Low trigger relay issues
The IO Pi Plus is a 32 channel MCP23017 GPIO expander for the Raspberry Pi
15/05/2024
Posted by:
nicusor.stoica
I am using a low level trigger relay board and when the power is lost the pins go low for a small period of time then everything goes back to normal, why is that happening? Or should I switch to a high level trigger relay board?
15/05/2024
Posted by:
nicusor.stoica
I meant to say when the power is lost and the system boots back up. I could post the code if necessary.
15/05/2024
Posted by:
andrew
Location:
United Kingdom
Hello
If the power is lost the MCP23017 IO chip will reset to its default state with the pins set to inputs, so any pin that was outputing a high level voltage will go to 0V.
Using a relay board with high level triggering or putting an inverter between the outputs on the IO Pi Plus and your relay board should fix the problem.
If the power is lost the MCP23017 IO chip will reset to its default state with the pins set to inputs, so any pin that was outputing a high level voltage will go to 0V.
Using a relay board with high level triggering or putting an inverter between the outputs on the IO Pi Plus and your relay board should fix the problem.
15/05/2024
Posted by:
nicusor.stoica
Quote from andrew
Hello
If the power is lost the MCP23017 IO chip will reset to its default state with the pins set to inputs, so any pin that was outputing a high level voltage will go to 0V.
Using a relay board with high level triggering or putting an inverter between the outputs on the IO Pi Plus and your relay board should fix the problem.
Thank you so much !
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