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3

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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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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