1. Alan_uk

    Circuit B opto-coupler upsets Circuit A opto-couplers

    Hi. I have built an interface between a Raspi 4 and an Alarm Panel with some extra add ons. The diagram below shows 3 circuits A, B & C. Circuit A at the top has 8 inputs from the alarm panel (12v) and feeds them through 8 optocouplers (2 x 4 modules) - note the internal 3K resistors and...
  2. S

    Connecting 12V Inductive Sensor to Raspberry Pi 3B+

    Hello, I am not too strong with building electrical circuits so I am just wondering if I could get some feedback on the circuit I built. I am trying to connect a 12V inductive sensor to a Raspberry Pi 3B+ 3.3V port. The inductive sensor is being used to detect a metal sleeve inside of a valve...
  3. LordOfThunder

    Convert digital signal from TTL 5V to Raspberry Pi GPIO 3.3V

    Hello! I am a Ph.D. student in particle physics and for our experiment we need to convert a 5V TTL digital signal (16-bits actually) coming out of a Phillips 726 converter and read it using the GPIO pins of a Raspberry Pi 4. We do not need bidirectional communication. We just need to read this...