % self.machine_id
self.log('cannot connect to machine id %d' % self.machine_id, 'ERROR')
self.machine_id = -1
self.device_num = -1
self.boardcon = False
self.status = 0
def connect_device(self, device_num):
""" Open a serial connection via USB to the SBHS using USB Device Number"""
# check for valid device number
try:
self.device_num = int(device_num)
except:
print 'Invalid device number specified'
return False
usb_device_file = '/dev/ttyUSB%d' % self.device_num
# check if SBHS device is connected
if not os.path.exists(usb_device_file):
print 'SBHS device file ' + usb_device_file + ' does not exists'
self.log('SBHS device file ' + usb_device_file + ' does not exists', 'ERROR')
return False
try:
self.boardcon = serial.Serial(port=usb_device_file, baudrate=9600, bytesize=8, parity='N', stopbits=1, timeout=2) # org stopbits = 1
self.machine_id = self.getMachineId()
if self.machine_id != -1:
return True
else:
print "Machine %s not responding. Check SBHS device!!" % usb_device_file
except:
print 'Error: cannot connect to device %s' % usb_device_file
self.log('cannot connect to device %s' % usb_device_file, 'ERROR')
return False
def setHeat(self, val):
""" Sets the heat, checks if value is valid i.e. within range.
Input: self object, val
Output: Error message if heat cannot be set.
"""
if val > MAX_HEAT or val < 0:
print 'Error: heat value cannot be more than %d' % MAX_HEAT
return False
try:
self._write(chr(INCOMING_HEAT))
sleep(0.5)
self._write(chr(val))
return True
except:
print 'Error: cannot set heat for machine id %d' % self.machine_id
self.log('cannot set heat for machine id %d' % self.machine_id, 'ERROR')
return False
def setFan(self, val):
""" Sets the fan speed, checks if value is valid i.e. within range.
Input: self object, val
Output: Error message if fan cannot be set.
"""
if val > MAX_FAN or val < 0:
print 'Error: fan value cannot be more than %d' % MAX_FAN
return False
try:
self._write(chr(INCOMING_FAN))
sleep(0.5)
self._write(chr(val))
return True
except:
print 'Error: cannot set fan for machine id %d' % self.machine_id
self.log('cannot set fan for machine id %d' % self.machine_id, 'ERROR')
return False
def getTemp(self):
""" Gets the temperature from the machine.
"""
try:
self.boardcon.flushInput()
self._write(chr(OUTGOING_TEMP))
temp = ord(self._read(1)) + (0.1 * ord(self._read(1)))
return temp
except:
print 'Error: cannot read temperature from machine id %d' % self.machine_id
self.log('cannot read temperature from machine id %d' % self.machine_id, 'ERROR')
return 0.0
def getMachineId(self):
""" Gets machine id from the device """
try:
self.boardcon.flushInput()
self._write(chr(OUTGOING_MACHINE_ID))
sleep(0.5)
machine_id = ord(self._read(1))
return machine_id
except:
print 'Error: cannot read machine id from %s' % self.boardcon.port
self.log('cannot read machine id from %s' % self.boardcon.port, 'ERROR')
return -1
def disconnect(self):
""" Reset the board fan and heat values and close the USB connection """
try:
self.boardcon.close()
self.boardcon = False
self.status = 0
return True
except:
print 'Error: cannot close connection to the machine'
self.log('cannot close connection to the machine', 'ERROR')
return False
def reset_board(self):
return self.setHeat(0) and self.setFan(100)
def _read(self, size):
try:
data = self.boardcon.read(size)
return data
except:
print 'Error: cannot read from machine id %d' % self.machine_id
self.log('cannot read from machine id %d' % self.machine_id, 'ERROR')
raise Exception
def _write(self, data):
try:
self.boardcon.write(data)
return True
except:
print 'Error: cannot write to machine id %d' % self.machine_id
self.log('cannot write to machine id %d' % self.machine_id, 'ERROR')
raise Exception
def log(self, msg, level):
try:
errfile = open(LOG_FILE, 'a') # open error log file in append mode
if not errfile:
return
log_msg = '%s %s %s\n' %(level, strftime('%d:%m:%Y %H:%M:%S', localtime()), msg)
errfile.write(log_msg)
errfile.close()
return
except:
return
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