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ExpanderPi stopped working

1616 Views - Created 21/04/2016

21/04/2016

Posted by:
tfv3

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I have and ExpanderPi sitting on a Rasperry, monitoring some inputs. Worked well for some weeks, after a power switch on and off two days ago it stopped working.

I have disconnected all IOs now, but get an ErrrNo 5 even trying to run your tester.py program.

Does that mean that a simply switching off the Raspi has grilled the board?

21/04/2016

Posted by:
andrew

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Location:
United Kingdom

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Switching off the Raspberry Pi should not cause any damage to the Expander Pi.

Can you try running sudo i2cdetect -y 1 and see if any of the devices on the Expander Pi are listed?  The addresses 0x20 for the IO chip and 0x68 for the RTC should appear.  Can you also try running some of the demo scripts from our python library.  demo-adcread.py will read the ADC inputs and show if the SPI bus is communicating. demo-ioread.py will test the IO chip and demo-rtcsetdate.py will try to talk to the RTC.  

If both the IO and RTC scripts do not work then it is likely to be a software problem which has caused the I2C bus to stop working.  If only one of the devices has stopped working then it could a hardware fault in which case I will send you a replacement.  It may be worth using a second SD card to set up a fresh image of Raspian linux and follow our I2C and SPI tutorials to enable the buses.  With a fresh install you can download the python library from github and rule out any software problems on your current linux install.

AB Electronics UK Tech Support

28/04/2016

Posted by:
tfv3

Last edited: 28/04/2016

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sudo i2cdetect -y 1 only shows 68, but not 20. What does that tell me?

demo-adcread.py words and read input values (0.0, have not checked whether this is correct)

demo-ioread.py stops with Err 5 in line 211:

Traceback (most recent call last):
  File "demo-ioread.py", line 26, in
    io = IO(bus)
  File "/home/pi/Python/ABElectronics_Python_Libraries/ExpanderPi/ABE_ExpanderPi.py", line 211, in __init__
    self._bus.write_byte_data(self.__ioaddress, self.IOCON, self.__ioconfig)
IOError: [Errno 5] Input/output error

demo-rtcsetdate.py returns a time.

I have meanwhile ordered a new part, can you nevertheless send me a replacement for the old one so that I have a spare in case of another failure? I'll send an email referring to this post.

___

Some additional info: We have optically decoupled IOs at the binary inputs and outputs, so every trouble will most likely have entered via power supply.

 

 

 

 

 

28/04/2016

Posted by:
andrew

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Location:
United Kingdom

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From what you have described it does sound like the IO chip is dead so I will send you a new Expander Pi tommorow.  I believe Brian sent you an email earlier, he had not seen your post on here so he didn't know that you have already tested all of the chips on the I2C bus.

The new board should be with you in a few days.

 

AB Electronics UK Tech Support

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