i2c.py, ValueError, out of range 0-256 in writing_bytes #49
Description
Not sure what causes this problem, but I'd though it might be useful to at least post an issue report.
I tried using the quick2wire library with a cheap accelerometer by running the following code:
from i2clibraries import i2c_adxl345
adxl345 = i2c_adxl345.i2c_adxl345(0)But immediately I get the following error:
Traceback (most recent call last):
File "./test1.py", line 6, in <module>
adxl345 = i2c_adxl345.i2c_adxl345(0)
File "/home/pi/projectfolder/i2clibraries/i2c_adxl345.py", line 100, in __init__
self.setActivityThreshold()
File "/home/pi/projectfolder/i2clibraries/i2c_adxl345.py", line 178, in setActivityThreshold
self.setOption(self.ActivityThreshold, intervals)
File "/home/pi/projectfolder/i2clibraries/i2c_adxl345.py", line 230, in setOption
self.bus.write_byte(register, options)
File "/home/pi/projectfolder/i2clibraries/i2c.py", line 14, in write_byte
writing_bytes(self.addr, *bytes))
File "/home/pi/projectfolder/quick2wire-python-api/quick2wire/i2c.py", line 97, in writing_bytes
return writing(addr, bytes)
File "/home/pi/projectfolder/quick2wire-python-api/quick2wire/i2c.py", line 108, in writing
buf = bytes(byte_seq)
ValueError: bytes must be in range(0, 256)
Printing these values, I noticed at least one of them indeed isn't in this range: -3
As a quick hack I changed the function in i2c.py so it clamps the values in byte_seq before returning the message, after which everything works perfectly.
def writing(addr, byte_seq):
lst = list(byte_seq)
for i in range(0, len(lst)):
lst[i] = max(0, min(255, lst[i]))
byte_seq = tuple(lst)
buf = bytes(byte_seq)
return _new_i2c_msg(addr, 0, create_string_buffer(buf, len(buf)))