MKRFOX1200 read battery voltage

[astroman35]

Hi guys,

I saw on this page that it's possible to read battery voltage on the MKRZERO board with few lines of code :

Code: [Select]

  /*
  ReadBatteryVoltage
  Reads the analog input connected to the battery output on a MKRZero or MKR1000, converts it to voltage, and prints the result to the serial monitor.
  Graphical representation is available using serial plotter (Tools > Serial Plotter menu)

  This example code is in the public domain.
*/

// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 9600 bits per second:
  Serial.begin(9600);
}

// the loop routine runs over and over again forever:
void loop() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(ADC_BATTERY);
  // Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 4.3V):
  float voltage = sensorValue * (4.3 / 1023.0);
  // print out the value you read:
  Serial.print(voltage);
  Serial.println("V");
}

I tried to put this code in the MKRFOX1200 but the value returned are weird.
I've modified the formula by replacing 4.3 with 3.3 but same problem.

Do you know if it's possible to read battery voltage on this board ?

[ManfredDoetsch]

This one works:



// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 9600 bits per second:
  Serial.begin(9600);
}

// the loop routine runs over and over again forever:
void loop() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(A0);
  // Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 5V):
  float voltage = sensorValue * (5 / 1023.0);
  // print out the value you read:
  Serial.print(voltage);
}


Did you check the constant ADC_BATTERY ?

[astroman35]

Thanks for your answer ManfredDoetsch, i will check it in my next code upload.

[astroman35]

Hi,

I've uploaded ManfredDoetsch code in my board but it doesn't seem to work as expected.
Here is a historical view of the voltage value since may 25 :

Do you have any idea ?

[fabricecarrique]

Have you advance on the function to read the battery life, I have a similar project.

[flc85]

For the mkrfox1200 maximun input 3.3v

Warning: Unlike most Arduino & Genuino boards, the MKRFOX1200 runs at 3.3V. The maximum voltage that the I/O pins can tolerate is 3.3V. Applying voltages higher than 3.3V to any I/O pin could damage the board. While output to 5V digital devices is possible, bidirectional communication with 5V devices needs proper level shifting.

[GeirFrimann]

Anyone got a solution to reliably read the battery voltage on a MKRFOX1200?
It is a must-have feature for my project.

[janvanbogaert]

In order to have an accurate battery measurement you need to compare the battery voltage to a reference voltage.
The MKRFOX1200 has an internal reference voltage of 1V.
The  ADC_Battery pin is connected to a resistor network that divides the battery voltage. So in case the battery voltage is 3.3V, the voltage at battery equals 1V. You need to tell the ADC to compare the ADC_Battery with the internal reference voltage of 1V. I believe this can be done using the analogReference() instruction.

[jpe1908]

I have a project, where I also have to read the battery level, and I use the analogReference(), and it works fine....but I also have to use another analog pin to measure a distance, but that don't work when I use the analogReference().
What to do ?

[jot4p]

Based on this thread.

Code: [Select]

 
void loop() {

  analogReadResolution(10);
  analogReference(AR_INTERNAL1V0); //AR_DEFAULT: the default analog reference of 3.3V // AR_INTERNAL1V0: a built-in 1.0V reference
 
  // read the input on analog pin 0:
  int sensorValue = analogRead(ADC_BATTERY);
  // Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 4.3V):
  float voltage = sensorValue * (3.25 / 1023.0);
  // print out the value you read:
  Serial.print(voltage);
  Serial.println("V");

}


Result: 3.25 volts for 3.25 volts battery

[martinsokolik]

Hi,
this code isn´t functioning for me.
Code resault is 4.3V and battery has exactly 3.51V
Whats is wrong?

I have MKRFOX1200 + 3.7V LiPo battery

[pacxxi]

Hi, I tried the code pasted above but didn't work for me.

I started measuring differents batteries,  and I founded that  analogRead(ADC_BATTERY) instruction give directly the voltage *100, I don't know the reason.

Due the measurement error (arduino or multimeter), I made an average and my correction factor is 103.06.

You don't need to change the analog resolution or the analog reference, all these values are by default.

I paste my code

in void loop

// read the battery:
  int battread = analogRead(ADC_BATTERY);
// convert to a voltage:
  float voltbatt = (battread / 103.06);