LED backlights typically take between 40mA and 120mA. The Arduino itself takes around 50mA.
So I am wondering, if I do not use the backlight, would I be able to extend the battery life significantly? If so, by how much?
Most 20x4 LCDs are I2C ....
In the one I have it is at the en
Yes, and a lot. There may be no need to get smarty farty about controlling the backlight. Most 20x4 LCDs are I2C and it is common to have a jumper on the adapter which removes power from the backlight. In the one I have it is at the end of the board and is labelled LED . It has nothing to do with the LED that is immediately adjacent. In normal room light, the display is fine with no back-light at all.
Guys, I have measured my LCD current drawn( only at the Vcc pin). And it is ard 1mA.. Is this in the normal range? And when I measured the backlight alone, it is ard 6mA.. Normal?
QuoteGuys, I have measured my LCD current drawn( only at the Vcc pin). And it is ard 1mA.. Is this in the normal range? And when I measured the backlight alone, it is ard 6mA.. Normal? You really haven't provided us with enough information to give you a definitive answer. All we can do at this point is make some guesses based upon some assumptions.Without a datasheet for your specific LCD module it is hard to tell if your values are normal but as far as the LCD current of 1 mA is concerned that seems possible. Without knowing how your backlight is powered and what type of meter you are using we really can't evaluate your 6 mA reading except to speculate on why it is so low. Nick could be on the right track with the observation that the 6 mA reading "may reflect the characteristics of the meter more than the power consumed" (when you substitute the term 'current' for 'power'). This isn't much of a problem when measuring non pulsating DC or pure sinusoidal AC but can be a big problem when measuring anything else.Also - many of the forum members do not have English as their native language and may therefore have problems with texting type abbreviations. I was able to figure out that you meant 'around' when you used the term 'ard' but others may not have done so. On the other hand I still haven't figured out what these sentences mean: "Nonetheless, it is a hell of a lot less than 120mA and any pulsed supply has to be good!" "They best way to go is probably to suck it and see by flattening the battery."Don
Is there something wrong in the way I measure the current using the multimeter?I connected the probes in series to the Vcc(the power pin) pin of the LCD display. And the other ends of the probes were connected to the ground and 300mA slots in the multimeter...