7mm scale GWR Tubular Signal

Working lights - smd warm white led (warm white leds show a green light through a blue lens as per prototype.

Powered by Tower Pro 9g servo motors controlled via a MERG Servo4 board running a modified Chris White sema4f firmware. The original sema4f has bounce as an option in both directions. I did not feel this to be prototypical and preferred the action of either the Megapoints or GF Controls board. However I preferred the greater control over speed and bounce of the MERG servo4.

However by a simple alteration of the firmware, I was able to have the arm bounce on return to Danger and hesitate slightly on moving to Clear in a similar way to the commercial offerings. In fact I prefer it .

Setup was implemented by using Chris Whites utility program which again, is MERG members only. Available to members as sema4h (I think), though you will of course need a Pickit 2 or similar to re-write the firmware to the microchip. If you are new to firmware, it is always best to re-generate the OSCCAL value but the PC alone probably won’t be up to it, so its best to power the microchip independently with 5vdc, otherwise it might fail. MERG members probably know all about this of course.

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