I want to share my experiment with voltage divider, ADC and AVR
Homemade battery monitor using AVR
It's pretty simple the sensor are only two resistors and zener diode with capasitor, I don't buy them, I've found it in my box.
We can use it for monitoring our car battery voltage.
Step 1: The Part I Used
2.10K and 56K resistors as a voltage divider
3. 5V1 Zener diode
4. 1uF Caps,
5. 16x2 LCD
6. 3 wires to connect the sensor into ADC
Let's continue to the code
Step 2: The Code and Atmel Studio
you can calibrate first with 5V from 7805
This is the equation I used
adcA = ((int)((5000/1024)*adc_result));