Project: light scenes

The workshop has four rows of lights. During the day everything should be bright, dimmed in the evening, only one row at night. When the emergency power runs, only a flickering emergency light remains. The whole thing is operated with a single button.

The plant#

The scenes#

Every press of the button moves on one scene, after 3 comes 0 again. The table sits in the stack via poke before the main loop, get target db scene fetches the number of groups.

The button reports Activate = 1 as long as it is held down. So that a long press does not step on every tick, only the edge counts – the change from 0 to 1:

sgt tmp button last   # 1 only in the first tick of the press
move last button
add scene scene tmp
mod scene scene SCENES

Smooth dimming – with honest lights#

In the game lights only know On, there is no dimmable light. So “smooth” means here: the groups switch on or off one after another, one per second. A level from 0 to 4 runs towards the scene’s target, group k is lit as long as the level is at least k:

sub tmp target level
sgn tmp tmp           # -1, 0 or 1
add level level tmp   # one step towards the target
sge lit level 3       # group 3 on from level 3

A counter makes sure the level only takes a step every TICKS ticks. It may keep running when the level has already reached the target: the difference is 0 then, and sgn returns 0.

Emergency light#

When the lever “Notstrom” is at 1, groups 2 to 4 go off. Group 1 flickers: every tick rand decides whether it is lit, with a probability of 70 %. Put the lever back and the scene returns.

Milestones#

1. Scenes via the button, on the edge only, the display shows the number
2. Smooth dimming: one group after the other, up and down
3. Emergency light: group 1 flickers, groups 2 to 4 are off
4. Failure: without the lever normal operation applies; without the button the scene stays