Hi, i'm working on a project for my car which currently have the following features(+modules):
0)Mini DC-DC Buck Converter (ajustable)
1)lock/unlock the car if my phone or family phone is in the area
(Here i used a HC-05 module only on command mode which always check if our phone is connected or not, the HC-05 module is attached to a npn transistor so i can switch it on/off from my arduino) + (a diy module to read if the car is locked and to interact with the central locking to change it)
2)1602 LCD (via i2c) with multiple informations/settings like (car battery voltage/temperature/features status)
3)x1 i/o pins expander (mcp23S17) for buttons/potentiometer which are use to navigate the lcd menu)
4)Interior light (just controlling a RGB led strip with mosfets)
5)Car alarm (using a vibration module + diy module with a relay for the alarm horn)
6)Long code (1300 lines) not very optimized but working (still have to solve little problems)
7)Arduino Nano (328p)
Here comes my question :
Because i want to attach it to my car (with a normal off battery drain of 15mA) i need to make it as low power as it can and this is a big problem because my current consumation is 68mA
First i tried to:
- lower the voltage to 3.6V
- remove leds from my Arduino NANO
- remove leds from the LCD (actualy from the i2c convertor)
and the drain is now 36mA (still a lot from a decent consumation that won't affect my car battery
and beside that i even have a problem with my LCD ( the text have no more contract even if try to ajust it via the pot)
I'm also thinking at the following:
-removing the leds from the bluetooth module
-add a npn transistor for the LCD too and istead using lcd.nobacklight() as a idle timeout solution completly shut it down
-reducting the voltage to 3.1V
-tring to implement sleep into my code(but i'm still a very beginner so i'll start with the simple ones)
-still need to fix the lcd problem and i think i just need to replace a resistor for the background led (need to research)
I want to know your solution
*if anyone wants to have a look on my code here it is:
// Car alarm project G3orG3 @2016/* TO ADD: -MORE PINS -RGB LED - Pastebin.com (as i said i'm a beginner and this is my first medium-big project)*