IO Pi Plus and Codesys
1100 Views - Created 17/09/2020
II am using IO Pi Plus with my Rasypberry and have some problems. I am using it as digital outputs, but there is always 5V on piout even if I change the state.
I am using this library for Codesys
I don't have any experience developing with Codesys so I can't help you with their MCP23017 library.
Can you try testing the IO Pi Plus with our Python library and see if it works correctly? There is a demo file called demo_iowrite.py in the ABElectronics_Python_Libraries/IOPi/demos/ folder that should write to the digital outputs on the IO Pi Plus.
If the demo files work you can narrow the problem down to the Codesys library, in which case you may find more help on the Codesys forums.
I was testing this and I do not think this is a library problem.
If I startup my RPI and IO board at the same time I can not operate with outputs. There is 5V on every pin on this board. But If I startup Raspberry PI first and this IO board in about 10s, I can operate with outputs normal.
If you are using two power supplies, when they are switched on the IO Pi supply may reach 5V before the Raspberry Pi supply which could be causing this issue. To get around this issue you may need to find a way of starting the Raspberry Pi power supply before the IO Pi supply so the Raspberry Pi is already initialised when the IO Pi powers up.
Note: documents in Portable Document Format (PDF) require Adobe Acrobat Reader 5.0 or higher to view, download Adobe Acrobat Reader or other PDF reading software for your computer or mobile device.