GPIO4 output 1,7 V at low

Diy and Tweaks Diy and Tweaks
1

Hi all,
I have installed current volumio on Rapi 4 B. I want to use GPIO4 (Pin 7) as output pin to realize an on/off switch. I connected to Pin 7 a resistor 270 Ohms and a LED to ground. Pin 7 is set up as output.

When the Raspi starts up, after a couple of seconds the LED is lit as wanted. When the Raspi shuts down, the LED goes out, but the voltage on Pin 7 is still 1,7 V. I expect it to be much lower. I would like to use it to switch off the voltage via a transistor and a relay.

What am I doing wrong?

Thanks, Rainer

2

The GPIO output is specified as:
< 1.8V => low
< 1.8V < 3.3V => High

To avoid problematic behaviors, you might opt for a relays board, designed for the rP, like;
https://www.amazon.nl/s?k=raspberry+pi+relay+board&adgrpid=101602624529&hvadid=593748258154&hvdev=c&hvlocphy=9065068&hvnetw=g&hvqmt=e&hvrand=5727792058430164819&hvtargid=kwd-295543861856&hydadcr=16567_2174938&tag=nltxtgostdde-21&ref=pd_sl_8lm8byapwh_e

3

Thank you. I did not know these voltage values. I have now connected a voltage divider in front of the transistor. Now it works :slight_smile: