Documentation

Overview

The XL4015 is a 5A high-efficiency synchronous buck converter that takes a wide DC input (4-38V) and steps it down to any adjustable output between 1.25V and 36V. With 96% peak efficiency and built-in current limiting, it's a workhorse module for powering motors, LED arrays, Raspberry Pi boards, or any 5V/12V load from a higher-voltage battery or wall adapter.

Onboard you'll find a turn-once trim potentiometer for setting the output voltage, two large 220µF electrolytic capacitors for input/output smoothing, and through-hole solder pads for sturdy connections. This is the basic version without an integrated voltmeter — pair it with a multimeter or a small panel meter when dialing in the output.

At a Glance

Specifications

Pinout Diagram

Wiring Guide

Code Examples

The XL4015 is a passive analog regulator — there is no microcontroller-side code to run. The "code" is in setting the trimpot before connecting your load. The examples below show how to monitor the output voltage from a microcontroller (useful for closed-loop battery management).

Arduino — Monitor Output Voltage with Voltage Divider

// Monitor XL4015 output rail with Arduino ADC
// Voltage divider: OUT+ -- 30k -- A0 -- 10k -- GND
// Divides up to 22V down to ~5.5V at A0 (Arduino 5V tolerant)

const int sensePin = A0;
const float DIV_RATIO = (30000.0 + 10000.0) / 10000.0;  // = 4.0

void setup() {
  Serial.begin(9600);
}

void loop() {
  int raw = analogRead(sensePin);
  float vAtPin = raw * (5.0 / 1023.0);
  float vRail = vAtPin * DIV_RATIO;
  Serial.print("Rail voltage: ");
  Serial.print(vRail, 2);
  Serial.println(" V");
  delay(500);
}

Raspberry Pi (Python) — ADS1115 Monitor

#!/usr/bin/env python3
# Use ADS1115 (16-bit ADC) to monitor XL4015 output
# Same divider: 30k + 10k from OUT+ to GND, ADS A0 reads middle

import time
import board, busio
from adafruit_ads1x15.ads1115 import ADS1115
from adafruit_ads1x15.analog_in import AnalogIn

i2c = busio.I2C(board.SCL, board.SDA)
ads = ADS1115(i2c)
chan = AnalogIn(ads, 0)

DIV_RATIO = 4.0  # 30k+10k / 10k

while True:
    rail = chan.voltage * DIV_RATIO
    print(f"Rail: {rail:.2f} V")
    time.sleep(0.5)

Frequently Asked Questions