MIN_GAIN, MAX_GAIN = 0.5, 1.1
DECREMENT_STEP = 0.02
INCREMENT_FACTOR = 0.5
SCAN_RANGE_FACTOR = 6
MAX_RANGE_STEP = 200

new_gain, new_voltage = None, None
desired_loss=get_blm_saturation(blms[i])

current_voltage = get_blm_ws_gain(blms[i]) #read_ws_gain (blms[i], wire)
#current_loss = float(get_blm_loss(blms[i]))
current_loss = 1700
current_gain = get_gain_from_voltage(current_voltage)
if False: #current_loss > desired_loss:
   #Gain must decrease. Fixed steps down
   if current_voltage > MIN_GAIN:
       new_gain = max(current_voltage - DECREMENT_STEP, MIN_GAIN)
else:
   #Gain must be increasede. Step proportional to the difference
   dg =  current_gain * (desired_loss/ current_loss -1)
   new_gain = current_gain + dg * INCREMENT_FACTOR
   new_voltage = get_voltage_from_gain(new_gain)
   new_voltage = max(min(new_voltage, MAX_GAIN),MIN_GAIN)
   print "dg=", dg, " ng=", new_gain   
if (new_voltage is not None) and (new_voltage != current_voltage):
   logstr= "Adapting " , blms[i], " - ", wire, "gain: ", new_voltage
   print logstr
   log(logstr)
   write_ws_gain(blms[i], wire, new_voltage)