Added readme

README.md

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+# Obituary PCB
+
+This is a functional artwork PCB for an obituary.
+
+It was made in memory of our dear friend Obri, who has passed away way too soon on May 29 2020.
+
+
+## Artwork
+
+Aside from the circuit itself (wherin lies the beauty of the PCB), the two logos of CCC Basel and CCC-CH are printed on top.
+
+There is an empty area in the middle, intended for the obituary text.
+
+For a rendering on paper, it is recommended to only print the F.Cu and Eco1.User layers.
+
+
+## Circuit description
+
+This circuit is a simple LED chase with 6 steps, based on the NE556 dual timer and a 74HC273 8-bit register.
+
+The LEDs are driven by six 2N7002 small-signal MOS-FETs that should provide ample current for a series of LEDs.
+
+A 74HC32 quad or gate is used together with one of the timers to initialize the LED sequence.
+The timer generates an initial 750ms pulse that switches off after the sequence is latched into the register.
+To achieve this, it is configured for monostable operation, with the trigger connected to an RC circuit that will disengage after ~0.1ms.
+
+The second timer generates the clock signal that shifts the sequence forward. It is tuned for clock frequency of 1Hz.
+
+To change the clock frequency, three resistors need to be changed: R2 for the initialization pulse and R3 and R4 for the clock frequency.
+The initialization pulse should be roughly 0.75 times the clock period, so it switches off after the first positive clock edge.
+
+If the initialization pulse must be shorter than 0.1ms, you also need to adjust the trigger pulse.
+Simply tune the RC circuit formed by R1 and C1 so its T value (= R · C) is roughly the pulse time.