10TFF module v2

A project log for Yet Another (Discrete) Clock

I HAD to finally do this basic "exercice de style" in digital electronics, using some hundreds of transistors and diodes...

yann-guidon-ygdesYann Guidon / YGDES 07/08/2016 at 07:550 Comments

I just submitted a new PCB job for the 2nd version of the 10TFF module.

I found a short in the precedent version, fortunately I could submit a correction :-)

I also found a solution to the reset problem. The 24H board has a 3-stages 1-hot shift register instead of a 6-stages Johnson counter. There are 2 differences: the outputs are swapped for the Johnson counter and the 1-hot has one 10TFF reset to state 1. Swapping is determined by jumpers on the HMS boards but reset to 1 has been a bit tricky. The solution is simple in the end: one 10TFF module has specific wiring of the diode, which is connected to the complementary signal. The module is already too crowded to allow the modification but it's easy to rewire just one of the modules with a short wire.

The swapping of the 3-stages shift register will be selected with solder pads.