LM-2596 Module Without LED

• VIN+ / VIN−: DC input (observe polarity).
• VOUT+ / VOUT−: Regulated DC output.
• ADJ: Trimmer potentiometer to set output voltage.
• Ground: VIN− and VOUT− share a common ground.

Tip: For high currents, use thicker wires and keep leads short to minimize losses.

Basic connection showing VIN from power source and VOUT to load.

Measure VOUT (Voltage Divider)

// Example: Monitor LM2596 output voltage via divider to A0
const byte SENSE = A0;
const float R1 = 100000.0; // top resistor (to Vout)
const float R2 = 33000.0;  // bottom resistor (to GND)
const float VREF = 5.0;

void setup(){ Serial.begin(115200); }
void loop(){
  int raw = analogRead(SENSE);
  float vA0 = raw * (VREF / 1023.0);
  float vOut = vA0 * ((R1 + R2) / R2);
  Serial.print("Vout: "); Serial.print(vOut, 2); Serial.println(" V");
  delay(500);
}

ESP32/ESP8266: Sense VOUT through a divider to keep the ADC pin ≤ 3.3 V at worst case.

ESP32: ADC Read + Divider

// ESP32 dev board — divider from Vout to GPIO34 (input-only ADC)
// Keep Vadc ≤ 3.3 V at max Vout.
const int PIN_ADC = 34;
const float R1 = 100000.0;   // to Vout
const float R2 = 33000.0;    // to GND

void setup(){
  Serial.begin(115200);
  analogReadResolution(12);  // 0..4095
}
void loop(){
  int raw = analogRead(PIN_ADC);
  float vadc = (raw / 4095.0) * 3.3;
  float vout = vadc * ((R1 + R2) / R2);
  Serial.printf("ADC:%d  Vout:%.2f V\n", raw, vout);
  delay(300);
}

ESP8266: ADC Read (A0)

// Many ESP8266 boards scale A0 to ~1.0 V. Check your board's reference.
// If needed, change 'vadc' scale or add your own divider to keep A0 ≤ reference.
const float R1 = 100000.0, R2 = 33000.0;

void setup(){ Serial.begin(115200); }
void loop(){
  int raw = analogRead(A0);              // 0..1023
  float vadc = raw * (1.0 / 1023.0);     // if 1.0 V ref on your board
  float vout = vadc * ((R1 + R2) / R2);
  Serial.printf("ADC:%d  Vout:%.2f V\n", raw, vout);
  delay(300);
}

ESP-IDF example reading ADC1 with 11 dB attenuation (~0–3.3 V). Convert to Vout using your divider ratio.

ESP32 (ESP-IDF C): ADC + Calibration

#include "driver/adc.h"
#include "esp_adc_cal.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include 

#define ADC_CH   ADC1_CHANNEL_6   // GPIO34
#define SAMPLES  16

void app_main(void){
  adc1_config_width(ADC_WIDTH_BIT_12);
  adc1_config_channel_atten(ADC_CH, ADC_ATTEN_DB_11); // ~0..3.3 V

  esp_adc_cal_characteristics_t cal;
  esp_adc_cal_characterize(ADC_UNIT_1, ADC_ATTEN_DB_11, ADC_WIDTH_BIT_12, 1100, &cal);

  const float R1 = 100000.0f;  // to Vout
  const float R2 = 33000.0f;   // to GND

  while (1) {
    uint32_t sum = 0;
    for (int i=0; i

Never exceed the ADC pin’s max input. Pick R1/R2 for your highest expected Vout.

Read Voltage via MCP3008 ADC

# pip install adafruit-circuitpython-mcp3xxx
import time
import board, busio
from digitalio import DigitalInOut
from adafruit_mcp3xxx.mcp3008 import MCP3008
from adafruit_mcp3xxx.analog_in import AnalogIn

spi = busio.SPI(clock=board.SCK, MISO=board.MISO, MOSI=board.MOSI)
cs  = DigitalInOut(board.CE0)
mcp = MCP3008(spi, cs)
chan = AnalogIn(mcp, MCP3008.P0)

R1 = 100000.0
R2 = 33000.0

while True:
    va0 = chan.voltage
    vout = va0 * ((R1 + R2) / R2)
    print(f"Vout: {vout:.2f} V")
    time.sleep(1)

No specific drivers are required for the LM-2596 module. USB-serial adapters may need bridge drivers.

• CH341 Driver (GitHub)

Arduino

• Arduino Project Hub
• Arduino Playground
• Arduino IDE Download
• Install Arduino Libraries

Raspberry Pi

• Raspberry Pi Projects
• GPIO Zero Docs
• Raspberry Pi Docs
• Raspberry Pi Software
• Pi Getting Started

Espressif

• ESP-IDF Programming Guide (Official)
• ESP-IDF “Get Started”
• Espressif Technical Docs / Datasheets
• Espressif Docs (ReadTheDocs)
• ESP-IDF on GitHub
• ESP-IDF Examples
• ESP8266 RTOS SDK Docs
• ESP8266 RTOS SDK (GitHub)
• ESP-Matter Docs
• ESP-Matter (GitHub)
• PlatformIO + ESP-IDF
• Arduino Core for ESP32 (GitHub)

Drivers / Other

• CH341 Driver (GitHub)

Note: Specs vary by vendor/board revision; verify on your PCB silkscreen.

Important Notice: For educational, prototype, experimental, laboratory and R&D use only. (non-RoHS)

WEEE

Not subject to WEEE marking; obligations apply to final equipment.

Manufacturer

Little Muffins Things Limited
166 River Heights, 90 High Street
London E15 2GQ
littlemuffinsthings.com

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