TurtleBlock Studio

Pico W simulator: try blocks without a board

By Turtleback Robotics Academy · Updated 15 October 2026

Free ($0) is the block builder and the Pico W simulator. Standard ($30/month) adds ESP32, Raspberry Pi, Makeblock, USB upload, and .py downloads. Premium ($50/month) adds online project saves.

You can try a program before you plug in a board. Leave the board on Raspberry Pi Pico W, press Simulate, then press Run Blocks. The simulator shows pin levels, a virtual lamp, a virtual motor, and a terminal log. No account is needed. A Pico W on your desk is optional.

What you are looking at

The Simulate button opens the simulator view. Three windows are listed: Visual, Terminal, and Split. Visual is the pin picture and the device cards. Terminal is the log. Split shows both. Run Blocks walks through the blocks. Run Code walks through the code in the editor. Reset clears the run so you can start again.

The pin picture matches the Pico W header when that board is selected. A GPIO pin shows HIGH or LOW and a percent. Power pins, ground pins, and special pins are labeled too. The run does not wait out every delay. A wait of 500 milliseconds is a log line that says the delay was simulated. A long forever loop stops after a limited number of steps, and the screen keeps the pin levels from that run.

Two cards sit under the pins. Virtual Lamp follows one GPIO pin. It starts on GP12 until a pin write chooses another pin. Virtual Motor starts mapped to IN1 GP10 and IN2 GP11, and it shows FORWARD, REVERSE, or STOPPED with a speed percent. Sliders on the side can change virtual sensor values, including the CPU temperature, so an if block has a number to test. Those sliders are pretend inputs. They are not the sensors on a real board.

  1. Press Open Studio. No account is needed, and you do not need a cable.

  2. Leave the board on Raspberry Pi Pico W. The header picture is for that board.

  3. Open Samples and choose Blink an LED.

  4. Press Simulate. Choose Terminal or Split so you can read the log.

  5. Press Run Blocks. The onboard LED block writes a log line, Onboard LED, then ON or OFF. The wait block writes Delay 500 ms (simulated). The light on the Pico W header is not a separate blinking cartoon. Read the log.

  6. Open the Traffic Light sample if you want pins you can see. It uses GP14, GP15, and GP16. The log lists lines such as [pin] GP14 -> HIGH. The first pin write also aims the Virtual Lamp at that pin.

  7. Press Reset when you want a clean run. To use a real Pico W later, switch to Chrome or Edge, plug in the board, and press Connect Board.

Log lines a blink run writes

Onboard LED -> ON
Delay 500 ms (simulated)
Onboard LED -> OFF
Delay 500 ms (simulated)

What the simulator does not do

It does not play a buzzer sound. A buzzer block only adds a log line with the pin, the frequency, and the time. It does not give you a clickable button. The button block reads a pin, and there is no button picture to press. Try the traffic-light outputs in the simulator, and use a real button when you want a press. Keypad, infrared, and RFID blocks log that they are not simulated.

The simulator is the practice view for the board you selected, and the header drawing is the Pico W drawing. ESP32 has a pin grid instead of that header picture. It is not a separate ESP32 cartoon. Makeblock is copy-and-run Python, not a robot on this screen. Practice the block shapes on Pico W, then read the ESP32 guide or the Makeblock guide when you change boards.

Firefox and Safari can open the studio and this simulator. USB upload uses Chrome or Edge, because that is where the browser’s Web Serial support is. You can do a whole first lesson with no board at all.

Keep your practice

Blocks stay in this browser. You can refresh and still see them. Loading a sample replaces the workspace, and the studio saves that sample into the browser recovery draft. There is no online project folder on this site. Copy the code if you want a backup outside the browser.

The blink guide is the shortest first project. The traffic light guide is the next one when you want three lights, a button, and a buzzer block. The getting started guide adds the USB step for a real Pico W.

Common questions

Do I need a Pico W to use the simulator?

No. Open the studio, leave the board on Raspberry Pi Pico W, and press Simulate, then Run Blocks. A real board is a later step.

Why does the blink not keep flashing on the pin picture?

Run Blocks walks the blocks, writes the log, and then shows the pin levels from that run. The onboard LED messages are in the terminal. The header picture does not play a forever animation.

Can I simulate an ESP32 or a Makeblock robot here?

Practice on the Pico W board. ESP32 is not a separate animation. Makeblock Python runs on a computer with the robot, not as a car on this page.

Which browser works?

The simulator opens in the studio, including Firefox and Safari. Connecting a real board with USB uses Chrome or Edge.

More guides

Start Here: Open Studio