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5

1A coming in thru the barrel jack connecor, then you risk blowing the 1A rated reverse polarity protection diode. The 5V regulator will overheat at high currents above 7.5V. The chip itself can have 800mA put thru if if properly cooled and the IO limits of current per port are respected. So 1.6A, no way.


4

The VIN pin goes to a 5V voltage regulator on the Arduino and needs at least about 7V minimum to work properly. If you want to supply 5V to an Arduino do it either on the 5V pin or via the USB connector. The VIN pin should receive 7V to 12V.


3

The old circuit will not work as you expect. While the ATtiny85 can run happily with 2.7 to 5.5V in this setup it expects 5V. I assume this is due to the high CPU clock setting. To run stable at a high CPU clock it requires 4.5V. The VIN pin is connected to a linear regulator that has a 2V drop-out. Thus the supplied voltage has to be at least 2V about the ...


3

Assuming you are using a 9V block battery: They don't deliver the current you need for the esp32 to run/create an access point/act as a client. What you can do is connect 6 AA batteries in a row (6*1.5V = 9V) and they will deliver a higher current than the 9V block.


3

The power consumption is part of the exchange with the PC when it is plugged in. You can change that. Find the file USBCore.h in your Arduino install directory. In my case (under Linux) it was: ./hardware/arduino/avr/cores/arduino/USBCore.h Inside that file, at around line 269 (depending on the distribution) you should see these lines: #define D_CONFIG(...


3

You can make -5 V if you use an external power source, like in the circuit below (untested). Connect the GND (-) from the Arduino to the +5V from the External (5V) source, than 0V will be the GND (with respect to the Arduino), but the GND of the external source will be -5V with respect to the Arduino. I only used the resistors to get no short circuits, you ...


3

While it may be possible to bend one of those to your proposed usage, it's far from ideal, for a number of reasons: It's far more expensive than the single P-FET that you need to get the job done It's risky: you can easily reverse the current through your components and blow them up It imposes a ground offset which can cause you communication problems. All ...


3

Expanding on my previous comment... I need a way to keep an array of memory ignored by the C initializer You can achieve this by instructing the compiler to store the array in the “.noinit” memory section: int my_array[ARRAY_LENGTH] __attribute__((section(".noinit"))); Your array will end up sitting somewhere between the .bss and the heap (if any), and ...


3

You have an N-channel MOSFET. That is not suitable for switching the 12V supply of an Arduino. Instead you need a P-channel MOSFET which has the gate pulled up to 12V using a resistor, and then an N-channel logic level MOSFET which is used by the Arduino to pull the gate of the P-channel MOSFET LOW to turn it on. Something like: simulate this circuit &...


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 ...


3

You are wasting a lot of power in your system. You need to be far more efficient when running off battery. Don't boost your battery voltage to 5V. Instead use a system that runs entirely at 3.3V. Never use a linear voltage regulator like the AMS1117 since it just wastes power as heat. Instead use a switching "buck" regulator. Turning off modules when not ...


3

The TIP120 is possibly the worst transistor you could choose for this job. It is a Darlington Pair transistor, and those have a (relatively) massive forward drop of between 2 and 4 volts. It works with the LED because an LED needs a tiny amount of current to operate compared to the motor and has a fixed forward voltage of its own. The motor doesn't, and is ...


3

So you want to use the 5V voltage regulator on the Arduino serve as the supply for your 5V components, and feed the 5V regulator from the 12V supply that powers your solenoid? The problem with that plan is heat. The voltage regulator on the Arduino is a poorly heat-sinked (heat-sunk?) "linear" regulator. A linear voltage regulator is basically a solid state ...


2

Hold the reset button while you start the upload. Wait until you upload first tries to connect to the Arduino, then release the reset. If you can't get that to work, the next option is to load another Arduino with the ArduinoISP example sketch, connect the two as described in the comments, and use the 2nd Arduino to program yours. Update: Would ...


2

The Arduino Uno has no on-board battery. The dc barrel jack is provided to give you more options to power the Uno, which is handy for stand-alone applications (without USB-connection to a computer) and/or battery powered applications. It can also supply more current than the USB-connection, which can be necessary when using shields. The current taken from ...


2

OK. Looks much better now. And I see one problem. It seems that the normal way to do the speed control is with a pot. A variable voltage at the input depending on the rotation. The Arduino low end designs have an analog out capability but it really is not analog. It is a pulse width variable signal that produces an on percentage between 0 volts and the CPU ...


2

Welcome to arduino.stackexchange. You can program your ATmega32U4 on at least two ways: 1. Use Arduino's bootloader and D+/D- pins. This way you won't need an external programmer. Try search for phase "programming ATmega32U4 with bootloader". 2. Use ISP (In-System-Programming) method. In this case you can use your avr programmer. To do so you also need ...


2

It sounds like there's some form of short, or the AM1117 regulator is dead. Too much current being drawn by the regulator (as it gets so hot) has caused the diode to blow. You will need to replace both the regulator and the diode and hope it works - or use a separate external regulator into the 5V pin instead. Personally, I'd use a switch-mode regulator (...


2

The ESP8266 will do an analog calibration when it is running the user code. This will typically be the worst case power requirement. The peak current requirement can be as much as 1/2 an amp. While your regulator probably can supply that I would bet your interconnecting wiring, and maybe the power source, are causing too much voltage drop. The fact that ...


2

Easy Very Low Power BLE in Arduino covers using Arduino IDE and nRF52832 chips to code very low power projects, i.e. <100uA continuously, waiting for connection or while connected and sending data. The <100uA current is at max tx power and can be further reduced by reducing Tx power and increasing the advertising and connection intervals. Ignoring ...


2

Many (most?) household doorbell systems in the US are powered by a simple transformer that converts 120V AC household electric supply to a lower voltage AC. Often 16V AC or 24V AC. The coil and hammer form a device called a solenoid. When the coil is energized, the hammer (often also called a plunger) is forced in one direction, either up (against gravity) ...


2

The Arduno UNO SMD R2 uses an MCP33269 not an LM1117. What you have is probably some cheap Chinese clone of the Arduino, and in that case the regulator will be the cheapest Chinese copy of the LM1117 available. It's impossible to tell what the specs of that specific chip are. Suffice it to say, though, that the specs of the chip are pretty much irrelevant ...


2

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 ...


2

The robojax microphone switch I was using outputs LOW when it senses a sound rather than outputting HIGH as I assumed. The solution was just to replace all the if statements testing for a HIGH input with LOW. note: sorry about not looking into the microphone earlier.


2

There's a number of things to consider when choosing batteries. First is the capacity. In broad terms, the capacity is, mAh, means "This battery can supply X mA for one hour". So a battery of 1000mAh could supply around 1A (1000mA) for one hour before it goes flat. Simply divide the mAh by your device's mA and you get the time it will run for before it ...


2

The input current does not depend on the pin level. Have a look at this discussion from avrfreaks. The input impedance of a digital pin is extremely high. The leakage current of the Atmega328P (here as example chip) is mentioned to be 1uA for both pin states. So this current is both unavoidable and neglectable from a normal view. But the input impedance of ...


2

I realize that power is flowing the entire time the switch is open, which may (or may not) drain the battery. No, it doesn't. You get a small spike as the switch is opened or closed, as the gate capacitance is charged or discharged, but other than that there is negligible current draw by a pin, which remains static regardless of the direction of the biasing ...


2

If the sensor does provide two defined voltage levels, you do not need a pullup or pulldown resistor, but if it's only a switch: either (closed) connected to Vcc or GND, or (open) not connected, you need a pullup or pulldown resistor to get a defined voltage level in case there's "nothing else" (except the wire to the switch catching noise out of the air) ...


1

No. You have everything wrong there. First off, a power supply does not provide power. It provides voltage. The device attached to it then draws current. As much current as it needs at any particular moment in time. The current rating of a power supply is the maximum that the power supply can give. The same goes for Arduino IO and power pins: The current ...


1

There is no 5 or 10 second sleep. You can't just arbitrarily choose how long to sleep for. The watchdog timer only has specific periods (defined by dividing the clock by a set amount) that it can sleep for: enum period_t { SLEEP_15MS, SLEEP_30MS, SLEEP_60MS, SLEEP_120MS, SLEEP_250MS, SLEEP_500MS, SLEEP_1S, SLEEP_2S, ...


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