CODEWITHSUNDEEP
python-3.xclass
dumbhacker
dumbhacker

Reputation: 9

Calling a method <name> I get AttributeError: 'int' object has no attribute <name>

I have a callback method being triggered on a GPIO pin that when fired calls for a read of a input devices register, however when called I get -

Traceback (most recent call last): File "/home/coder/Try2.py", line 35, in NewPins x = self.mcp.readGPIO() AttributeError: 'int' object has no attribute 'mcp'

If I enter- a.mcp.readGPIO() <- from python shell I get

`BitArray('0xffff')`  <-expected result
>>>

where the RotaryEncoder class is instantiated as 'a'

 `class RotaryEncoder:`
   `def __init__(self,IntPin, Start, Id):`
     .... initialise some variables then open the device as 'mcp' -
   `self.mcp = MCP23S17(bus=0x00, pin_cs=0x00, device_id=Id)`
   `self.mcp.open()`
   `def NewPins(self):`
   `   global OldPins`
   `   x = self.mcp.readGPIO()`
        ..... irrelevant code

callback line is gpio.add_event_detect(IntPin, gpio.FALLING, callback=NewPins)

expected read value is a BitArray actual result is AttributeError: 'int' object has no attribute 'mcp'

Upvotes: 0

Views: 300

Answers (1)

dumbhacker
dumbhacker

Reputation: 9

Ok my dumb.... - the RPiGPIO library I'm using returns the GPIO channel number in the callback, hence the callback function requires two arguments and not one. I had thought I'd messed up my namespaces and so was trying to code around this when I encountered the error above - I'm a novice python programmer and didn't know where to look! That'll teach me to not to read the documentation thoroughly...

Upvotes: 0

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