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I had to design a board for a customer with a built in LTE modem module (similar to a SIM800), and the power circuitry was something that required special consideration. One requirement of the board was that the modem should be able to be powered on and off to save power, but that powering it on shouldn't ever cause the rest of the board to brownout. To ...


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You can tell it's a fake Uno because the USB chip is not an Atmega32U4.


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Chances are the cheap Chinese clone board you have has an inferior 5V regulator with no thermal protection. These are notorious for breaking with a short circuit (over-current = over-temperature = meltdown). And when they break they "fail short", which means that they end up working like a simple piece of wire - the voltage you put in is the voltage you ...


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The regualator of that 5V Blew up or the diode you need to read the schemtics of the Arduino Uno and check the circuits. https://www.arduino.cc/en/uploads/Main/arduino-uno-schematic.pdf


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I am usually using 12V/1000 mA adapter source to power Arduino and adjustable step-down/buck converter which powers GPS and similar modules. Advantage of this is that these converters usually have big capacitors on input and output, so you do not have to use additional auxiliary capacitors.


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The cleanest solution is to use separate power supplies for your MCU and your other high power devices. Get a 2.5A supply for the SIM800L, and a more modest supply for the Arduino/NodeMCU. If you use the same power supply for both, you should use a bigger power supply than your max current needs to minimize "droop" as the load changes. You might also need ...


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The entire circuit board, including the LM393, power light and it's resistor, uses 2.2 mA at 3.3 VDC (4.12 mA at 5 VDC). Once the comparator is "triggered", the "D0-LED" and it's associated resistor come in to play which bumps the current up to 3.6 mA at 3.3 VDC (7.82 mA at 5 VDC). I think it would be OK to use digitalWrite(pin_number, HIGH) to power the ...


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The JSN-SR04T-2.0 ultrasonic range finder is rated to 5Volts. giving it 3.3 volts may not be enough. from my limited knowledge it should work if you give it a separate power supply and not depend on the 3.3 volts of the ESP.


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The module may very well be dead now, due to giving it 5V. But depending on which board the module is mounted on, there might be a voltage regulator that expects 5V. Check the specifications for the board you bought. A window means that at least 50% of the sky is blocked by the building. The module might not be able to get a signal from enough satellites ...


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Probably not. There is nothing fundamentally wrong with what you're doing - it's within the design parameters. In particular: 12V is within the 7-12V recommended range specified for that input. Yes, it means the regulator will get hotter, but the AMS1117 is supposed to be current limited and thermally limited so should just start shutting down if it ...


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