ADS_1115 sampling rate

[ptc]

Hi,

I am trying to use the ads1115 adc to collect data from three inputs. I am using the ads1x15 library for Arduino. Using the example code, I get ~38 SPS. How do I increase the sampling rate?

thanks,

[adafruit_support_mike]

You'll want to use the function ADS1115::setRate(). Send it one of the following values from the header file:

Code: Select all

#define ADS1115_RATE_8              0x00
#define ADS1115_RATE_16             0x01
#define ADS1115_RATE_32             0x02
#define ADS1115_RATE_64             0x03
#define ADS1115_RATE_128            0x04 // default
#define ADS1115_RATE_250            0x05
#define ADS1115_RATE_475            0x06
#define ADS1115_RATE_860            0x07


[ptc]

Thank you for the quite reply.
However, I did not see this function in the ADS1X15 library that I downloaded from https://github.com/adafruit/Adafruit_ADS1X15. Is there a newer version?

[adafruit_support_bill]

Can you post the sketch you are using?

[ptc]

Code: Select all

#include <Wire.h>
#include <Adafruit_ADS1015.h>

Adafruit_ADS1115 ads1115;

void setup(void)
{
  Serial.begin(115200);
  Serial.println("Hello!");
 
  Serial.println("Getting single-ended readings from AIN0..3");
  Serial.println("ADC Range: +/- 6.144V (1 bit = 3mV)");
  ads1115.begin();
}

void loop(void)
{
  int16_t adc0, adc1, adc2, adc3;
    adc0 = ads1115.readADC_SingleEnded(0);
    adc1 = ads1115.readADC_SingleEnded(1);
    adc2 = ads1115.readADC_SingleEnded(2);
    Serial.print(millis());
    Serial.print(",");
    Serial.print(adc0);
    Serial.print(",");
    Serial.print(adc1);
    Serial.print(",");
    Serial.print(adc2);
    Serial.println(",");
}


[adafruit_support_bill]

You have about 18mS worth of serial printing in your loop. That will slow things down a bit.

[retrolefty]

You have about 18mS worth of serial printing in your loop. That will slow things down a bit.

Even with the fully buffered interrupt driven serial transmission that the arduino hardware serial now has?

Lefty