Getting Started with FoBE Breakout ADS1115

Introduction

The FoBE Breakout ADS1115 integrates the TI-ADS1115 16-bit ADC with programmable gain amplifier and the EEPROM for calibration data storage. The module provides multiple measurement capabilities including 0-10V voltage measurement, 4-20mA current measurement, and NTC temperature measurement with built-in 2.5V reference. Multiple connectivity options are provided for easy integration into various applications.

Applications

Portable instrumentation and measurement systems
Battery monitoring and power management
Temperature sensing and monitoring
Factory automation and process controls

Key Features

ADS1115
- 16-bit high resolution analog-to-digital conversion
- 4 single-ended inputs or 2 differential inputs
- Programmable data rate: 8 SPS to 860 SPS
- Internal programmable gain amplifier (PGA): up to x16
- Internal low-drift voltage reference and oscillator
- I²C interface with programmable address
- Interrupt/ready pin for conversion completion
M24C64 EEPROM
- 64Kbit (8KB) data storage capacity
- I²C interface with programmable address
- Calibration data storage capability
Built-in Reference
- 2.5V precision voltage reference
- NTC measurement and ADC calibration support
Connectivity
- MFP-IIC interface (JST-SH1.0 4-Pin)
- 6 x 2.54mm Pin Header
- 4 x 3.81mm Screw Terminal Block

Measure Channels

Channel	Measurement Type	Description
0	4-20mA current	Measured via 120Ω shunt resistor to ground
1	0-10V voltage	Measured through voltage divider (10kΩ/39kΩ)
2	NTC temperature	Measured via voltage divider with 100kΩ resistor and 2.5V reference
3	NTC Reference	Connected to internal 2.5V voltage reference

Hardware diagram

The following figure illustrates the FoBE Breakout ADS1115 hardware diagram.

Mechanical dimensions

FoBE Breakout ADS1115 is a single-sided 25.4mm x 25.4mm (1" x 1") 1.6mm thick PCB with two SH1.0 4-pin connectors and a set of 6-pin 2.54mm header holes. Fixing by 4 x 1.6mm Screw holes.

Interfaces

The module provides dual 6-Pin JST SH1.0 connectors, compatible with STEMMA QT / Qwiic.

2.54mm 6-Pin	JST-SH1.0	Features
NC	—	Not connected
GND	GND	Ground
3V3	3V3	Power supply, Only 3.3V
SDA	SDA	I2C-Data line
SCL	SCL	I2C-Clock line
INT	—	ADC conversion ready, Active Low

Advanced

Address Selection

ADS1115 I2C Address

The ADS1115 I²C address can be configured using solder pads B0-B3:

Pad	I²C Address
B0	0x48 (Default)
B1	0x49
B2	0x4A
B3	0x4B

EEPROM I2C Address

The M24C64 EEPROM I²C address can be configured using solder pads A0-A2:

A2	A1	A0	I²C Address
0	0	0	0x50 (Default)
0	0	1	0x51
0	1	0	0x52
0	1	1	0x53
1	0	0	0x54
1	0	1	0x55
1	1	0	0x56
1	1	1	0x57

Jumper

The module features one jumper pad:

Interface	Description
ADC-INT	Connect this jumper to enable INT pin functionality for ADC conversion ready signal

Measure Connections

Channel	Type	Configuration
0	4-20mA current	120Ω shunt resistor to ground
1	0-10V voltage	Voltage divider: 10kΩ (top) / 39kΩ (bottom)
2	NTC temperature	Voltage divider with 100kΩ resistor, 2.5V reference
3	Calibration	Internal 2.5V voltage reference

Programming

Running with FoBE Quill ESP32S3 Mesh

Let's get started with the FoBE Quill ESP32S3 Mesh using the MFP interface.

Connect the FoBE Breakout ADS1115 to the FoBE Quill ESP32S3 Mesh using the MFP interface.

Create a sketch or PlatformIO project, or follow the FoBE Quill ESP32S3 Programming Guide for pre-configuration.
Install the necessary library in your project:

adafruit/Adafruit ADS1X15@^2.5.0

Copy the following code into your sketch or PlatformIO project:

#include <Arduino.h>
#include <Wire.h>
#include <Adafruit_ADS1X15.h>

#define ADS1115_ADDR 0x48

#define IIC_SDA_PIN PIN_MFP3
#define IIC_SCL_PIN PIN_MFP4

Adafruit_ADS1115 ads;

void setup() {
  Serial.begin(115200); // Start serial communication at 9600 baud rate
  delay(3000);
  
  pinMode(PIN_PERI_EN, OUTPUT);
  digitalWrite(PIN_PERI_EN, HIGH);   // Enable peripheral power

  Wire.begin(IIC_SDA_PIN, IIC_SCL_PIN);  

  if (!ads.begin(ADS1115_ADDR)) {
      Serial.println("Failed to initialize ADS.");
      while (1);
  }
}

void loop() {
  int16_t adc0, adc1, adc2, adc3;
  float volts0, volts1, volts2, volts3;

  adc0 = ads.readADC_SingleEnded(0);
  adc1 = ads.readADC_SingleEnded(1);
  adc2 = ads.readADC_SingleEnded(2);
  adc3 = ads.readADC_SingleEnded(3);

  volts0 = ads.computeVolts(adc0);
  volts1 = ads.computeVolts(adc1);
  volts2 = ads.computeVolts(adc2);
  volts3 = ads.computeVolts(adc3);

  Serial.println("> FoBE Breakout - ADS1115");
  Serial.print("\033[H\033[J"); // Clear terminal
  Serial.printf("\033[7m%-12s%-12s%-12s%-12s%-12s\033[0m",
              "Channel", "Value", "Voltage", "Result", "-");
  Serial.println();
  Serial.print("\033[0m");
  
  Serial.printf("%-12s%-12d%-12.6f%-12s%-12.6f", "AIN0", adc0, volts0, "4-20ma:", volts0/120*1000);
  Serial.println();

  Serial.printf("%-12s%-12d%-12.6f%-12s%-12.6f", "AIN1", adc0, volts1, "0-10V:", volts1 * (100000.0f + 39000.0f) / 39000.0f);
  Serial.println();

  const double Rp = 100000.0;  // 分压电阻
  const double R0 = 10000.0;  // 10k NTC 
  const double T0 = 273.15 + 25.0; // 25℃
  const double Bx = 3950.0;
  const double Vref = 3.056250;     // 参考电压
  double Rt = volts2 / ((Vref - volts2) / Rp); 
  double tempK = 1.0 / ( (1.0/T0) + (1.0/Bx) * log10(Rt / R0) );
  double tempC = tempK - 273.15;
  Serial.printf("%-12s%-12d%-12.6f%-12s%-12.6f", "AIN2", adc2, volts2, "NTC(˚C):", tempC);
  Serial.println();

  Serial.printf("%-12s%-12d%-12.6f%-12s%-12.6f", "AIN3", adc3, volts3, "REF-3V", volts3);

  delay(1000);
}

important

This example code shows basic ADC channel reading. Your terminal must support the output format to display the measurements correctly.

# platformio.ini
[env:fobe_quill_esp32s3_mesh]
platform = FoBE Espressif 32
board = fobe_quill_esp32s3_mesh
framework = arduino
lib_deps =
	adafruit/Adafruit ADS1X15@^2.5.0
monitor_speed = 115200
monitor_raw = true

Build and upload the project. You should see the FoBE Breakout ADS1115 ADC channel data output in the serial monitor (raw mode).

Channel     Value       Voltage     Result      -           
AIN0        0           0.000000    4-20ma:     0.000000    
AIN1        0           0.002625    0-10V:      0.009356    
AIN2        1136        0.213000    NTC(˚C):   27.849865   
AIN3        16300       3.056250    REF-3V      3.056250      

note

If you want to use custom pins, you can change the IIC_SDA_PIN and IIC_SCL_PIN definitions to your desired GPIO pins.
The ADS1115 is configured to use the default I²C address 0x48. You can change the address by soldering the appropriate jumper pads on the board.

Resources

[PDF] FoBE Breakout ADS1115 Datasheet

[PDF] FoBE Breakout ADS1115 Schematic

[PDF] FoBE Breakout ADS1115 Dimension

[OBJ] FoBE Breakout ADS1115 3D Model

Introduction​

Applications​

Key Features​

Measure Channels​

Hardware diagram​

Mechanical dimensions​

Interfaces​

Advanced​

Address Selection​

ADS1115 I2C Address​

EEPROM I2C Address​

Jumper​

Measure Connections​

Programming​

Running with FoBE Quill ESP32S3 Mesh​

Resources​