PaulS:
const int DS18S20_Pin=1;
const int ssrPin=0;
const int upPin=9;
const int downPin=10;
const int Setpoint_address=0;
At least some of these could be bytes.
Sorry for off topic, but I've been told (and then, I verified) that const int's, like #define's, doesn't use any memory. So... why changing const int to const byte would save memory?