#Arduino battery monitor how to

Voltage Reference – The converter is only as precise as the reference voltage applied to it. The more boots, the more granular the output can be. Number of Bits – This determines how many “steps” the converter can divide the input into. The accuracy of this conversion is determined by a few different factors: It’s a component that accepts an analog input and produces a digital output, the output being a digital representation of the level of the input. Analog to Digital ConvertersĪn Analog to Digital Converter is pretty well exactly what it sounds like. Many modern microcontrollers, including the Arduino Uno, have a built-in ADC, making DC voltage measurement the simplest of our four tasks. Measuring DC Voltage with a microcontroller (or any digital data device) requires the use of an Analog to Digital Converter (ADC). The techniques here apply to any microcontroller, in fact devices like the ESP-32 or Seeeduino XIAO can actually perform better DC voltage measurements as they have analog to digital converters with a higher resolution.

#Arduino battery monitor how to

Then, in the Arduino sketch, I'll start by including the library and initializing the sensor: # include 'MAX17043.In this article, I will show you how to measure DC voltage and current using an Arduino. I'll start by adding it as a dependency to my platformio.ini file: lib_deps = There are several Arduino libraries for the MAX17042:īoth of these will work fine, even with breakout boards from different brands. Now that everything is wired up, we can start writing some code. That's why there are 2 additional wires in my setup. It only accepts power over USB or the battery connector. However, in this case, my ESP32 board can't be powered through its pins. The fuel gauge will pass along power to the microcontroller. Note: Normally, you only have to connect the battery to the fuel gauge, and the fuel gauge to your microcontroller. I'm using a 2000mAh LiPo battery and a LOLIN32 board (ESP32 based), but you can use any microcontroller you'd like, including an Arduino. Here's a simplified schematic that should work regardless of the breakout board you have: Wiring it upĬonnecting this breakout board to your microcontroller is easy: connect the power output to the VIN of your board and connect the SDA and SCL pins for i2c connectivity. Other brands have similar boards: SparkFun / AliExpress.

It also has an interrupt pin, so you can have it wake your microcontroller when the battery dips below a certain level.Īnd even more good news: it's available as a breakout board for DIY projects, such as this one from DFRobot:

It works through an i2c interface, and it can report the battery's percentage and voltage. It doesn't require resistors or calibration. This tiny chip uses the ModelGauge algorithm to measure a battery's capacity. Fuel Gauge: MAX17043Ī better solution is to use a 'battery fuel gauge,' such as the Maxim Integrated MAX17043 ( datasheet). It's challenging to convert a measured voltage into a battery percentage. The voltage drops off quickly in the beginning, stays very stable for a long time, and then suddenly drops low at the end of its life: And secondly, the voltage of Li-ion or LiPo batteries doesn't drop linearly. First up: it continuously drains the battery (depending on the resistors you use). Usually with a voltage divider to bring down the voltage so that an ADC can read it.īut this method is not ideal. Many websites tell you to measure the battery level by measuring its voltage.