![arduino battery monitor arduino battery monitor](https://i1.wp.com/www.the-diy-life.com/wp-content/uploads/2016/11/Screenshot-2019-05-14-at-18.17.22.png)
The Arduino ADC returns a 10-bit value from 0-1023 based on an input voltage of 0V-5V.
![arduino battery monitor arduino battery monitor](https://www.twovolt.com/wp-content/uploads/2020/06/Arduino-Battery-Level-Monitor-Using-15-LEDs-5.jpg)
Normally the battery/charge voltages range from 12V-14V.
![arduino battery monitor arduino battery monitor](https://i.ytimg.com/vi/vJbWlFkIuXc/maxresdefault.jpg)
The 10V Zener diode drops 10V leaving a voltage value of 0v-5V at TP1. The battery voltage is measured from the TP1. The 5V regulator is build into the unit I used and if not use a separate 5V supply.
#ARDUINO BATTERY MONITOR CODE#
One can easily add the ideas from that project to this one.Ībove is a generic Arduino Nano, but the code will work on any Arduino style microcontroller. This is a simplified version of my Solar Panel Battery Charge Controller Using Arduino. Which as we know is 1.1 volts.Solar Panel Battery Charge Controller Switching Circuit
#ARDUINO BATTERY MONITOR SERIES#
Many AVR chips including the ATmega series and many ATtiny series provide a means to measure the internal voltage reference. In some cases it can be completely unreliable! How-To The choice of the internal reference is inexpensive and stable, but most of the time, we would like to measure a broader range, so the Vcc reference is the most practical, but potentially the least accurate.
![arduino battery monitor arduino battery monitor](https://cdn.instructables.com/ORIG/FPL/0ROQ/J2AVZBLE/FPL0ROQJ2AVZBLE.jpg)
Vcc is completely untrustworthy in most cases. The internal reference is stable, but has about a +/- 10% error. An external voltage reference is the most accurate, but requires extra hardware. Most AVR chips provide three possible sources – an internal 1.1 volt source (some have a 2.56 internal voltage source), an external reference source or Vcc. In order to measure analog voltage accurately, we need an accurate voltage reference. Here is example code illustrating the problem: double Vcc = 5.0 // not necessarily trueĭouble volt = (value / 1023.0) * Vcc // only correct if Vcc = 5.0 volts If our power supply is not perfectly regulated or if we are running on battery power, this voltage can vary quite a bit. The fact is the default analog reference is not 5.0 volts, but whatever the current level of Vcc is being supplied to the chip. The official Arduino documentation even leads us to this wrong assumption. Why?Ī common assumption when using analogRead() is that the analog reference voltage is 5.0 volts, when in reality it may be quite different. Also, when battery powered, Vcc is not going to be 5.0 volts, so if we wish to make analog measurements we need to either use the internal voltage reference of 1.1 volts, or an external voltage reference. One is if our project is battery powered, we may want to monitor that voltage to measure battery levels. There are at least two reasons to measure the voltage supplied to our Arduino (Vcc). In this article, I have incorporated some additional improvements. I first learned of this technique from these articles – Making accurate ADC readings on the Arduino, and Secret Voltmeter. It can also be used to measure the Vcc supplied to the AVR chip, which provides a means of monitoring battery voltage without using a precious analog pin to do so. This feature can be exploited to improve the accuracy of the Arduino function – analogRead() when using the default analog reference. A little known feature of Arduinos and many other AVR chips is the ability to measure the internal 1.1 volt reference.