What resistors and capacitors will I need?
In this circuit the subsequent LED won't start its RC timer until the previous LED lights, so all time constants can be the same (0.1 sec, approx 1M and 0.1uF, adjust as necessary). The buffer needs to be non-inverting (could be a quad OR or AND) and capable of supplying the LED current (4 * about 5mA each). The LEDs will snap on at even intervals, not fade in.



simulate this circuit &ndash; Schematic created using CircuitLab