SparkFun Forums

[DarkStar]

Hello everybody this is my first post so hopefully this in the right section. Anyways i was searching through the SparkFun products for hours as usual and found a "10 Segment LED Bar Graph-Red" and thought it would be a really cool to make a battery life meter out of it, like every segment could be 10% battery life so a full battery would have all 10 segments lit and a dead battery would have no segments lit. Does anybody know if this could work? and if so how would i get started doing this. Thanks


Here's the link: http://www.sparkfun.com/commerce/produc ... ts_id=9935


p.s.-Thanks SparkFun for some awesome products!!

[itikhonov]

20mA * 10 leds = 200mA. Your bar will suck 80% of 2000 mAH battery in 14 hours. And it's not counting you need to get 2.1V and switch LEDs according to battery voltage somehow

[DarkStar]

Thanks I didn't think of the power consumption but now I'm thinking I could just hook it up to a button so when I want to check the battery life I just hold down a button, that should work right? Also if the button idea will work I still need to figure out how to get the leds to show the battery life, does anybody know how this could work?

[trialex]

I'd start by looking at the bar graph drivers like LM3914/3915/3916

[DarkStar]

Thanks trialex!! that was exactly what i needed!! and I think i found a good diagram for a battery meter with the "bar graph driver LM3914" but the diagram in the link is for a 12v meter but i need 5v so i will have to figure out different resistors for my voltage any suggestions. Thanks for the help


http://www.electronicecircuits.com/elec ... r-circuit/