Wokwi Automation Scenarios

Automate simulations in Wokwi using YAML-based automation scenarios. Simulate button presses, sensor input, and verify serial output to test firmware programmatically.

Automation scenarios allow you to automate the simulation, push buttons, change the state of the sensors, and check the serial output. You can use automation scenarios to test your firmware in a realistic environment, and verify that it behaves as expected.

Each automation scenario is a YAML file that describes a sequence of actions that the simulator should take. You can use the --scenario CLI option to load an automation scenario file.

Scenario File Structure

The basic structure of an automation scenario file is as follows:

name: 'Your scenario name'
version: 1
author: 'Your name'

steps:
  # List of steps:
  - set-control:
      part-id: btn1
      control: pressed
      value: 1
  - delay: 500ms
  - wait-serial: 'Button 1 pressed'

Automation scenarios are currently in alpha. The API is not fully documented yet, and may change in the future. You can use the example projects as a reference.

Available Steps

These can be used as a sequence of actions to perform when running the scenario. Use these to build a list of steps for testing your project.

Wait (delay)

Wait for an amount of time.

Parameters

Name	Description
value	Amount of time to wait for. Units are required (e.g. 200ms)

Example Usage

delay: 30ms

Assert Pin Value (expect-pin)

Check if a pin is set to an expected value.

Parameters

Name	Description
part-id	ID of the target component
pin	Name of pin to check
value	Expected value of the pin

Example Usage

expect-pin:
  part-id: esp
  pin: 2
  expected: 1

Control a Part (set-control)

Set a controllable part of a component to a specified value. View part documentation for available controls or see a list of supported parts below.

Parameters

Name	Description
part-id	ID of the target component
control	Aspect of the target component to modify (e.g. temperature, humidity)
value	Value to set the control to

Example Usage

set-control:
  part-id: dht
  control: humidity
  value: 39

Wait and Match Text from Serial (wait-serial)

Wait for serial console output which matches a given string.

Parameters

Name	Description
text	String to wait and match for

Example Usage

wait-serial: 'Ready for testing!'

Write to Serial (write-serial)

Write text or an array of numbers to the serial console.

Parameters

Name	Description
value	The string or array of numbers to write to the serial console

Example Usage

String

write-serial: 'Ready for testing!'

Array

write-serial: [87, 111, 107, 119, 105]

Take a Screenshot (take-screenshot)

Take a screenshot of a specific component and compare it with an existing capture.

Parameters

Name	Description
part-id	ID of the target component
save-to	Path to save screenshot to
compare-with	Path of a screenshot to compare with

This step requires part-id and save-to and/or compare-with.

Example Usage

take-screenshot:
  part-id: 'oled1'
  compare-with: 'screenshots/oled-1.png'

Touch a Part (touch)

Simulate a touch tap on a part with a touchscreen. Sends a press event at the given coordinates, and automatically releases after duration.

Parameters

Name	Description
part-id	ID of the target part (e.g. the board with a touchscreen)
x	X coordinate (touch controller coordinates)
y	Y coordinate (touch controller coordinates)
duration	How long to hold the touch (optional, default: 50ms)
wait	If true, wait for the touch duration before continuing (optional, default: false)

Example Usage

touch:
  part-id: esp32s3box
  x: 120
  y: 160
  duration: 100ms

Touch Press (touch-press)

Low-level touch command: send a press event at the given coordinates. Pair with touch-release to complete the gesture.

Parameters

Name	Description
part-id	ID of the target part
x	X coordinate (touch controller coordinates)
y	Y coordinate (touch controller coordinates)

Example Usage

touch-press:
  part-id: esp32s3box
  x: 120
  y: 160

Touch Move (touch-move)

Low-level touch command: send a move (drag) event to new coordinates. Use between touch-press and touch-release.

Parameters

Name	Description
part-id	ID of the target part
x	X coordinate (touch controller coordinates)
y	Y coordinate (touch controller coordinates)

Example Usage

touch-move:
  part-id: esp32s3box
  x: 150
  y: 200

Touch Release (touch-release)

Low-level touch command: release the touch.

Parameters

Name	Description
part-id	ID of the target part

Example Usage

touch-release:
  part-id: esp32s3box

Touch Coordinate System

Touch coordinates use the touch controller’s coordinate space, matching real hardware behavior. For most display+touch combinations (e.g. ILI9341 with FT6206), the touch controller’s origin (0, 0) is at the bottom-right of the display, not the top-left.

Your firmware is responsible for mapping touch coordinates to display coordinates, just like on real hardware. For example, with the Adafruit FT6206 library on a 240x320 ILI9341 display:

TS_Point p = ts.getPoint();
// Flip to match display coordinates
p.x = map(p.x, 0, 240, 240, 0);
p.y = map(p.y, 0, 320, 320, 0);

Drag Gesture Example

Combine the low-level touch commands to simulate a drag gesture:

- touch-press:
    part-id: esp32s3box
    x: 50
    y: 100
- delay: 50ms
- touch-move:
    part-id: esp32s3box
    x: 150
    y: 100
- delay: 50ms
- touch-release:
    part-id: esp32s3box

Running Scenarios

To build the test projects and run the tests, you need to install PlatformIO Core and the Wokwi CLI, get a Wokwi CI token and set the WOKWI_CLI_TOKEN environment variable with the token.

You can then use pio run to compile the project and wokwi-cli . --scenario <scenario_file>.yaml to run the tests. You can also use Wokwi for VS Code to interactively simulate the test projects.

Example Usage

Example parts with test scenarios are available at the wokwi-part-tests GitHub repository. We will try to compile and run tests for the wokwi-dht22 part on the ESP32.

1. Clone the Repository

   Begin with cloning the repository:

   git clone https://github.com/wokwi/wokwi-part-tests
   
2. Navigate to the Test

   Navigate to the part in question:

   cd wokwi-dht22/dht22-esp32
   
3. Build the Firmware

   Build the required microcontroller firmware:

   pio run
   

   This can also be done via the PlatformIO VS Code extension - just click the build button.

4. Run the Test

   Finally, run the test:

   wokwi-cli . --scenario dht22.test.yaml
   

If successful, the output of the test looks as follows:

Wokwi CLI v0.18.3 (786fa8e49d9c)
Connected to Wokwi Simulation API 1.0.0-20251028-g60747fe2
Starting simulation...
ets Jul 29 2019 12:21:46
[DHT22 Sensor Test (ESP32)] Expected text matched: "ets Jul 29 2019 12:21:46"

rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0030,len:1156
load:0x40078000,len:11456
ho 0 tail 12 room 4
load:0x40080400,len:2972
entry 0x400805dc
DHT22 test!
[DHT22 Sensor Test (ESP32)] Expected text matched: "DHT22 test!"
Humidity: 45.80%  Temperature: 23.50°C
[DHT22 Sensor Test (ESP32)] Expected text matched: "Humidity: 45.80%  Temperature: 23.50°C"
Humidity: 45.80%  Temperature: 23.50°C
[DHT22 Sensor Test (ESP32)] Expected text matched: "Humidity: 45.80%  Temperature: 23.50°C"
Humidity: 66.90%  Temperature: 21.50°C
[DHT22 Sensor Test (ESP32)] Expected text matched: "Humidity: 66.90%  Temperature: 21.50°C"
[DHT22 Sensor Test (ESP32)] Scenario completed successfully

Supported Parts with Automation Controls

Several Wokwi parts support automation controls that can be controlled using automation scenarios. These controls allow you to programmatically change the state of sensors, press buttons, and modify component values during simulation.

Parts with Automation Controls

Push Button

Control button presses and releases

Potentiometer

Adjust the potentiometer position

MPU6050 Sensor

Set acceleration, rotation, and temperature values

Analog Joystick

Set direction and pressed state

HX711 Load Cell

Set load value of scale

Photoresistor Sensor

Set lux value

Each part’s documentation page contains detailed information about the specific automation controls available, including control names, types, and example usage.