KY-051 Voltage Translator / Level Shifter

Name: KY-051 Voltage Translator / Level Shifter
Brand: ESP32
Price: 3 USD
Availability: InStock

KY-051 Voltage Translator / Level Shifter image

View on Amazon

Overview

The KY-051 is a versatile voltage level shifter module that enables safe communication between devices operating at different voltage levels. With four bi-directional channels, it ensures compatibility and protects components from potential damage due to voltage mismatches.

Quick Navigation

📋 Specs 📍 Pinout 🔌 Wiring 🔧 Debug

Code Examples

Arduino

C++ Framework

ESP-IDF

Native Framework

ESPHome

YAML Configuration

PlatformIO

IDE & Toolchain

MicroPython

Python Framework

About KY-051 Voltage Translator / Level Shifter

The KY-051 Voltage Translator, also known as a Level Shifter, is designed to safely interface devices operating at different voltage levels. It features four channels that can convert digital signals either up or down, facilitating communication between components like microcontrollers and sensors with varying voltage requirements.

Technical Specs

KY-051 Specifications

Complete technical specification details for KY-051 Voltage Translator / Level Shifter

📊 Technical Parameters

Available Channels 4

Voltage Range (VCCa) 1.2V to 3.6V

Voltage Range (VCCb) 1.7V to 5.5V

Dimensions 24 x 17 x 11 mm

Weight 1 g

Download Full Datasheet

Pin Configuration

KY-051 Pinout

The **KY-051** is an 8-pin (4-channel) bidirectional level shifter module:

Visual Pinout Diagram

Pinout Diagram Primary

KY-051 Voltage Translator / Level Shifter pinout

Total Pins

Pin Types

Power

Communication

Quick Tips

🔌

**Interface**: 4-channel bidirectional level shifter,⚡ **IC**: TXS0108E or similar 8-channel voltage translator,🔄 **Bidirectional**: Signals can flow from A→B or B→A automatically

📊

**VCCa Range**: 1.2V to 3.6V (low voltage side),📊 **VCCb Range**: 1.7V to 5.5V (high voltage side)

⚠️

**Requirement**: VCCb must be ≥ VCCa,🎯 **Applications**: 3.3V ↔ 5V conversion, I2C/SPI/UART level shifting, sensor interfacing

Pin Descriptions

Pin Name	Type	Description	Notes
1 VCCa	Power	Low voltage reference	1.2V to 3.6V (e.g., 3.3V)
2 VCCb	Power	High voltage reference	1.7V to 5.5V (e.g., 5V)
3 GND	Power	Common ground	Shared between both sides
4 A1-A4	Communication	Low voltage side I/O	Connects to VCCa voltage device
5 B1-B4	Communication	High voltage side I/O	Connects to VCCb voltage device

Connection Guide

Wiring KY-051 to ESP32

To interface the **KY-051** for voltage level translation:

Pin Connections

KY-051 Pin	ESP32 Pin	Description
1 VCCa Required	3.3V	Low voltage reference (ESP32 side)
2 VCCb Required	5V (from external)	High voltage reference (5V device side)
3 GND Required	GND	Common ground
4 A1-A4 Required	ESP32 GPIO pins	Connect to 3.3V device I/O
5 B1-B4 Required	5V device I/O	Connect to 5V device I/O

💡

**Bidirectional**: No direction configuration needed - signals automatically translate both ways

⚡

**VCCa → ESP32**: Connect VCCa to ESP32 3.3V, A channels to ESP32 GPIO

⚡

**VCCb → 5V Device**: Connect VCCb to 5V supply, B channels to 5V device I/O

🔌

**Common Ground**: CRITICAL - both devices must share the same GND

📊

**I2C Compatible**: Can be used for I2C level shifting (connect SCL/SDA to A/B pairs)

📊

**SPI Compatible**: Works with SPI signals (MOSI, MISO, SCK, CS)

⚠️

**Speed**: Up to 60 Mbps typical, suitable for most digital protocols

🔋

**No External Components**: Built-in pull-up resistors on some versions

Help & Support

KY-051 Troubleshooting

Common issues and solutions to help you get your sensor working

Common Issues

Debugging Tips

Additional Resources

Datasheet

Technical specifications and guidelines

Code Examples

KY-051 Programming Examples

Ready-to-use code examples for different platforms and frameworks

#define LOW_VOLT_PIN 2  // Pin connected to low voltage side (e.g., 3.3V logic)
#define HIGH_VOLT_PIN 3 // Pin connected to high voltage side (e.g., 5V logic)

void setup() {
    pinMode(LOW_VOLT_PIN, INPUT);
    pinMode(HIGH_VOLT_PIN, OUTPUT);
    Serial.begin(9600);
    Serial.println("KY-051 Voltage Level Shifter Test");
}

void loop() {
    int low_signal = digitalRead(LOW_VOLT_PIN);
    digitalWrite(HIGH_VOLT_PIN, low_signal);
    Serial.print("Low Voltage Signal: ");
    Serial.print(low_signal);
    Serial.print(" -> High Voltage Output: ");
    Serial.println(digitalRead(HIGH_VOLT_PIN));
    delay(500);
}

This Arduino code tests the KY-051 voltage level shifter by reading a digital signal from a low voltage pin (3.3V logic) and shifting it to a high voltage pin (5V logic). It continuously reads the signal, shifts it, and prints both the input and output values to the serial monitor every 500ms.

#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/gpio.h"

#define LOW_VOLT_PIN GPIO_NUM_2  // Low voltage side (3.3V logic)
#define HIGH_VOLT_PIN GPIO_NUM_3 // High voltage side (5V logic)

void app_main() {
    gpio_pad_select_gpio(LOW_VOLT_PIN);
    gpio_pad_select_gpio(HIGH_VOLT_PIN);
    gpio_set_direction(LOW_VOLT_PIN, GPIO_MODE_INPUT);
    gpio_set_direction(HIGH_VOLT_PIN, GPIO_MODE_OUTPUT);
    printf("KY-051 Voltage Level Shifter Test\n");

    while (1) {
        int low_signal = gpio_get_level(LOW_VOLT_PIN);
        gpio_set_level(HIGH_VOLT_PIN, low_signal);
        printf("Low Voltage Signal: %d -> High Voltage Output: %d\n", low_signal, gpio_get_level(HIGH_VOLT_PIN));
        vTaskDelay(pdMS_TO_TICKS(500));
    }
}

This ESP-IDF code configures GPIO2 as an input (low voltage side) and GPIO3 as an output (high voltage side). It continuously reads the input signal, shifts it to the high voltage side, and prints the values to the console every 500ms.

sensor:
  - platform: gpio
    pin: GPIO2
    name: "KY-051 Low Voltage Signal"
    update_interval: 0.5s

binary_sensor:
  - platform: gpio
    pin: GPIO3
    name: "KY-051 High Voltage Output"

This ESPHome configuration sets up the KY-051 module to monitor a low voltage signal on GPIO2 and shift it to GPIO3. The signals are updated every 500ms.

platformio.ini

[env:esp32]
platform = espressif32
board = esp32dev
framework = arduino

main.cpp

#include <Arduino.h>

#define LOW_VOLT_PIN 2
#define HIGH_VOLT_PIN 3

void setup() {
    pinMode(LOW_VOLT_PIN, INPUT);
    pinMode(HIGH_VOLT_PIN, OUTPUT);
    Serial.begin(115200);
    Serial.println("KY-051 Voltage Level Shifter Test");
}

void loop() {
    int low_signal = digitalRead(LOW_VOLT_PIN);
    digitalWrite(HIGH_VOLT_PIN, low_signal);
    Serial.printf("Low Voltage Signal: %d -> High Voltage Output: %d\n", low_signal, digitalRead(HIGH_VOLT_PIN));
    delay(500);
}

This PlatformIO code configures GPIO2 as an input and GPIO3 as an output to test the KY-051 voltage level shifter. It reads the signal from the low voltage side and shifts it to the high voltage side, printing the results to the serial monitor every 500ms.

import machine
import time

LOW_VOLT_PIN = machine.Pin(2, machine.Pin.IN)
HIGH_VOLT_PIN = machine.Pin(3, machine.Pin.OUT)

while True:
    low_signal = LOW_VOLT_PIN.value()
    HIGH_VOLT_PIN.value(low_signal)
    print("Low Voltage Signal:", low_signal, "-> High Voltage Output:", HIGH_VOLT_PIN.value())
    time.sleep(0.5)

This MicroPython script configures GPIO2 as an input and GPIO3 as an output for the KY-051 voltage level shifter. It continuously reads the low voltage signal, shifts it to the high voltage side, and prints the values every 500ms.

Summary

Wrapping Up KY-051

The ESP32 KY-051 Voltage Translator / Level Shifter is a powerful KY-0xx module sensor that offers excellent performance and reliability. With support for multiple development platforms including Arduino, ESP-IDF, ESPHome, PlatformIO, and MicroPython, it's a versatile choice for your IoT projects.