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5

You need a voltage divider with resistors that have large values. ...but with all values I have tried one resistor almost melts as soon as you connect to battery. This suggests that you have been using values that are too low. So lets go through the calculations to select good resistor values. 1/4 Watt resistors are common and easily available so I ...


4

As @dandavis rightly says in the comments, you can't measure the battery voltage from a power bank. This is because the power bank typically includes a step-up converter to turn the batter voltage (3.2 to 4V) into a stable 5V. That 5V will alwaye be 5V (or thereabouts) until the battery runs out and the power bank shuts itself off. To measure the battery ...


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

It sounds as if you have tried using far too small a value resistors. For example, if you used resistors totaling , say, 1,000 ohms across a 50V supply then they would dissipate V^2/R watts = 2.5W. Standard 1/4 watt resistors are going to melt when overloaded 10 times. So it boils down to picking a pair of resistors that 1) Are working within their wattage ...


2

You can either use the 3.3V pin to supply power to the board, or use the Vin pin. By using the VIN pin to power goes through a (step down) voltage regulator, that provides a nice stable 3.3V to the board. The regulator in the Nano 33 IoT is the MPM3610, which requires an input voltage of at least 4 - 4.5 Volt. Which is more that a LiPo or LiFePo single cell ...


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

From the very page you linked to: "... we added a connector for any of our 3.7V Lithium polymer batteries and built in battery charging. You don't need a battery, it will run just fine straight from the micro USB connector. But, if you do have a battery, you can take it on the go, then plug in the USB to recharge. The Feather will automatically switch over ...


2

You have far too many variables and unknowns there. Primarily you need to know what the average current draw for your circuit is. Secondly you need to decide how long the solar powers are allowed to take to recharge the battery. You have to think not only about runtime but also charge time. The charge time dictates the maximum capacity of the battery, and ...


2

You can't run the fan directly from an Arduino pin. The fan will require to much current for that to work. Instead connect the fan, via a transistor/mosfet to the Arduino. Also add a (flyback-)diode to the fan, as turning of the fan can create huge (but short) voltage spikes, which can damage the transistor/mosfet. Pseudo code would be something like: ...


1

The VIN (and the USB) goes into a 3.3V switching regulator. This has a minimum input voltage of 4.5V. You isolate the output of that regulator from the rest of the circuit by cutting that one link (which is easy to re-solder). You are then free to feed 3.3V from your own power source directly into the board. Yes, if you provide more than 3.3V you are ...


1

The output voltage of the charger board is marked with BAT. You should connect it to the Vin pin of the Teensy, which then will convert the batteries 3.7-4.2V down to 3.3V. Of course you need to connect the grounds of the charger board and the Teensy (on the charger board ground is marked with G). The 5V pin on the charger board is no output. The board ...


1

Actually it is two separate questions and I answer your first question of reading multiple analog values using one ADC and the answer is Yes you can use this approach but you should give enough time for each channel to charge internal ADC capacitor when you change channel .so if you use more independent ADC you get more time for each channel and result is ...


1

is it safe to wire the boost converter directly to the output terminals of the battery/batteries and take the 5V off the +5v pin using a common ground? Yes. That is the normal way of using them. Also, I'm not 100% sure how to go about charging this setup. One option would be to put the batteries in cases and use an external charger with replaceable cells....


1

You have 3 problems here: Driver circuit the motor: Since you only want to control the motors speed (not changing it's direction, where you would need a H-bridge like the L298N), a very simply driver circuit is sufficient. It can consist of a bipolar transistor or a MOSFET. The Arduino's digital output pin would set the transistor/MOSFET to conductive or ...


1

The Arduino Micro requires 5V. It runs at 16MHz, and you can't run at 16MHz at voltages below about 4V. To run off a 3.7V battery you need an Arduino board that runs at 8Mhz, such as the "3.3V Pro Micro" from Sparkfun. To know if your battery is suitable for your project you need to work out the hourly average current draw. That is the proportion of "...


1

Answering the second question "Also I would like to display the battery level...?" (next time, please open a new question for that): To measure the module voltage level (a.k.a. VCC) of a NodeMCU (which is just a board containing an ESP8266 chip) programmed in Arduino IDE (which I assume given that you ask on the arduino stackexchange), this here applies: ...


1

It is still usable for higher capacities. I recommend you tp4056 and some step up converter. You can use resistor divider (that drops safely voltage to nodemcu 3.3v) and connect its output to an analog pin of your nodemcu. Values of resistors must be high, like 10k. You can simply connect your diode to nodemcu and code if voltage is less than 3.2v let the ...


1

The input voltage on the DC pin is specified as 7 to 12V. Your battery may well be supplying more than that, causing the voltage regulator to overheat and shut down. The voltage was 12.62 volts. That is out of spec for the Arduino Uno. When you operate out of specified voltages anything can happen, and that anything may not be very good. You could get a ...


1

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 ...


1

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.


1

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


1

You have a LiPo charger module. It's meant to charge single LiPo cells. It is therefore, the intended safe use that you can connect any single LiPo cell to it. All single cell LiPo batteries are nominally 3.7V. The only real question might be -- does the charging circuit try to charge too fast? A 2000mAh pouch LiPo can safely be charged at 1X the capacity. ...


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