Category Archives: Automation

New things! Everything is progressing nicely. Did additional testing on the 230VAC detection circuit and wrote software to read SHT31 digital humidity/temperature sensors. Also added a ClosedLoop function so analog inputs can be used to compare to store values and have an outputs act on the comparison.

230VAC detection

Finally I had the time to properly measure the mains voltage inputs. No shorts or anything… So I decided to go on and plug in the mains voltage into the Artemis.

The 230VAC detection circuit is connected to D48 (ICP5 on the Arduino), which mean I could potentially measure the exact frequency of the mains AC voltage. Still, I do not require to have that, so instead I built a simple timer that resets if the phase comes up, and counts down if the phase disappears. This way I always have a stable reading on the signal, even when the Artemis accidentally measures on an exact phase zero crossing.

        if (digitalRead(PIN_230V_DETECT) == LOW) // Active? Reset Timer.
        {
                TIM_50HzDetect = 10;
        }
        else
        {
                if (TIM_50HzDetect) // Not active -> count 2 zero and stay.
                {
                        TIM_50HzDetect--;
                }
        }