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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

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 ...


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 ...


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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 ...


3

ATTINY's are designed to easily do this since they can wake from power down sleep mode by a pin change... Basically you want to... Connect a normally-open push button between an IO pin and ground. Enable the pull-up on the IO. Enable the pin change interrupt on the IO pin. Enable interrupts. Enter "power down" sleep mode. When the button is pushed, it ...


3

Look at the datasheet of the ATtiny45. In the section “Sleep Modes”, there is a table that lists the wake-up sources available for each sleep mode. For the mode “power-down”, INT0 is listed as a possible wake-up source, but there is a small footnote: For INT0, only level interrupt. This means that the CHANGE mode you are trying to use will not wake-up ...


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This looks like something out of an Arduino n-part “sensor kit”. It’s hard to tell because the quality of the image is not very good. My guess is, this is an analog temperature sensor, like in this link, part number 18. You can also find an example sketch there.


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As mentioned in the comments, you cannot power your robot from a 9V block battery. These are made for low power projects (like a smoke detector) and cannot provide enough current to drive even only the motors correctly. Using 2 of them does not really help much. You need to change to a different battery type. If you want to stay with alkalines, you could use ...


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 ...


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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.


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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

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) ...


2

Two of those 10mA come from the ATECC608 crypto chip which idles at 2mA. That leaves 8mA for you to track down. The WiFi-NINA module has multiple "sleep" modes that range from 30mA down to 4.5µA. Since you can't be in the 30mA "modem sleep" mode (it's too high for your measurements) I suspect it enables "light sleep" at 800µA. The switching regulator ...


2

You set the variable data only in the setup function. You also do not print out data to Serial but the output of rtc.toString(buffer). If data is not updated in the loop method, the display constantly shows the time you initially set in the setup method.


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Your strip has 2 LEDs with different color temperature directly besides at the same spot for every element of the strip. So the adjusting of the overall color temperature is done by changing the relative brightness of both LEDs. If the LED with the warmer light is brighter, the overall color temperature will also be warmer. Common Anode means, that V+ is the ...


2

AFAIK, Arduinos are set up to use their operating voltage as the analogRead reference voltage by default. So, what I think is happening is that you are trying to measure the battery voltage with the battery itself as a reference voltage. This will, of course, always show "full scale". You could use a voltage divider to bring the measured battery voltage ...


2

3 different ways to power the Mega2560 besides connecting to a PC: 7.5V to 12V 'wallwart' supplying DC to the barrel jack. 5V wallwart connected to the USB port. 5V wallwart connected to the 5V/Gnd pins on the Power header.


2

Does the MB-102 can handle Arduino Uno, SIM900 and 3 other modules that requires 5v? You mean because the current requirements? The answer is yes and no. No, because the needed current must not flow through the Arduino. The SIM900 draws up to 2A, that current would fry the protection diode/voltage regulator on the Arduino (though you may get away with a bit ...


2

I've seen people saying something about putting the grounds of the board and the module together Yes, I believe this is what you need to do. Servo is connected by to pin 10, and the ground and power are both routed through the 5V power module which is attached to a 9V battery. From what I understand, you are wiring like this Servo 5V - 5V Power module ...


2

That is a perfectly legitimate use of the RESET pin. Holding the chip in reset perfectly valid. Everything in the chip will be stopped. Releasing it will start your sketch from the start again perfectly fine. The only negative point is that your switch will be pulling power through the reset pin's pullup resistor, so will waste a little power.


1

There is a chance that this arrangement could damage the servo and possibly the Arduino. The problem is that, depending on the internals of the servo, it could try and draw power for the servo through the data pin when the button is not pressed. This would both over-stress the internals of the servo and the internals of the Arduino's GPIO pin. What you ...


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FYI, this issue was brought up nearly 3 years ago, with no response from the author: https://github.com/rocketscream/Low-Power/issues/36


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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 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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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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