ATOM HUB AC/DC, RS-485 VOLTAGE CONVERTER, VOLTAGE PROBLEM



  • I am working on a project where the switch is controlled by the M5 PIR SENSOR.
    When I power the ATOM from USB everything works fine, when I power it with a 12V 3A PSU thought the RS485 voltage converter the PIR begins malfunctioning (fake triggers).

    I checked the voltage of the two groove outputs (from the hub and from the atom lite) under USB and 12V power. As long as USB is connected, the interfaces shows a quite stable 4.98V.
    When the USB is unplugged, leaving only the 12V power source, the voltage drops to 3.3-3.28V, if the atom is removed it goes back to 5V
    I guess this is causing the PIR to misbehave, since it requires 5V.

    What´s wrong?
    According to labels on the components and to the HUB schematics, I expect 5V 2A from the DC/DC converter.

    0_1617022207056_1.jpg
    0_1617022213126_2.jpg
    0_1617022220086_3.jpg
    0_1617022224454_4.jpg
    0_1617022236413_IMG_20210329_144131.jpg

    0_1617022270513_Switch_schem.JPG



  • Hi it seem you are powering the 12v wrongly.

    Based on sticker of the HUB, red is 12v and black is gnd.

    Hope this helps

    Jason



  • @kine90 said in ATOM HUB AC/DC, RS-485 VOLTAGE CONVERTER, VOLTAGE PROBLEM:

    I am working on a project where the switch is controlled by the M5 PIR SENSOR.
    When I power the ATOM from USB everything works fine, when I power it with a 12V 3A PSU thought the RS485 voltage converter the PIR begins malfunctioning (fake triggers).

    I checked the voltage of the two groove outputs (from the hub and from the atom lite) under USB and 12V power. As long as USB is connected, the interfaces shows a quite stable 4.98V.
    When the USB is unplugged, leaving only the 12V power source, the voltage drops to 3.3-3.28V, if the atom is removed it goes back to 5V
    I guess this is causing the PIR to misbehave, since it requires 5V.

    What´s wrong?
    According to labels on the components and to the HUB schematics, I expect 5V 2A from the DC/DC converter.

    0_1617022207056_1.jpg
    0_1617022213126_2.jpg
    0_1617022220086_3.jpg
    0_1617022224454_4.jpg
    0_1617022236413_IMG_20210329_144131.jpg

    0_1617022270513_Switch_schem.JPG

    Based on your photo's you haven't connected the 12V to the correct pins of the RS485 connection.
    12V needs to be connected to the RS485's red and black pins.