This is used on machinery to collect data points. The opto isolator board is 24 vdc to 3.3vdc. when 24 volts applied to board, it will be a zero on the RPI GPIO so you must 'not' every test. We order the opto board from Amazon.com along with the RPI.

DST-1R4P-N 24vdc to 3.3vdc opti-coupler for use with Raspberry-pi and other 3.3v input microprocessors.

OPTO-ISOLATOR

Welcome to your new project. Imagine what you can build here.

Welcome to your new project. Imagine what you can build here.

An example development and reference design for the ESP32 microcontroller.

A simulated circuit that demonstrates how diodes in a bridge configuration convert an AC voltage to DC voltage.

A preliminary design for developing SMT32F4x series based project that’ll help you get started faster.

A simulated blinking LED circuit using an astable multivibrator a.k.a "flip-flop" as a square wave generator.

Two separate simulated circuits which demonstrate how step up and step down transformers work.