initial commit

.gitignore

+*~
+*.pyc
+__pycache__

u3_module.py

+#!/usr/bin/python3
+
+from joule.utils.time import now as time_now
+from joule.client import ReaderModule
+import asyncio
+import numpy as np
+
+import u3
+import time
+import traceback
+import sys
+
+class U3Reader(ReaderModule):
+    "Read data from U3 LabJack"
+
+    def __init__(self):
+        super(U3Reader, self).__init__("LabJack U3 Reader")
+        self.description = "collect data from a U3 device"
+        self.help = "collects 3 channels @ 5KHz"
+
+        self.data_ts_inc = 1e6 / 5000.0 # 5KHz sampling
+        self.stop_requested = False
+
+        # configure U3
+        self.device = u3.U3()
+        self.device.configU3()
+        self.device.streamConfig(NumChannels=3,
+                                 PChannels=[0,1,2],
+                                 NChannels=[31,31,31],
+                                 ScanFrequency=5000,
+                                 SamplesPerPacket=25)
+
+
+        #secs_per_req = (25*self.device.packetsPerRequest/3.0)/5000.0
+        #self.sleep_time = 0.75*secs.per_req
+        
+    def custom_args(self, parser):
+        pass
+
+    async def run(self, parsed_args, output):
+        # set up timestamps
+        data_ts = int(time.time()*1e6)
+        try:
+            self.device.streamStart()
+            while(not self.stop_requested):
+                r = next(self.device.streamData())
+                if(r['errors']!=0 or r['missed']!=0):
+                    sys.stderr.write("errors: %d, missed: %d\n" % (
+                        r['errors'],r['missed']))
+                    
+                (data_ts, block) = self.build_block(r,data_ts)
+                await output.write(block)
+        except:
+            print("".join(i for i in traceback.format_exc()))
+        finally:
+            self.device.streamStop()
+            self.device.close()
+
+    def build_block(self,r,data_ts):
+        rows = len(r['AIN0'])
+        block = np.empty((rows,4))
+        top_ts = data_ts + rows * self.data_ts_inc
+        ts = np.array(np.linspace(data_ts, top_ts,
+                                  rows, endpoint=False), dtype=np.uint64)
+        block = np.vstack((ts,r['AIN0'],r['AIN1'],r['AIN2'])).T
+        return (top_ts, block)
+                    
+            
+if __name__ == "__main__":
+    r = U3Reader()
+    r.start()

u3_reader.py

+#!/usr/bin/python3
+
+import u3
+import pdb
+import traceback
+
+def main():
+
+    d = u3.U3()
+    d.configU3()
+    d.streamConfig(NumChannels=3, PChannels=[0,1,2], NChannels=[31,31,31],
+                   ScanFrequency=5000)
+
+    try:
+        d.streamStart()
+        for r in d.streamData():
+            for x in r["AIN0"]:
+                print(x)
+    except:
+        print("".join(i for i in traceback.format_exc()))
+    finally:
+        d.streamStop()
+        d.close()
+
+if __name__=="__main__":
+    main()