ehabzaky
Junior Member level 3
Dear All,
It may be very basic question but I need help to understand it please.
I have a human sensor which simply send 3.3 volts output once a human movement is detected. I'm connecting this output directly to a MCP23S17 to detect this signal and further process it through Raspberry PI. Up to here everything is OK.
I want to put an LED to give visual indication of human sensor action. When I connect the output of the human sensor to an LED with a resistor it was lighting OK but the MCP23S17 no longer detect the signal as per the following diagram. It seems that the current is going through the LED path only.
![inputled.png inputled.png](https://www.edaboard.com/data/attachments/56/56536-a9b59d1f5370ac8abfdb9cad40fcbfb2.jpg)
Could someone guide me how to have both LED working on signal and MCP23S17 detect it?
Regards,
It may be very basic question but I need help to understand it please.
I have a human sensor which simply send 3.3 volts output once a human movement is detected. I'm connecting this output directly to a MCP23S17 to detect this signal and further process it through Raspberry PI. Up to here everything is OK.
I want to put an LED to give visual indication of human sensor action. When I connect the output of the human sensor to an LED with a resistor it was lighting OK but the MCP23S17 no longer detect the signal as per the following diagram. It seems that the current is going through the LED path only.
![inputled.png inputled.png](https://www.edaboard.com/data/attachments/56/56536-a9b59d1f5370ac8abfdb9cad40fcbfb2.jpg)
Could someone guide me how to have both LED working on signal and MCP23S17 detect it?
Regards,