Project: simple thermostat

Your habitat module should stay warm, and you want to change the target without touching the code. Everything you need you know from this week and the previous ones: set instructions, select, min, max and round.

The setup#

The target in the housing#

The program reads the target from db Setting, in degrees Celsius. In the game it later comes from another device or chip, in the simulator you set it by hand. Two safeguards belong to it:

• If the housing still holds 0, 20 °C applies. That way a freshly inserted chip does not cool the room down to 0 °C.
• The target is limited to 5 to 35 °C. A typo like 300 does not turn the module into a sauna.

l r1 db Setting        # target in C
seqz r2 r1             # 1 = nothing entered
select r1 r2 20 r1     # then 20 C
max r1 r1 5
min r1 r1 35

Heating and colour#

The heater runs when it is more than 1 °C colder than the target. A real hysteresis with memory comes in week 7, today the band from week 4 is enough.

The display shows the temperature in °C with one decimal, mode Celsius, and takes on a colour:

Two select in a row do that. The second overwrites the first when the heater is running:

select r6 r5 4 2       # red or green
select r6 r4 0 r6      # blue while heating

Milestones#

1. Cold: heater on.
2. Warm enough: heater off, display green.
3. Display in °C with one decimal, mode Celsius.
4. Blue while heating, red when too warm.
5. Without a target 20 °C applies.
6. Target limited to 5 to 35 °C.