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No. You must connect AVcc even if you're not using the ADC. According to the datasheet: AVCC is the supply voltage pin for the A/D Converter, Port C (3:0), and ADC (7:6). It should be externally connected to VCC, even if the ADC is not used. If the ADC is used, it should be connected to VCC through a low-pass filter. Note that Port C (5:4) use digital ...


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Linear regulators such as the 7805 operate by dissipating the additional voltage until their rated voltage remains. This - as you noticed - requires a higher voltage than the rated voltage. Some variants, labeled as LDO for low drop-out, have reduced requirements for this, but normal 7805 usually require around 7 V to operate correctly. The difference to ...


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I don't even know how many amps "24VAC" is Exactly, because that's a voltage rating (24 Volts AC) and no information about the current capability is given. I've found 24VAC to 12VDC converters (made for surveillance cameras) online, but most are rated for 1.5A, and I'd be concerned about frying the Arduino. I am not sure if the Arduino only pulls as much ...


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No, the datasheet says power must be connected to Avcc. This is from the '328P, Atmega8A is similar but with less memory: (Microchip is taking forever to open the Atmega8A datasheet for me). 5.2.7 AVCC AVCC is the supply voltage pin for the A/D Converter (ADC), PC[3:0], and PE[3:2]. It should be externally connected to VCC, even if the ADC is not used. ...


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I suggest using a DC-DC buck/boost voltage regulator. Those can take a wide range of input voltages and put out an adjustable output voltage This one on Amazon, for example, can take an input of 3-40V and provide an output of 1.5-35V(Adjustable). It is a switching power supply, so it should not produce much waste heat. That one is rated at 2A, or 3A if you ...


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1W is near the limit of what a small LDO can handle. It will get considerably hot. I would use 4 batteries instead of 5, and a 3.3V Arduino clone instead of the UNO, and power the LEDs directly from the batteries. You could also use your original UNO, feeding it with 6V on a 5V pin through a simple diode, which would drop it to something like 5.4..5.3V.


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Use en external voltage regulator (go switch-mode if you care about battery life) that is adequately cooled.


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As others have said, an Arduino pin can't handle 12V, and can't handle anywhere near 10A of current directly. A digital pin on an Arduino is limited to 20mA, or 1/500 as much current as you need, at 5V, which is less than half the voltage you need. If you try to connect 12V to a pin on an Arduino pin you will almost certainly destroy that pin, and may ...


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The lab power supply you linked is serious overkill for your needs. It shouldn't need a separate voltage regulator or buck converter, since I assume that it provdes a voltage and current regulated supply. A regulated, fixed voltage 4V power supply that can provide 2A is what you want. That will probably cost < 1/10 of the amount of the lab supply you ...


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