Hello friends! Today we will build an LED flashing circuit using a 555 timer in Proteus ISIS. We will start with one LED, calculate its on and off times, and then connect two LEDs so they alternate. No microcontroller program is needed because the timer and its resistor-capacitor network generate the repeating signal. This is a useful first electronics project because you can see the result while also measuring the signal that produces it. We will connect the circuit step by step, examine the timing capacitor voltage, and compare the calculated period with the waveform in the simulator. The original diagrams and downloads remain in this tutorial. Some historical connections differ from the recommended arrangement described below, so we will identify those differences explicitly. If you are ...