move to a more standard python packaging structure

src/damaris/tools/eurotherm.py

@@ -0,0 +1,120 @@
+import serial
+import re
+import operator
+from functools import reduce
+
+
+DEBUG=False
+
+reply_pattern = re.compile(r"\x02..(.*)\x03.", re.DOTALL)
+# example answer '\x02PV279.8\x03/'
+# [EOT] = \x04
+# [STX] = \x02
+# [ENQ] = \x05
+# [ETX] = \x03
+# [ACK] = \x06
+# BCC = checksum
+
+standard_device='0011'
+EOT = '\x04'
+STX = '\x02'
+ENQ = '\x05'
+ETX = '\x03'
+ACK = '\x06'
+NAK = '\x15'
+
+
+"""
+Paramter read example:
+
+Master: [EOT]0011PV[ENQ]
+Instrument:				[STX]PV16.4[ETX]{BCC}
+
+Writing data:
+
+Master: [EOT] {GID}{GID}{UID}{UID}[STX]{CHAN}(c1)(c2)<DATA>[ETX](BCC)
+
+"""
+
+def checksum(message):
+	bcc = (reduce(operator.xor, list(map(ord,message))))
+	return chr(bcc)
+
+class Eurotherm(object):
+	def __init__(self, serial_device, baudrate = 19200):
+		self.device = standard_device
+		# timeout: 110 ms to get all answers.
+		self.s = serial.Serial(serial_device,
+					baudrate = baudrate,
+					bytesize=7,
+					parity='E',
+					stopbits=1,
+					timeout=0.11)
+		self._expect_len = 50
+
+	def send_read_param(self, param):
+		self.s.write(EOT + self.device + param + ENQ)
+
+	def read_param(self, param):
+		self.s.flushInput()
+		self.send_read_param(param)
+		answer = self.s.read(self._expect_len)
+		m = reply_pattern.search(answer)
+		if m is None:
+			# Reading _expect_len bytes was not enough...
+			answer += self.s.read(200)
+			m = reply_pattern.search(answer)
+		if m is not None:
+			self._expect_len = len(answer)
+			return m.group(1)
+		else:
+			print("received:", repr(answer))
+			return None
+
+	def write_param(self, mnemonic, data):
+		if len(mnemonic) > 2:
+			raise ValueError
+		bcc = checksum(mnemonic + data + ETX)
+		mes = EOT+self.device+STX+mnemonic+data+ETX+bcc
+		if DEBUG:
+			for i in  mes:
+				print(i,hex(ord(i)))
+		self.s.flushInput()
+		self.s.write(mes)
+		answer = self.s.read(1)
+		# print "received:", repr(answer)
+		if answer == "":
+			# raise IOError("No answer from device")
+			return None
+		return answer[-1] == ACK
+
+	def get_current_temperature(self):
+		temp = self.read_param('PV')
+		if temp is None:
+			temp = "0"
+		return temp
+
+	def set_temperature(self, temperature):
+		return self.write_param('SL', str(temperature))
+
+	def get_setpoint_temperature(self):
+		return self.read_param('SL')
+
+if __name__ == '__main__':
+	import time
+	delta=5
+	date = time.strftime('%Y-%m-%d')
+	f = open('templog_%s'%date,'w')
+	f.write('# Start time: %s\n#delta t : %.1f s\n'%(time.asctime(), delta))
+	et = Eurotherm("/dev/ttyUSB0")
+	while True:
+		for i in range(120):
+			time.sleep(delta)
+			#t = time.strftime()
+			T = et.get_current_temperature()
+				
+			l = '%f %s\n'%(time.time(),T)
+			print(time.asctime(), T)
+			f.write(l)
+			f.flush()
+		f.write('# MARK -- %s --\n'%(time.asctime()))