import time
from .psw_gw_instek import GWInstekPSW
from .tpg262_gnome232 import TPG262GNOME232
def write2file(fname, value):
with open(fname, 'w') as f:
f.write(str(value))
def fill_chamber(target_pressure, eps=0.1, start_v=10,
interval=0.5, proportional_const=1e-1, derivative_const=1e-1,
max_time=60, fail_pressure=200,
psw_address='192.168.2.75', gauge_address='192.168.2.246',
verbose=False):
psw = GWInstekPSW(psw_address)
gauge = TPG262GNOME232(gauge_address)
v = start_v
psw.set_voltage(v)
psw.set_output(True)
last_p = p = 0
start_t = time.time()
while True:
#for x in range(10):
last_p = p
p = gauge.get_pressure(1) * 1e3 # to mPa
write2file('/dev/shm/pressure_chamber_mPa', p)
if p > fail_pressure:
psv.set_output(False)
raise RuntimeError('pressure {} over limit {}'.format(p, fail_pressure))
elapsed = time.time() - start_t
if elapsed > max_time:
raise RuntimeError('did not converge, maintaining pressure {}'.format(p))
err = target_pressure - p
change = p - last_p
if abs(err) < eps and abs(change)/interval < eps:
if verbose:
print('reached pressure {} with error {} and change {} in {} seconds '.format(p, err, change, elapsed))
break
v += proportional_const * err - derivative_const * change / interval
psw.set_voltage(v)
if verbose:
print('pressure {}, setting voltage {}'.format(p, v))
time.sleep(interval)
def close_valve(psw_address='192.168.2.75'):
psw = GWInstekPSW(psw_address)
psw.set_output(False)
