Hi,
I am new to Python. Trying to figure out how to use the serial port I
started with pyserial.
Works - but the CPU usage on my Raspberry Pi is at about 30% just for
reading the port. Before I started to optimize the code it was even 90+%.
So I tried twisted - and boom down to 3-4%. Even though twisted also uses
pyserial (as far as I read) - obviously better than I do.
So far so good.
With copy&paste from the internet and some editing I got the PI to read
from my Arduino. (code below)
But the code seems to be blocking. I tried putting things in a thread - but
I must have done something wrong. It is still blocking.
I also don't know how to write.
Does s.write("test") work?
Would be great if someone could help me out here.
Thanks a lot.
Robert
import logging
from twisted.protocols.basic import LineReceiver
from twisted.protocols.basic import LineReceiver
from twisted.internet import reactor
from twisted.internet.serialport import SerialPort
from twisted.python import usage
import thread
class THOptions(usage.Options):
optParameters = [
['baudrate', 'b', 115200, 'Serial baudrate'],
['port', 'p', '/dev/ttyACM0', 'Serial port to use'],]
class Echo(LineReceiver):
def processData(self, data):
print(data)
def lineReceived(self, line):
try:
data = line.rstrip()
#logging.debug(data)
self.processData(data)
#print(line.rstrip())
#pass
except ValueError:
logging.error('Unable to parse data %s' % line)
return
def SerialInit():
o = THOptions()
try:
o.parseOptions()
except usage.UsageError, errortext:
logging.error('%s %s' % (sys.argv[0], errortext))
logging.info('Try %s --help for usage details' % sys.argv[0])
raise SystemExit, 1
baudrate = o.opts['baudrate'] #int('115200')
port = o.opts['port']
logging.debug('About to open port %s' % port)
s = SerialPort(Echo(), port, reactor, baudrate=baudrate)
reactor.run()
thread.start_new_thread(SerialInit())
if __name__ == '__main__':
print("-----")
s.write('123456789')
#s.write("\n")
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