add real time plotting functionality

src/flow_meter.py

@@ -23,12 +23,12 @@ def __init__(self, port='/dev/ttyUSB0', baudrate=460800, slave_address=2):
         self.device = Sfc5xxxShdlcDevice(ShdlcConnection(self.port), slave_address=slave_address)
         self.device.activate_calibration(3) # specify calibration file index in list; default now on Helium (3)
         # set units
-        self.unit = Sfc5xxxMediumUnit(
+        self._unit = Sfc5xxxMediumUnit(
             Sfc5xxxUnitPrefix.ONE,
             Sfc5xxxUnit.STANDARD_LITER,
             Sfc5xxxUnitTimeBase.MINUTE
         )
-        self.device.set_user_defined_medium_unit(self.unit)
+        self.device.set_user_defined_medium_unit(self._unit)
 
 
     def set_baudrate(self, baudrate):
@@ -54,7 +54,7 @@ def get_reading(self, duration):
         # dump what's already inside the buffer. this is only useful for low overhead
         #buffer = self.device.read_measured_value_buffer(Sfc5xxxScaling.USER_DEFINED)
         while len(reading) <= duration * 1000: # flow meter reads at 1kHz
-            buffer = self.device.read_measured_value_buffer(Sfc5xxxScaling.USER_DEFINED)
+            buffer = self.device.read_measured_value_buffer(Sfc5xxxScaling.USER_DEFINED, max_reads=2)
             #print(buffer.sampling_time) # the only "time" returned from read buffer command
             reading.extend(buffer.values)
         return reading

src/kernel.py

@@ -1,4 +1,5 @@
 import numpy as np
+import matplotlib.pyplot as plt
 import RPi.GPIO as GPIO
 import time
 #from wavegen_control import wavegen_control
@@ -37,7 +38,7 @@ def __init__(self, gpio_channel) -> None:
 
    # def burst_mode(self, ncycles):
        # self.wavegen.burst(enable=True, ncycles=ncycles, phase=0)
-        
+
 
     def acquire(self, duration, acquisition_limit=100):
         """
@@ -51,24 +52,41 @@ def acquire(self, duration, acquisition_limit=100):
         acquisition_limit : Maximum number of acquisition the command can perform.
         """
         shot_counts = 0
+<<<<<<< HEAD
+        plt.ion()
+        fig, ax = plt.subplots()
+        line, = ax.plot(np.zeros(int(duration*1000)))
+        ax.set_title('real time flow rate')
+        ax.set_ylabel('flow rate ('+self.flow_meter._unit.__str__()+')')
+        t = time.time()
+=======
+        fig, ax = plt.subplots()
+        line, = ax.plot(np.zeros(100))
+>>>>>>> b958ecfa45898f915dbcd9bcc629f6a464d36aab
         try:
             while shot_counts <= acquisition_limit:
                 print('waiting for signals...')
                 GPIO.wait_for_edge(self.gpio_channel, GPIO.RISING) # stop the code until receiving a trigger
                 #time.sleep(.1)
-                t = time.time()
-                #readings = np.array(self.flow_meter.get_reading(duration))
-                readings = np.array(self.flow_meter.get_reading_single_cycle(duration))
+                readings = np.array(self.flow_meter.get_reading(duration))
+                #readings = np.array(self.flow_meter.get_reading_single_cycle(duration))
                 #readings = np.array(self.flow_meter.get_single_buffer())
-                np.savetxt(f'/home/pi/flow_meter/data/output_single_cycle_{shot_counts}.csv', readings)
+                np.savetxt(f'/home/pi/flow_meter/data/0208/output_{shot_counts}.csv', readings)
                 print('shot count {}'.format(shot_counts))
                 print(f'shot interval {time.time()-t}')
+<<<<<<< HEAD
+                t = time.time()
+                line.set_ydata(readings[:int(duration*1000)])
+                ax.set_ylim(0,max(readings)*1.2)
+=======
+                line.set_ydata(readings)
+>>>>>>> b958ecfa45898f915dbcd9bcc629f6a464d36aab
+                fig.canvas.draw()
+                fig.canvas.flush_events()
                 shot_counts += 1
+            print('Maximum number of shot records reached!')
         except KeyboardInterrupt:
-            GPIO.cleanup()
             print('exit on ctrl-C keyboard interrupt')
-        except:
-            GPIO.cleanup()
-            print('an error occured')
-        print('Maximum number of shot records reached!')
-        GPIO.cleanup()
+        except Exception as error:
+            print('an error occured:\n', error)
+

src/plot.py

@@ -1,5 +1,8 @@
 import numpy as np
 import matplotlib.pyplot as plt
+import matplotlib
+
+#matplotlib.rcParams['backend'] = 'agg'
 
 data = np.loadtxt('/home/pi/flow_meter/data/output_0.csv')
 plt.plot(data)