ADS1115 with NUCLEO-F401RE

Wiring for the ADS1115 16-bit ADC on the NUCLEO-F401RE (STM32F401RE, 3.3 V logic), chosen with the same pin rules BoardPilot uses: default buses first, and no pins that are used for flash, USB, the debugger or booting.

Wiring

ADS1115 pin	Role	NUCLEO-F401RE pin	Notes
VDD	Power	3V3
GND	Ground	GND
SCL	I2C clock (SCL)	SCL/D15 (PB8)
SDA	I2C data (SDA)	SDA/D14 (PB9)
ADDR	Not wired to the board	not connected	Address select: GND 0x48, VDD 0x49, SDA 0x4A, SCL 0x4B
ALRT	Interrupt	D2 (PA10)	Alert / ready output, optional
A0	Not wired to the board	not connected	Analog input. Never above VDD
A1	Not wired to the board	not connected	Analog input
A2	Not wired to the board	not connected	Analog input
A3	Not wired to the board	not connected	Analog input

Check before you power it on

Supply: 3.3 V from the 3V3 pin.
I2C uses the board’s default pins SDA/D14 (SDA) and SCL/D15 (SCL). Most modules include pull-up resistors; if the part is not found, check them and swap-test SDA/SCL.

Test code (Arduino)

#include <Wire.h>

void setup() {
  Serial.begin(115200);
  Wire.begin();  // SDA = SDA/D14, SCL = SCL/D15 (the board's default I2C pins)
  Wire.beginTransmission(0x48);
  bool found = Wire.endTransmission() == 0;
  Serial.println(found ? "ADS1115 16-bit ADC found at 0x48" : "Not found: check power, GND and SDA/SCL");
}

void loop() {}

Arduino board: STMicroelectronics:stm32:Nucleo_64:pnum=NUCLEO_F401RE. Plug the USB cable into the mini-USB port on the ST-LINK end. No button press is needed.

Questions

Which NUCLEO-F401RE pins do I use for the ADS1115?

VDD → 3V3, GND → GND, SCL → SCL/D15 (PB8), SDA → SDA/D14 (PB9), ALRT → D2 (PA10).

Does the ADS1115 work with the NUCLEO-F401RE at 3.3 V?

Yes: the ADS1115 runs at 3.3-5 V and the NUCLEO-F401RE uses 3.3 V signals, so no level shifting is needed.

What is the I2C address of the ADS1115?

0x48 or 0x49 or 0x4A or 0x4B. An I2C scan (BoardPilot does it for you) shows which one your module uses.

BoardPilot checks this wiring in 3D as you build it, and finds crossed or missing wires on the real board.

Download BoardPilot

Full NUCLEO-F401RE pinout · ADS1115 16-bit ADC: all pins and data

The ADS1115 on other boards

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