I'm new to python and I'm trying to loop through all 255 addresses to locate a specific bit of hardware over RS485. The hardware is attached, and it's address is supposed to be 0x25, but this is not the case, so I need to find what its address is.
So far I've got:
def Init_Sync_4 ():
GPIO.output(18,GPIO.HIGH)
ser.write([CID,0x17,0x20,0x01,0x14,0x1c,0x04,0x00,0x00,0x00,0x00,0x00,0x32,0x00,0x01,0x00,0x00,0x00,0x32,0x00,0x02,0x00,0x00,0$
time.sleep(0.007)
GPIO.output(18,GPIO.LOW)
and
ser=serial.Serial(port='/dev/serial0',baudrate=38400,stopbits=2,timeout=1)
GPIO.setmode(GPIO.BCM)
GPIO.setup(18,GPIO.OUT)
GPIO.output(18,GPIO.LOW)
for i in range(0xff):
CID = '0x{:02x}'.format(i).encode('ascii')
print "at address %s" % CID
Init_Sync_4()
time.sleep(0.05)
Init_2()
time.sleep(0.05)
Here CID is the address being built, which Init_Sync_4() uses in it's byte array in ser.write, but I keep getting the error:
at address 0x00
Traceback (most recent call last):
File "rs485_test_2.py", line 97, in <module>
Init_4()
File "rs485_test_2.py", line 40, in Init_4
ser.write([CID,0x17,0x20,0x01,0x14,0x1c,0x04,0x00,0x00,0x00,0x00,0x00,0x32,0x00,0x01,0x00,0x00,0x00,0x32,0x00,0x02,0x00,0x00,0x00,0x00])
File "/usr/lib/python2.7/dist-packages/serial/serialposix.py", line 518, in write
d = to_bytes(data)
File "/usr/lib/python2.7/dist-packages/serial/serialutil.py", line 66, in to_bytes
return bytes(bytearray(seq))
ValueError: string must be of size 1
I'm assuming that it's still being passed as a string, when it needs to be a single byte, but I'm lost at how the conversion would work. I've checked out some SO pages, that specify using .encode with or without params, but I'm either using it incorrectly, or it's not quite what I'm after. Any help is greatly appreciated! Thanks.
