Home ventilation controller with UNI questions regarding GND_SENSOR, GND, VCC_SENSOR

  • Hi ! I have succesfully got the UNI integrated with my garage door opener. I had a problem getting a low signal on the sensor input from my wiring to the garage controller - voltage fluctuated in closed position between 0.6-1.7 volt ). Solution was to use the ADC input and some coding in NodeRED - very flexible this little UNI.


    I am now going to replace my old arduino home ventilation controller with 2 UNI's and have some question for wiring.

    1. Are the GND_SENSOR and GND the same ?

    2. I am planing to drive the 4 pcs 5 volt relays that draws 10-15 mA using the VCC_SENSOR 3.3 volt. Does anyone know how much (mA) you can draw from the VCC_SENSOR ? ( Only one relay will be active at any time ).

  • Hello and welcome to the forum. :)


    Unfortunately I cannot answer your questions myself.


    But I hope DIYROLLY can help you.

  • Hello torfinn

    1. Door opener.

    The Voltage on Input is a lttle bit to high. it must be <1V

    You can use a little Circuit with a Diode and a Resistor (10-22kOhm)

    Diode from opener (anode) to input (kathode), then the resistor directly between GND_Sensor and the input.

    2. The GND_Sensor and Gnd are NOT the same.

    On Pin 1 VCC and 2 N are a rectifier.

    Wenn you want to measure Voltage over Adc you must use GND_Sensor for DC GND, Pin 2 it not used (open)

    3. Do not use 3,3V for relays, the current for this its to low and on Relays it give a short Voltage Peak.

    For 5V Relay you can use the 12 oder 24V DC from Uni and a resistor for each Relay.

    Example Resitor Relay: 12V Power - Relay 5V = 7V

    R = U / I. 7V / 0,015 A = 466 Ohm, ~ 470 Ohm in series con.