Configuring Variables and Calculating Prices

Before jumping into the process of creating the pie, please make sure you have accessed all the necessary design assets we’ve prepared for you:

Access the Starting Pie File with Instructions.

Click the file link and open it in ProtoPie Studio.

. You’ll be using them a lot throughout your prototyping journey to add realism and depth.

Select the group layer you wish to scroll.

 Group content within scroll containers for smoother interactions.

Next, let’s connect user inputs (Triggers) to visual behaviors (Responses).


Example:  Coffee Size Selector (Curto, Medium, Venti)

 response, setting Curto border opacity to 

Add two additional Border responses to set Medium and Venti borders to 

 Resetting border opacity ensures clarity in selections.

Now let’s add Toggle interactions like toppings selection effectively with Conditions and Logic.


 Conditions and Variables are key for toggles.

To create a true high-fidelity prototype, you’ll want the pie to have more than mere visual responses. Most prototypes require some logic to put 2 and 2 together!

To achieve that in ProtoPie, you can easily manage selections using Variables and Dynamic Calculations.


Add scene-specific variables: CURTO, MEDIUM, VENTI, WhippedCream, Ice, total_price.

Enable debug mode to verify variable values.

(CURTO * 4.59 + MEDIUM * 5.39 + VENTI * 6.79) + (WhippedCream * 3.06) + (Ice * 2.00)

Detect changes in total_price to highlight selections (e.g., color #D8FF99).

 Use debug controls to verify your logic.

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 Submit via our survey or use the hashtag 

Building Interaction Design Systems with Conditions & Variables

Make your prototypes stand out by mastering our Simple Pies Series to quickly learn essential prototyping skills.

Learn Fast with our Simple Pies Series: Build Interactive Prototypes Easily

Static mockups are fine - until they aren’t. Especially in FinTech, where real-time insights matter, a simple image won’t cut it. To create a truly immersive and realistic user experience, you need dynamic, live data. Imagine your prototype's expense charts and financial data updating in real-time, just like a finished product.

In this tutorial, we'll walk you through a step-by-step guide on how to integrate Google Sheets with your ProtoPie prototypes. This guide will show you how to pull data directly from a spreadsheet to create powerful, data-driven prototypes.

Part 1: Retrieving Your Google Sheets Data

The first step is to get your data from Google Sheets into ProtoPie. We'll use ProtoPie Connect and its built-in API plugin to make this happen.

Step 1: Set Up the API Request in ProtoPie Connect

In the ProtoPie Connect API plugin, you'll need to create a new request with the following details:

 The URL is a combination of your Spreadsheet ID, the data range you want to import, and your unique Google API key.

The Spreadsheet ID is the unique identifier for your Google Sheet.

You can find it directly in your Google Sheet's URL. It's the long string of characters located between /d/ and /edit.

Next, you need to tell ProtoPie which data to grab. The range specifies the cells you want to import.

This can be a set of columns (e.g., A:C) or the entire sheet.

You can specify the sheet name and range using formats like Sheet1!A1:D1 or just list the sheet name to import all its data.

Step 4: Generate Your Google Sheets API Key

This key authorizes ProtoPie to access your sheet data.

3. In the search bar, look for the "Google Sheets API" and 

6. Your key will be generated. Copy it and add it to your URL in ProtoPie Connect.

Once you've put together your URL, test the request in ProtoPie Connect. If you get an error, the most common issue is the sharing permission on your Google Sheet.

 Make sure your Google Sheet's sharing setting is changed from "Restricted" to 

 A restricted sheet requires an OAuth authorization, which could be used if you want to keep your data restricted but still use it in your prototype. Though that type of authorization will not be covered in this tutorial.

Once the API request is successful, ProtoPie receives a long string of raw data from your sheet. Now, we need to parse this data (break it apart) so we can use it in our prototype.

The data from Google Sheets is organized into "values," which represent the rows in your spreadsheet. The first row typically contains your column titles (e.g., "Name," "Date," "Amount"), and the subsequent rows contain the actual data.

Step 1: Parsing Basic Data with parseJson

The parseJson() formula is the key to accessing specific pieces of information. Let's look at a basic example for retrieving metadata:

 parseJson(metaData "values."+ (ID+1)+".0")

This is the variable where you assigned to store the raw data from the API call.

 This tells the formula to look inside the "values" section of the data.

 This selects the row you want. We use +1 because the first row (row 0) is usually the titles, and we want to access the actual data rows that follow. So, to get data from the first data row (which is the second row in the sheet), you look in the second set.

This selects the specific item within the row. Data items in each row are indexed starting from 0. So, .0 gets the first item, .1 gets the second, and so on.

Step 2: An Advanced Example for Dynamic Chart Data

Sometimes, the data structure from Google Sheets isn't ideal for direct parsing. For instance, if you have monthly expenses listed year by year, finding a specific month's expense requires a workaround.

 parseJson(googleSheet,"values."+((year*12)+ monthID +1)+".2")

This formula might look complex, but it's just using math to pinpoint the exact data we need.

We use variables for the desired year and 

 This part does the heavy lifting. If your data has 12 months for each year, this calculation skips down the rows in blocks of 12 to get to the correct year.

: After finding the right year, this adds the month's number to find the right row.

: This would grab the third piece of data in that row (e.g., the expense amount).

And there you have it! By connecting Google Sheets to ProtoPie, you can move beyond static designs and build prototypes that are as dynamic and responsive as the real thing. You can now pull live data to power charts, lists, and other components, creating a richer, more convincing user test.

Remember to generate your own Google API key and set your sheet's permissions correctly.

Go beyond static mockups by integrating Google Sheets with ProtoPie to create dynamic, data-driven prototypes that respond in real time.

Effortless Integration: Connecting Google Sheets to Your ProtoPie Prototypes

There have been discussions recently about team collaboration in ProtoPie and what kinds of best practices there might be. One of the strengths (and weaknesses) of ProtoPie, much like Figma, is that there are often multiple ways to achieve the same result. While this is beneficial for rapid development, it can pose challenges for team collaboration.

 is a crucial step in simplifying collaboration. Learning to build well-structured, reusable components is a key skill for effective teamwork. This tutorial will demonstrate some best practices for constructing reusable components within a ProtoPie library.

For this guide, I will be using components within a local pie. However, for team collaboration, these would ideally be built in a shared library. This allows updates to be shared among the team, ensuring consistency across all pies.

To keep things simple and make the core concepts clear, I'll use the humble radio button as our example. Imagine a game with an initial screen where the user must choose a player ('Player 1' or 'Player 2') or a difficulty level ('Easy' or 'Hard').

The starter Pie for this tutorial has this exact setup, but it's all hard-coded, with no attempt at reusability. If you examine the file, you’ll immediately see the potential for reusability, as the code for all four of the radio buttons is essentially the same.

To truly understand the value of components, try adding a third difficulty level ('Moderate') to the starter pie. You'll find that this requires numerous edits, and it's easy to miss a small change and break the prototype. Furthermore, as you add more buttons, the list of triggers and responses for the scene becomes increasingly congested, and that's just to make the radio buttons work, without even considering the interactions that react to their input.

Once you're convinced of the benefits, we can proceed with the following steps.


Select the container named “Name Buttons” and choose Create Component. Rename the component to “Radio Buttons” and begin editing it. Ensure the Container Layer is set to Auto Layout (Hug and Hug). Finally, change the name of the text variable “Name” to “Value”.

Select "Button 1," copy it, and use “Paste with Linked Triggers” five times. You should now have six radio buttons, with layers named from Button 1 to Button 6.

Go through all the layers within the component and edit the layer names to be accurate. For example, the "Label" field in "Button 4" should be renamed to "Label 4" instead of "Label 1."

Next, review the list of triggers and responses. Change the descriptions to accurately reflect what each one needs to do. It's much better to do this before editing the responses, as it makes it easier to review each action against its description.

Now, edit the actual triggers and responses. The assignment of a label to the 'value' variable needs to be adjusted for reusability. Instead of "Player 1," use expressions like ‘Label 1’.text. With six buttons, you'll also need to ensure that five buttons are turned off when one is turned on. This means the response for setting the opacity of 'On 2' to 0 needs to be duplicated four times for the additional buttons.

Preview the component to ensure that the new buttons update the correct indicator.

We need a way to send the updated value back to the main scene. To do this, add a trigger for the 'value' variable and use it to send a new message (let's call it NEWVALUE) to the parent. Include the 'value' variable as a parameter in this message. After setting this up, you can return to the scene.

Back in the main scene, delete the old “Difficulty buttons” container. 

Drag a new instance of the “Radio Buttons” component into the scene and name this layer “Difficulty buttons.”

The instance that is already there should be renamed to “Name Buttons.”

Step 9: Receive Messages from the Component

Add a Receive trigger to the scene to listen for the NEWVALUE message from the child component.

Assign its parameter to the appropriate variable. 

Then, duplicate this trigger and configure it for the other child component and the other variable.

In the "Name buttons" instance, decide how many player options you want and hide the remaining radio buttons. Change the labels for the visible buttons as needed. Repeat this process for the "Difficulty buttons" set.

You should now have a functioning prototype with two sets of radio buttons. You can preview the pie and see the correct values being assigned to the 'Name' and 'Difficulty' variables. While the button labels are correct now, we will explore further customizations next time.

If you compare our starting point with our final result, we now have a scene with very simple triggers and a robust component that can deliver any set of 2-6 radio buttons as needed. Adding a third set of buttons is now a straightforward task.

In the next tutorial, we will enhance this component further, adding the ability to display selected buttons differently and perhaps even incorporating different selection behaviors.

For an even more in-depth guide, see the full process in action in this video walkthrough by 

 ProtoPie Reusable Components Tutorial Part 1

A Step-by-Step Tutorial by David Gilmore for Better Team Collaboration.

A Guide to Creating Reusable Components in ProtoPie - Part 1

The need for prototypes that feel as if you’re actually moving

Nothing beats UX testing on ‘the real thing. ’ But when you’ve spent any time working in automotive HMI design, you know that testing your designs in an actual prototype car is a rare luxury. 

If you’re lucky, you may have access to a buck setup for judging your UI visuals and ergonomics in a semi-realistic layout.


The lack of realism gets particularly tricky when user testing. As a researcher, you’ll have to do a lot of explaining to provide your test users with enough context to understand what they’re looking at (“

Now imagine you’re driving on the highway at 120km/h.

RemotiveLabs has developed something that could alleviate this missing realism. Their tools provide streams of real vehicle data (telemetry, location, etc.), which can help automotive software developers test applications with realistic data in their simulators.


This allows for multiple ways to power simulations: 

Choose from a pre-made library of sample recording,

Upload your own signal data files (e.g., BLF, ASC, or MF4)

Or even connect an actual vehicle for a live data stream to test your HMI designs under real-world conditions.

Wouldn’t it be nice if we could test our interactive car UI prototypes with real car data?


Test prototypes of instrument clusters with realistic data (-visualizations).

Use vehicle data to bring infotainment mockups to life.

Duct tape a touch screen into any car and feed live data into a prototype UI.

Being curious how easy it is for an automotive UX designer like myself to incorporate this into a real-world design prototype, I decided to try and integrate RemotiveLabs’ tools into a typical UI design workflow.

Our UI Experiment: Figma, Protopie, and RemotiveCloud

Today’s de facto UI design tool is Figma. Design teams and their stakeholders use it to collaboratively iterate on design proposals.

Ideally, these design iterations also include testing:

Designers need to test their design proposals to evaluate the dynamic aspects of their concepts ‘in motion.’

User researchers need to do user tests with actual users to test intuitiveness, learnability, and ergonomic factors.

Unfortunately, Figma’s prototyping features are a bit rudimentary and usually not sufficient for automotive purposes. So, for interactive prototyping, I prefer another tool: Protopie.

RemotiveCloud streaming vehicle data into an HMI prototype on a touch display


In the automotive world, Protopie is a popular prototyping platform because it allows the use of multiple simultaneous (touch) displays, sensors, and complex conditional logic. 

We will need a Protopie license that includes Protopie Connect (an add-on to Protopie that allows prototypes to communicate with external devices and data sources).

To begin with, we’ll take the  automotive dashboard UI from Figma and bring it into Protopie to add the interactivity.

Once we have the prototype set up in Protopie, we’ll make a connection with RemotiveLabs’ toolset and drive various objects in our UI with streams of vehicle data.

If we can figure out how to do this, the world’s our oyster: we can use real vehicle data as parameters for controlling any aspect of our user interface.


Above is the HMI design for a fictitious urban micro car

We will be making an infotainment screen for a fictitious urban mini-mobility vehicle. It has a basic central touchscreen, which functions as both a simple infotainment screen and as the instrument cluster.

The vehicle is designed for short trips around town (typically < 30 minutes), so functionality-wise, we will keep the system simple:

An instrument cluster with the basic information needed for driving the vehicle.

A music section, which offers digital radio and a Bluetooth music connection to your phone.

Let’s go: setting up the demo project in Figma

In this experiment, we’ll be feeding real vehicle data into various aspects of the instrument cluster section of the screen.

To make this work, we don’t need to do anything special in Figma. We can set up the design as we always do. Needless to say, it will make everyone’s lives easier if all layers have meaningful names - but that’s good practice, anyway.


Getting your Figma frames into Protopie is literally easy as pie. The kind folk at Protopie provide a plugin for Figma, which lets you import frames from Figma and turn them into fully editable Protopie “scenes”.

Your Figma design will typically carry over 95% intact. The main things I have seen break in the conversion are:

Background blurs (for that popular frosted glass effect)

Image aspects, which can typically be easily corrected in Protopie

To bring gradients (e.g., for masks) over from Figma to Protopie, I recommend copying the gradient layers in Figma as SVG and pasting them in Protopie.

Download ProtoPie's Figma Import Plugin here: 

Preparing the ProtoPie for real-time data inpu

The first thing we need to do is to make any layer or object that we want to manipulate ready to receive changes. We do this by selecting the objects and clicking the “Make editable” button for each of them.

Again, double-check that each layer has a meaningful name because you will need to find them back in a dropdown list.

Once all the layers you want to manipulate using real-time data are editable, it’s time to set up the RemotiveLabs data stream we want to use.


Selecting the vehicle data parameters we want to use in our prototype

For my experiment, I’ve been using the free trial license of 

, which gives access to a number of trial recordings that provide dozens of different variables and signals to feed into our demo.

In the web environment, we can cherry-pick the signals we want to use in our prototype. And there’s no need to do it all at once; we can always come back later to add or remove signals from our selection.

I prefer to use VSS signals when they’re an option over OEM-specific signals. VSS stands for “Vehicle Signal Specification”, a standardization protocol for automotive data from Covesa. 

 The nice thing about VSS is that all signals have meaningful, descriptive names. 

Sometimes, it takes a bit of searching for the right signal name, but usually, they are quite easy to identify thanks to their naming format:

Vehicle.Powertrain.TractionBattery.StateOfCharge.Displayed


The signal names are important! We will need to refer to these in our prototype.


When we’re done we can look up the exact configuration command needed for running our prototype. We’ll paste this command in a terminal window later, so make sure you save it in a location where it can be easily retrieved every time we want to run our prototype.


RemotiveCloud natively supports Protopie communication

Feeding the VSS signals into our ProtoPie

There’s one last thing we need to do in Protopie before we can run our prototype: make the Pie listen and respond to the VSS signals we selected from the RemotiveCloud stream.

Make a global variable, e.g., a numerical variable named “speed”

Make a trigger that will respond when it receives a VSS signal from Protopie Connect. It will listen to the name we found in the data stream, e.g., “Vehicle.Speed”

Add the response: We can put the value we received in a text layer we prepared for this purpose (or change the color of an object, make something [in]visible, etc.).


That’s all. Obviously you can use all of Protopie’s extensive logic features to add complex conditional functionality and rich visualisations, way beyond just changing a number on the screen.


Tell Protopie how to receive vehicle data and what to do with it

Getting the prototype to run for the first time

We’re now only a few steps away from seeing our prototype run with real data!


Save your Pie (the Protopie file) on a local drive, so Protopie Connect can get access to it. Then, run Protopie Connect and locate your local prototype.

Press the little “Display” button next to your imported Pie to open up a Protopie demo window. This is the window our interactive prototype will run in.

2. Open the RemotiveCloud in a browser window

Go to the browser tab where we configured our data stream. Press Play to start sending data. You may need to restart the stream at some point if it runs out before we’re done (depending on the length of the selected stream).

3. Perform some command-line magic in a Terminal window

Next, open a terminal window and paste our command line string into it (assuming you have already installed RemotiveCLI. If not, this is a great time for that). RemotiveCLI will serve as our bridge between the data streaming from the RemotiveCloud and our Protopie demo.

Protopie Connect, showing the incoming data stream




When everything is set up correctly, it should automatically detect that both Protopie Connect and our RemotiveCloud data stream are in place: you should see all the relevant data points scrolling by in the Protopie Connect window.

A hands-on tutorial on using ProtoPie, RemotiveCloud and Figma to bring car UIs to life with actual vehicle signals.

Automotive UI Prototyping with Real Car Data

 emerges as a powerful ally for game designers and developers, offering a user-friendly platform to prototype real-world scenarios effortlessly. Combined with Unreal Engine, the possibilities for crafting immersive and interactive interfaces are endless.

In this step-by-step manual, we'll explore the fusion of 

 and Unreal Engine, empowering you to bring your UI ideas to life with ease.

Step 1. Set up the Web Browser plugin in Unreal Engine

Step 2. Create a new User Interface widget

Step 3. Add the Web Browser to your widget

Step 5. Create a Blueprint to display the widget

Step 6. Add the UI widget to the Blueprint

Step 7. Test your ProtoPie prototype in Unreal Engine

Begin by setting up the web browser plugin in Unreal Engine.

2. Go to the "Edit" menu, then select "Plugins.”

3. Search for the "Web Browser" plugin In the Plugins window.

4. Enable the Web Browser plugin if it is not already enabled.

 5. Restart Unreal Engine to apply the changes.

Create a new User Interface widget after setting up the web browser plugin.

1. Go to the "Content Browser" in Unreal Engine.

2. Right-click in the content area and select "User Interface," then "Widget Blueprint" to create a new widget.

3. Select “User Widget” and name your widget appropriately.

For the next step, you must include the web browser in your widget.

1. Open the Widget Blueprint you just created by double-clicking it.

2. A new window will open; you can click and drag this window to the main tab.

3. In the Designer tab, search for the "Web Browser" widget in the left Palette panel under “Experimental.”

 4. Drag and drop the Web Browser widget into your widget layout.

5. Resize (drag the double arrows) and position the Web Browser widget to fit your design.

You will set up the web browser widget by copying and pasting the URL of the ProtoPie prototype into it.

1. With the Web Browser widget selected, go to the Details panel.

2. Find the "Initial URL" property. Here, you will enter the URL where your ProtoPie prototype is hosted.

3. Launch ProtoPie Connect and import your prototype, selecting either from the Cloud (

) or uploading a local Pie file. Check your network settings and permissions to avoid connectivity issues when loading prototypes from the Cloud. 

4. Click the web browser icon to open the Pie in a browser.

5. If your Pie has a transparent background, add “&bg=transparent” at the end of the URL.

Tips & Tricks

Learn Fast with our Simple Pies Series: Build Interactive Prototypes Easily

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