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Moon Clock power.
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Please be positive and constructive with your questions and comments.

Moon Clock power.

by keli on Sun Aug 15, 2021 2:15 pm

I've done a cursory forum check about Moon Clock power, didn't find an answer. I'm using a "64X32 RGB LED Matrix -5mmm pitch" display for it. What I don't understand is what "current" 5v power supply I should be using, one note says that a 64X32 display could use up to 4 amps. The BOM lists a 2.5 or 3 amp USB C corded wall wart that "plugs" into the "Adafruit Matrix Portal". I found another note that a 4 amp supply should be used with a 64x32 display, like a "5V 4A switching power supply" ($14.95). My confusion is there are 2 places you can connect voltage to, the "Matrix Portal" USB C port, or a set of screw onto power pads. I assume both rails are the same. So I could hook up a 5V 4A supply to the Matrix Portal USB C port, or to the screw on power pads on the Matrix Portal to power the clock (both Matrix Portal, and LED Matrix display). I assume the better connection would be to power the whole clock by applying 5V 4A supply to the screw onto power pads, no need to supply power to the SUB C connector? Keli

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Re: Moon Clock power.

by dastels on Sun Aug 15, 2021 3:27 pm

From looking at the schematic and inspecting the PSB, the 5v screw terminal and the 5v line on the USB-C connector are directly connected together. So, yes, you can power the panel and MatrixPortal by connecting a 5v supply to the 5c screw terminal. HOWEVER, don't connect the USB while 5v is connected to the screw terminal. There is no protection so bad things could happen to anything involved.

There's no advantage to powering one way vs the other. The "safest" is to go through the USB port.

Dave

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Re: Moon Clock power.

by keli on Sun Aug 15, 2021 4:03 pm

Thank you dastels for researching the Moon Clock power. Your answer brings up a problem I had not thought of. I normally like to leave the USB connector with power/data hooked up as I check the running program, figure out bug fixes then reprogram. Sounds like if I did that I might damage the clock with two power supplies hooked up. I thought as long as separate supplies had a "common" ground it would be OK. Keli

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Re: Moon Clock power.

by dastels on Sun Aug 15, 2021 4:48 pm

Separate supplies are fine if they have a common ground, but not a common power connection.

Dave

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Re: Moon Clock power.

by Harryshaw_12 on Fri Oct 08, 2021 12:49 pm

Its very important to cool the processor because heat increases the resistivity of metal conductors, hence causing cpu errors and reducing its speed exponontially. Most cpus therefore shutdown when the temperature crosses 100-120⁰C (not really sure about exact temp.) , so as to protect components from burning out position pipe for clock. Remember that these components are really really really small, so it doesn't take much to damage them.

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Please be positive and constructive with your questions and comments.