SolarPostion Library

[Rollmop]

Hello, I am try to use Ken Willmott Solar Postion Library to tell if the sun is up or down to turn a light on.

my question is how can I turn the (pos.elevation, numDigits) into a usable variable I can do a simple if <=0 check on to see if it is up or down.

If I set Float Solar_elevation = (SolarPosition_t pos, int numDigits) it returns 3 (the numDigits)

[jremington]

Try

if (pos.elevation < 0) do_something();`

Here:

float Solar_elevation = (SolarPosition_t pos, int numDigits) it returns 3 (the numDigits)

Correct. Look up "C/C++ comma operator" to learn why. Specific to the Serial.print case, the "3" is a function call argument that determines how many digits to print.

[Rollmop]

That sorted that problem now the rest

Thank You.

I'll know what i am doing one day

[TomGeorge]

Hi,
It seems a bit elaborate a project that an LDR and some control logic can do instead.

LDR is daylight saving proof, longitude proof.

Tom...

[johnwasser]

@Rollmop

do a simple if <=0 check on to see if it is up or down.

Note that the sky is quite light when the center of the sun is on the horizon (elevation = 0°). You may want to check for civil (-9°), nautical (-12°) or astronomical (-18°) twilight.

[Rollmop]

Thanks John thats good to know

[Rollmop]

Who says it does have an LDR too......

[TomGeorge]

Hi,

@Rollmop

Who says it does have an LDR too......

What is the scope of your project?
You just say you want to turn a light ON/OFF, in response to the sun being above and below the horizon, what other stuff is the controller connected to?

Tom...