Linked Questions

2 votes
2 answers
367 views

Short pulse detection about 35ms, is it possible

I got somewhat short pulse 35ms, I written script in python using RPi.GPIO, using event and callback. Is it possible to detect so short pulses? On related question how close to 3V3 I need to get? I ...
windman's user avatar
  • 79
0 votes
3 answers
350 views

How to choose appropriate transistor and resistor values for the 4 digit display?

I bought this 4 digit led display I'm looking at this tutorial and I don't understand why he used such big resistor for his circuit. Excerpt: Please note that the pinouts of LED displays vary ...
hoenir's user avatar
  • 1
2 votes
2 answers
338 views

Multi-Joystick (Joystick, rotary Encoder, push Button) to GPIOs

I'm trying to connect a Joystick/Encoder/Button (Copal Electronics CJ25) to a Raspberry PI. Using gpiotest I managed to get it up and running pretty well - using 3.3V input (though the data sheet ...
ftw's user avatar
  • 33
0 votes
5 answers
296 views

Connecting 5V / 2A DC adapter positive line to GPIO

I have a working DIY UPS for my Raspberry PI 3B board. My requirement is that whenever the main power goes off the PI, the software should be able to detect it and immediately trigger a graceful ...
moosambi2020's user avatar
0 votes
1 answer
176 views

GPIO only reaches 2,4v when high

TLDR; Under little load the GPIO 22 reaches 3,5v whereas under more load it only reaches ~2,4V, which is not enough to trigger the reset-line on an ATMEGA328P. UART GPIO Pins still reach 3,3V in both ...
Jonas Zagatta's user avatar

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