or an arduino mega 2560 project i need alimentation of 7V minimum, i use two parallel lion batteries 3,7 V 2,6Ah each. i thought about finding a board online that charges these batteries but unfortunatly all deliver 4v output as max. I know that to better charge a battery the voltage have to be same or higher of the battery, which is not the case. i coudl buy a board and apply some changements but dont know reall what to do.. do u guys have some suggestions? thanks !
PS: Arduino takes current of 220 mA for a 5-9V alimentation.
The Arduino Mega 2560 runs on 5 volts. It depends on what else you will be powering from battery and for how long but you could use 1 piece 18650 and add a combo board like this.
It charges the battery and, in addition, it can supply electronics from the battery by increasing the voltage to 5 volts. You connect this 5 volts directly to the '5V' pin and not to the 'Vin' pin on Arduino board. In this way, it bypasses the linear stabilizer of the Arduino board. Be careful not to power the arduino board from USB and that way bcause you may have problems. Use only 1 power source.
it powers a tft touch screen, one potentiometer , two rgb and two 74HC4066.. i measured the total current consumtion and it was 202 mA. i was supplying the arduino with a generator through the plug and it didnt work until the voltage came up to 6,5V. You think this will make it work anyways?
These are all 5V or 3.3V components. None require 7V.
That is correct. The Mega's onboard regulator requires 6.5V input to make 5V output to power the Mega's other circuits. But if you supply 5V through the 5V pin, you can bypass the on-board regulator and power the Mega's other circuits directly.
the LCD needs 5v power supply which´s still not affordable with one battery, the batteries in series has to be done anyways.
i found some batteries like this one already packed together and protected with a pcm inside.
yes am certain, it´s the Kuman 3,5 tft touchscreen, not much to find about online other than it uses ili94869 as driver for displaying that needs 2,5 v and for touch XPT2046 that needs 1,5 v and i assume they are connected in series, that would require at least 4v which is already above the 3,3 v
Well, that's a nonsense assumption, and no basis for being certain.
The screen is designed for use with raspberry pi. It appears to connect to both the 3.3V pins and 5V pins of the pi. I can't find a schematic, so I have no idea why it needs to connect to both, unless it contains a 3.3V voltage regulator to avoid overloading the pi's regulators.
Do you know for certain it will work with Arduino?
This is what i found online, btw am using this library..
The Mcufriend shields are designed to work from 5V supply and use 3.3V reference for the logic .