def load_devices(self, sources):
devices = []
handler = ctypes.c_int16()
# Get list if ports
device_ports = []
for source in sources:
device_ports.append(source["port"])
device_ports.sort()
for device in sources:
# Using ctypes Handler like PicoSDK Example
response = usbtc08.usb_tc08_open_unit()
if response == 0:
# Returns zero when no unopened units left
break
if response not in device_ports:
check_api_response(usbtc08.usb_tc08_close_unit(handler))
break
else:
# Check if opened sucessfully, and assign handler
handler = check_api_response(response)
# Set each device to reject either 50 or 60 Hz interference
# 1: Reject 60Hz, 2: Reject 50Hz
check_api_response(usbtc08.usb_tc08_set_mains(handler, 0))
devices.append(handler)
return devices
assert_pico2000_ok(status["set_mains"])
# set up channel
# therocouples types and int8 equivalent
# B=66 , E=69 , J=74 , K=75 , N=78 , R=82 , S=83 , T=84 , ' '=32 , X=88
typeK = ctypes.c_int8(75)
status["set_channel"] = tc08.usb_tc08_set_channel(chandle, 1, typeK)
assert_pico2000_ok(status["set_channel"])
# get minimum sampling interval in ms
status["get_minimum_interval_ms"] = tc08.usb_tc08_get_minimum_interval_ms(
chandle)
assert_pico2000_ok(status["get_minimum_interval_ms"])
# get single temperature reading
temp = (ctypes.c_float * 9)()
overflow = ctypes.c_int16(0)
units = tc08.USBTC08_UNITS["USBTC08_UNITS_CENTIGRADE"]
status["get_single"] = tc08.usb_tc08_get_single(chandle, ctypes.byref(temp),
ctypes.byref(overflow), units)
assert_pico2000_ok(status["get_single"])
# print data
print("Cold Junction ", temp[0], " Channel 1 ", temp[1])
# close unit
status["close_unit"] = tc08.usb_tc08_close_unit(chandle)
assert_pico2000_ok(status["close_unit"])
# display status returns
print(status)
def cleanup(self):
# Closes all devices
for handler in self.devices:
check_api_response(usbtc08.usb_tc08_close_unit(handler))
self.logger.info("Closed all devices.")
def monitor_temperatures(cadence):
""" Monitor temperatures thread
:param cadence: Time between measurements """
global stop_acquisition
# Initialise picologger device
import ctypes
from picosdk.usbtc08 import usbtc08 as tc08
from picosdk.functions import assert_pico2000_ok
# Create chandle and status ready for use
chandle = ctypes.c_int16()
status = {}
# open unit
chandle = None
try:
ret = tc08.usb_tc08_open_unit()
assert_pico2000_ok(ret)
chandle = ret
except:
logging.error(
"Could not initialised picologger. Not getting temperatures")
return
try:
# Set mains rejection to 50 Hz
status["set_mains"] = tc08.usb_tc08_set_mains(chandle, 0)
assert_pico2000_ok(status["set_mains"])
# Set up channels (all type K, cold junction needs to be C)
typeC = ctypes.c_int8(67)
assert_pico2000_ok(tc08.usb_tc08_set_channel(chandle, 0, typeC))
typeK = ctypes.c_int8(75)
for channel in range(1, 9):
assert_pico2000_ok(
tc08.usb_tc08_set_channel(chandle, channel, typeK))
except:
logging.error(
"Error while setting up picologger. Not getting temperatures")
tc08.usb_tc08_close_unit(chandle)
return
temp = (ctypes.c_float * 9)()
overflow = ctypes.c_int16(0)
units = tc08.USBTC08_UNITS["USBTC08_UNITS_CENTIGRADE"]
# Read temperatures till told to stop
while not stop_acquisition:
# Read temperatures
try:
assert_pico2000_ok(
tc08.usb_tc08_get_single(chandle, ctypes.byref(temp),
ctypes.byref(overflow), units))
except:
logging.error(
"Error while getting temperatures, not reading temperatures anymore"
)
tc08.usb_tc08_close_unit(chandle)
return
# Get timestamp
timestamp = time.time()
# Add RMS to file
add_temperatures_to_file(np.array(temp), timestamp)
# Sleep for required time
time.sleep(cadence)