// ESP32 kits — simulator-first

Simulate it free.
Then build it real.

Pre-flashed ESP32 project kits for Home Assistant. Run the circuit in our free online simulator first — then buy the box with the board, the firmware and the guide already inside.

Open the Free Simulator → Browse Kits
$ esptool write_flash kit-firmware.bin … OK — every board ships pre-flashed

// What is SensBench

SensBench is a free browser-based ESP32 & Arduino simulator with real firmware compilation — no installs, no signup.

free online simulator // no account· boards ship pre-flashed· build guide in every box· 30-day money-back
// how it works

Try it in the browser. Build it on your bench.

Three steps between you and a working smart-home device.

01

Simulate — free

Open the online simulator and run the exact circuit and firmware. No account, no install, no cost.

02

Buy the kit

One box with the pre-flashed board, every sensor and wire, an enclosure, and a printed quick-start.

03

Build & connect

Follow the photo guide. Home Assistant auto-discovers your device over local Wi-Fi. No cloud.

// ai builder

Describe It. The AI Builds It.

Plain English in — parts, wiring and compile-ready firmware out.

  • Tell the builder what you want — "garage door opener for Home Assistant, no cloud".
  • It picks the parts, draws the wiring table and writes the complete firmware — ready to compile.
  • 1 free call a day with any account — works in the AI Builder and over MCP. Credits and plans when you want more.
Try the AI Builder →See pricing
$ ai-builder --describe esp32-c3 · home assistant
// wiring table
| ESP32-C3 Pin | Component   | Function              |
| GPIO 21      | Relay (IN)  | open / close garage   |
| GPIO 22      | Reed switch | door position sensor  |
| GPIO 23      | Push button | manual trigger        |

// firmware (excerpt)
#define RELAY_PIN 21
#define REED_PIN  22
WiFi.begin(ssid, password);
server.on("/toggle", HTTP_GET, toggleGarageDoor);
server.on("/status", HTTP_GET, handleStatusRequest);
// actual AI Builder output, unedited
// the editor

A Real ESP32 Workbench in Your Browser

The free online simulator — no install, no account, no cost.

Virtual Breadboard

Drag parts onto the breadboard and connect pins — exactly like the real bench, minus the burnt fingers.

Real Compilation

Your actual sketch is built in the cloud by arduino-cli — the same toolchain as the desktop IDE.

Emulated ESP32

The virtual chip runs the same binary you would flash to real hardware. What simulates is what ships.

Live Serial Monitor

Watch your Serial.print() debug output scroll as the simulation runs. Probe, pause, re-run.

Sensors & Actuators

LEDs, relays, DHT22, OLED displays and more respond in real time as your firmware drives them.

Free, No Account

Open the tab and start building. Accounts only matter when you want AI generation or MCP access.

MCP Server for AI Agents

Your AI coding agent can drive the workbench directly — compile Arduino/ESP32 sketches, assemble circuits, and verify firmware through the sensbench MCP server. Works with Claude, Cursor, and any MCP-compatible client.

Get your MCP key →Docs →

// pricing

Free Every Day. Cheap When You Want More.

The simulator is free for everyone, forever. AI generation is metered — and every tier includes MCP access.

Free$0

Full simulator access, no account needed. 1 free call a day with an account — works in the AI Builder and over MCP.

Credits$1.99 / 5 builds

Pay as you go — credits never expire, valid in the AI Builder and over MCP. 20-build pack $6.99.

Maker$14.99 /mo

12 AI builds every day — in the AI Builder and over MCP. For weekend builders who iterate fast.

Pro$19.99 /mo

50 AI builds every day — in the AI Builder and over MCP. For classrooms, clients and production work.

// examples

243 Projects You Can Run Right Now

Every example opens directly in the simulator — circuit and firmware included.

esp32 · blink led esp32 · dht22 sensor esp32 · wi-fi scan all 175 examples →
// kits

Featured Kits

Pre-flashed. Local-first. Everything in the box.

ESP32 garage door opener kit contents: ESP32-C3 board, 2-channel relay module, HC-SR04 ultrasonic sensor, jumper wires and 3D-printed enclosure
Best Seller

Garage Smart Kit

ESP32 garage door opener for Home Assistant. Local Wi-Fi, no cloud, 10-minute wiring.

$29.99View Kit →
ESP32 plant watering kit contents: ESP32-C3 board, capacitive soil moisture sensor, water pump, relay module and breadboard
New

Plant Pal Kit

Self-watering plant monitor with soil sensor and pump. Logs everything to Home Assistant.

$24.99View Kit →
ESP32 mmWave presence sensor kit contents: ESP32-C3 board, 24GHz radar module, jumper wires and wall-mount enclosure
In Development

Presence Sensor Kit

24GHz mmWave true-presence detection — knows you're in the room even when you sit still.

$34.99Notify Me
// why sensbench

We Solder the Hard Parts First

So your evening project actually finishes in one evening.

Pre-flashed Firmware

Every board leaves the bench with tested firmware installed. Plug in, power up, it works.

Simulator-First

Run the project in the browser before you buy. What you simulate is what ships.

Guides With Photos

Every wire, every pin, every click — documented step by step, no guessing.

Local-First, No Cloud

ESPHome + Home Assistant over your own Wi-Fi. Your data never leaves the house.

Start With the Simulator. It's Free.

Build the circuit in your browser — if you like it, the kit is one click away.

Open the Simulator →

1 free call every day — AI Builder and MCP · 30-day money-back guarantee