I have no problem turning on and off pins on my rpi4 (using both gpio on the terminal and Gpiozero with python3) however when I connect a wire (which is connected to a switch) to the pin... it turns the pin output to 0. When I disconnect, it goes back to 1.
What is the deal here? When I take the connection and attach it to an always on 5V pin - the switch turns on!
Any thoughts?
Question
Experiment
(1) Rpi4B terminal command Gpio and Python GpioZero can set GPIO pin output High or Low level.
(2) GPIO pin if connected to a (push button or toggle) switch can set Gpio pin output to Low.
(3) If switch in (2) is disconnected, GPIO pin output goes High level again.
(4) If GPIO pin connected to Rpi 40 pin connector's 5V power output (Pins 2, 4) GPIO pin output becomes High level again.
Legend
(a) High (logical) level means Rpi finds GPIO pin (physical, electrical) voltage ~= 3.3V (or ~= 5.0V)
(b) Low (logical) level means Rpi finds GPIO pin voltage ~= 0.0V
(c) High = 1 = 'turn on', Low = 0 = 'Turn Off'
Question
What is the deal here? When I take the connection and attach it to an always on 5V pin - the turns on! Any thoughts?
Answer
There is no big deal. If Rpi GPIO pin is connected to 5V, it is getting warmer and warmer (should not seeing smoke or flame, or hearing a pop or a bang), just dying slowing frying (geek talk = "silicon up latching").
References
Latching Up Forum Discussions
(1) DHT11 sensor and the wrong voltage may have fried my RPi3
(3) https://www.raspberrypi.org/forums/viewtopic.php?f=56&t=232411&p=1426931&hilit=latching+up#p1426931
(4) https://www.raspberrypi.org/forums/viewtopic.php?f=56&t=232411&p=1424642&hilit=latching+up#p1424642
.END
