Should the library be built independently and not via pip tool?

[mglowinski93]

Hi, I've a question about proper installation of this library.

For the first attempt I installed it by pip install vl53l1x==0.0.5. In this case, I noticed that debug information appears (see https://github.com/pimoroni/vl53l1x-python/issues/47) and that exceptions will not be raised when the device is not active (see below code snippet):

OSError: [Errno 121] Remote I/O error
Traceback (most recent call last):
  File "_ctypes/callbacks.c", line 232, in 'calling callback function'
  File "/home/pi/.local/share/virtualenvs/PlugsTester-EektgUbj/lib/python3.7/site-packages/VL53L1X.py", line 142, in _i2c_write
    self._i2c.i2c_rdwr(msg_w)
  File "/home/pi/.local/share/virtualenvs/PlugsTester-EektgUbj/lib/python3.7/site-packages/smbus2/smbus2.py", line 658, in i2c_rdwr
    ioctl(self.fd, I2C_RDWR, ioctl_data)
OSError: [Errno 121] Remote I/O erro
VL53L1X Start Ranging Address 0x29

VL53L0X_GetDeviceInfo:
Device Name : VL53L1 cut1.1
Device Type : VL53L1
Device ID : 
ProductRevisionMajor : 1
ProductRevisionMinor : 15

Distance: 100 cm

That is something what I would like to avoid, in other words to fail the script when device is not available.

I know there is the logic for validating the sensor availability while creating object, but what in case it will become unavailable during measurements?

        try:
            if tca9548a_num == 255:
                self._i2c.read_byte_data(self.i2c_address, 0x00)
        except IOError:
            raise RuntimeError("VL53L1X not found on adddress: {:02x}".format(self.i2c_address))

So I decided to build a package on my own. I've downloaded this repository and executed python setup.py build. I can see a library vl53l1x_python.so file inside build folder. Once I move VL53L1X.py and distance.py to build folder I can successfully communicate with the sensor and DEBUG output is not printed. I guess because I've build it without -DDEBUG flad as mentioned in https://github.com/pimoroni/vl53l1x-python/pull/39.

Nevertheless, I still can't get the script failing when device is not available. So I've two questions: 1) Should i rather build package on my own or install it with pip? 2) How to make script fail when there is an exception?

[Gadgetoid]

Looks like I need to publish a new release via pip, v0.0.5 doesn't include the latest changes.

The error you want to catch when a sensor is unplugged or unavailable is probably OSError:

Traceback (most recent call last):
  File "/home/pi/Documents/vl53l1x-python/python/VL53L1X.py", line 145, in _i2c_write
    self._i2c.i2c_rdwr(msg_w)
  File "/usr/local/lib/python3.9/dist-packages/smbus2/smbus2.py", line 658, in i2c_rdwr
    ioctl(self.fd, I2C_RDWR, ioctl_data)
OSError: [Errno 121] Remote I/O error
Distance: -1mm

[mglowinski93]

I've already found workaround :) But thanks anyway, good that you aware about this issue.