def send_msg(s, msg, timeout, retries, ack):
buff = ""
for i in range(retries):
s.write(msg)
Logger.log_write("Sending out '{0}' to arduino, retry {1}".format(msg, i))
s.flush()
start_time = time.time()
end_time = time.time()
while end_time - start_time < timeout:
r = s.readline()
Logger.log_write(
"Got back '{0}' from arduino, time left till timeout: {1:f}s".format(
r, timeout - time.time() + start_time
)
)
buff += r
if r:
print 'Got msg "{0}" from upstream'.format(r)
if "FAIL" in r:
print "Found failure condition in response, resending"
Logger.log_write("Matched failure condition, resending")
break
if ack in buff:
# print 'Found ACK condition in response, accepting'
Logger.log_write("Found ACK condition, accepting")
break
end_time = time.time()
if ack in buff:
return True
else:
Logger.log_write("no msg was ack'd, giving up")
return False
def msg_sender(pipe, avail, port, rate, timeout, retries):
# establish serial connection
try:
s = serial.Serial(port, rate, timeout=timeout)
print "Established connection, commencing initial wait for handshakes(5s)"
time.sleep(5)
print "Connection should be up now, testing with ready"
if not ready_waiter(s, avail, timeout):
print "Arduino not ready, what is going on??"
print "Waiting another 10 seconds"
time.sleep(10)
if not ready_waiter(s, avail, timeout):
raise Exception("Arduino down for good.")
except IOError:
print "Could not open port. Is Arudino running?"
# we should be fine now
while True:
t, msg = pipe.recv()
if "HEARTBEAT" in msg:
# special case, try to update avail value if it's not available
if avail.value == 0:
ready_waiter(s, avail, timeout, retries=10)
if avail.value == 1:
avail.value = 0
time.sleep(1.0 / 10.0)
avail.value = 1
continue
if "TERMINATE" in msg:
print "exitting..."
return
if time.time() - t > timeout * 4:
print "Got msg {0} which is {1:.2f}s old, rejecting".format(msg, time.time() - t)
Logger.log_write("Rejected msg '{0}' as it was {1:.2f}s old".format(msg, time.time() - t))
continue
# print 'Trying to send msg "{0}"'.format(msg)
if "STOP" not in msg:
ready_waiter(s, avail, timeout, retries=2)
if avail.value == 0:
print "Can't send msg to arduino as it is not available, try again"
continue
avail.value = 0
if send_msg(s, msg, timeout, retries, "ACK"):
# print 'msg properly sent to arduino'
continue
