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11

can I charge the battery while the arduino is still on, but on power savig mode? You can draw power from a Li-Ion battery whilst charging it, but it isn't recommended. This is because the load on the battery affects the ability to detect the different phases of charging, and determine the end-of-charge condition. Instead you should provide a bypass ...


7

I'm not surprised you can smell burning. You have the power supply connected backwards. You see that little + and - symbol next to the ON/OFF jumper? That's the polarity of the two runs of pins. You have the + row connected to the - rail of your breadboard (blue) and the - row connected to the (red) positive rail. Turn the power supply around 180° and ...


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

The thing to remember with power banks bought on places like eBay and Amazon is: THEY LIE ABOUT THE CAPACITY A typical power bank you would expect to get around 3600mAh from, even though it may say 10000mAh, 50000mAh, 1,000,000,000,000mAh, etc. The only technical difference between rolling your own circuit and a power bank is the low-current switch-off ...


2

I'd recommend using the Arduino Leonardo as a reference for your circuit. Its pretty much the same as an Arduino UNO but has a built in USB interface so you don't need the USB-Serial converter. I'd also recommend running the chip at 3.3V. That way you can use a linear regulator to regulate the 3.7V battery voltage down. Otherwise you'd need a boost ...


2

Use a TP4056 1A LiPo charger board (it has overdischarge protection) and a boost converter, like the XL6009. It will run you at most 5$ if you are prudent. Overdischarge protection is important. If you want a port for programming, add a micro-USB breakout board, and if necessary a pushbutton for bringing RST down to GND. I prefer just having GND, TX, RX ...


2

Probably the easiest/cheapest and safest option is to buy a original USB Power Bank and there you have it. Power banks for cellphones/tablets have overvoltage/overcharge/undercharge protection on them and they are also completely sealed, so it should be perfectly safe to handle one of those to your kids (Of couse not some cheap chinese crap). They can then ...


2

Application Note AN1149 by Microchip Inc: It is NOT encouraged to attach the system load directly to Li-Ion batteries when using a stand-alone Li-Ion battery charge management controller with automatic termination feature. Why not? 1. The charge may never end. Most Li-Ion battery chargers are based on Constant Current and Constant Voltage ...


2

Another problem you can run into is that a lot of the A/D converters use the VCC as a voltage reference. Which means that as your input voltage drops (what you are trying to measure) the reference voltage also drops which means the values you are recording will not appear to change or at least will not give an accurate reference.


1

The TP4056 is a battery charger, not a voltage regulator. It cannot be used to supply power to a device like an Arduino. It is designed for charging the Lithium Ion battery from a 5V (e.g., USB) source. By trying to use it as a power supply you're asking for trouble. It thinks it's trying to charge a battery (from a 3.7V nominal source) and will be doing ...


1

You can read the Arduino's supply voltage see here How to measure the supply voltage of Arduino without using an analog pin Alternatively use the internal 1.1V reference and a suitable voltage divider to read the lipo's voltage


1

This is exactly why the typical LiPO battery shield includes a boost converter. I'm not sure where you saw the unusually high (3.5V) low-voltage limit, but that isn't typical of most converters.


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

Powering all the ESCs from a single LIPO is not an issue. Using a breadboard to distribute this power is highly unlikely to work, breadboard connectors are usually only good to a few hundred mA, 1A is you want to push your luck. Most ESCs and BLDC motors are in the 5A to 50A range (each, your power bus has to handle 4 times this current). Also, ESCs ...


1

No, you can't. The charger circuit will only operate properly with a battery attached. It is not designed to provide power to a system. It is designed for charging the battery and nothing else. You are supposed to remove the battery from the charger and then attach it to your circuit. Even with a battery attached you can't use it to power your circuit - ...


1

If you need to charge it and rum at the same time, I would recommend getting a Poweboost module from Adafruit. They can handle both, and they also have a low battery indicator.


1

Following on from Sean Watson's answer, I would probably use the Bare Conductive Touch Board as your reference. It's a Leonardo derivative with all the features you're asking for. Full disclosure - I work at Bare Conductive and worked on the design of the board. Eagle schematic and board file are here. Also, since this board successfully passed CE and FCC ...


1

Adding a 100ms delay before calling oled.init(0x3c); oled.clear(); oled.startScreen(); made this problem go away.


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