Prototype Planning Checklist
A prototype is neither a finished design, nor a pilot program for your first customers. Instead, prototyping a smart connected product proves that your idea is technically viable and capable of delivering real business impact. Through focused, iterative prototypes you'll confirm that your core concept works — that user behavior, data volume, and latency needs can be reliably met under real-world conditions.
This guide outlines how to approach prototyping with an actionable checklist of items that need to be considered. Ideally, the result is a series of quick, focused prototypes — each one proving (or disproving) your riskiest assumptions first — that together build the confidence you need to move into the pilot stage.
However, it's important to remember that even a prototype that doesn't succeed is valuable! As long as you record the outcomes, every prototype moves you forward, either by revealing exactly what to fix and re-test in the next iteration, or by giving you the confidence to redirect resources toward the next big idea.
Catching critical mistakes, omissions, and errors at the prototyping stage is far less costly than encountering problems during production.
noteKey Takeaways
- Prototyping is iterative — build quick, focused prototypes that prove (or disprove) your riskiest assumptions first, then move on to the next one
- Use realistic conditions: real RF technology, real environments, real power constraints
- Document everything — even prototypes that don't succeed provide valuable data for the next iteration
- The goal is to validate your hypothesis quickly and cheaply before committing to a pilot
In This Guide
This guide walks you through how to plan, build, and evaluate a connected product prototype:
- High-Level Product Prototyping Strategy: How to scope prototypes, define success criteria, and test with real technology.
- Considerations When Building a Prototype: Hardware, firmware, and cloud factors to validate during prototyping.
- Common Prototype Pitfalls: Mistakes that derail prototypes or lead to false confidence.
- Prototype Documentation: What to record so your learnings carry into the pilot phase.
- When is a Prototype "Done"?: A checklist to confirm you're ready to move forward.
High-Level Product Prototyping Strategy
Consider what must be true for this product to exist? At its core, a prototype must prove your device successfully executes its critical functions.
Start your prototype process by...
Getting input from as many potential customers, stakeholders, and experts as possible to ensure you know your must-haves, along with nice-to-haves that could make or break a project.
At the same time, use your experience and expertise as a filter. One product can't do everything. Taking every suggestion at face value can lead to overly complex designs, never-ending delays, and/or unused features.
Clearly define success, with a timeline for completion. A clear definition will avoid "scope creep," where further requirements are tacked on after the prototype's initialization. A completion timeline will help push the prototype past shifting priorities that could otherwise delay or sidetrack its completion.
Keep each prototype focused, but test with real technology. A prototype doesn't need to be complete — it needs to answer a specific question. But the answers are only trustworthy when you test with the actual RF technology you intend to ship (not a stand-in) and, where possible, in conditions that resemble the deployment environment. Blues makes this easy: grab a starter kit, connect to Notehub, and start testing your riskiest assumption in hours rather than weeks.
noteFor example, if you're building a product that will be deployed underground inside storm drains, your prototype should confirm which radio technology (cellular, satellite, LoRa, and/or WiFi) can reliably communicate from that environment. Validating coverage at every specific deployment location is a pilot-phase activity — but proving the radio technology works in representative conditions is a prototype concern.
Prototyping also generates early signals that strengthen your business case — but keep expectations realistic. A prototype is not a production design, so prototype costs won't match production costs. What a prototype can tell you is whether the core concept works, whether the technology is fit for the job, and whether any showstoppers exist that would change the economic picture. Use those signals directionally: to build confidence with stakeholders, refine your value hypothesis, or decide it's time to pivot.
noteThese questions aren't meant to dissuade you from prototyping, but rather get you thinking about potential roadblocks ahead of time!
Considerations When Building a Prototype
A successful prototype validates three interconnected layers: the physical device, the code that runs on it, and the cloud infrastructure that receives its data. Let's examine some potentially hidden considerations within all three.
- Hardware Prototyping Considerations
- Firmware Prototyping Considerations
- Cloud Prototyping Considerations
Hardware Prototyping Considerations
At its core, a smart connected device is a physical thing that exists and functions in the real world. Consider the following to make sure that its hardware and physical structure fulfills its must-have requirements:
Test real-world prototype functionality in as realistic of a scenario as possible, with the same instrumentation as the end product. Challenge your assumptions and look for issues that you may not have considered.
Data acquisition, data display, and/or actuation typically defines a smart connected device's fundamental purpose. If it doesn't execute on whatever it's supposed to do as a physical thing, it doesn't matter how well it uses the internet.
For example, if a remote temperature monitor doesn't sense the temperature to a usable precision and accuracy, then whether or not it sends this data to the cloud is immaterial.
Choose your communication methodology (e.g., cellular, satellite, LoRa, and/or WiFi) and planned antenna setup. Know that when you choose Blues, you're also choosing flexibility to deploy WiFi in location A and cellular in location B without changing your underlying code base.
noteFor example, consider a sensor setup that works underground inside a storm drain. A cellular connection may be considered, but will this actually work with the physical barriers that exist underground? Or maybe LoRaWAN or 2.4 ghz WiFi are better options, with potentially better penetration. The beauty of Blues is you can start with one radio and switch to others as your physical deployments evolve.
Since remote firmware updates are standard, be sure to test the process as part of your overall wireless strategy.
Test power sourcing and efficiency. When a device is designed to operate off-grid for months, or even years, power usage must be optimized, especially with regard to wireless data transmissions. Required throughput and latency must be tested versus power consumption. Planned battery, solar, or wired power supplies must be specified and tested in the prototyping phase to ensure they meet device demands.
noteTest physical size, shape, and accessibility constraints. Consider if the device is the appropriate physical size to facilitate installation and extraction. Can a technician physically reach programming ports and view indicators when in-service?
Even a simple blinking LED to indicate that your device is alive can be valuable for technicians in the field. Build in on-device feedback mechanisms as often as possible.
Ensure proper security, allowing the "good guys" to easily access your device, while malicious actors are physically and electronically "locked out" to whatever extent is appropriate.
noteBlues provides hardware-based security via a tamper-proof HSM (STSAFE), TLS encryption, and private cellular networks. See Blues Security, Reliability, and Governance for details on how Blues ensures security from prototype to production.
Beyond the core Notecard modules, Blues offers several devices that are well-suited for prototype validation. Blues Notecarriers — essentially development/carrier boards for Notecards — come in multiple configurations, including a model that mounts Adafruit Feather form factor devices, another that provides an onboard STM32 host, and another that acts as a Raspberry Pi HAT. The minimal X-series Notecarriers even work well for production/scaling deployments.
Firmware Prototyping Considerations
Next is the firmware, the code that runs on your device. Proper firmware is critical to device operation and uptime. Consider the following in your firmware design and prototyping phases:
Build remote configurability functions into the prototype's firmware, ideally using environment variables. Beyond environment variables, test making fundamental firmware changes and recovering a bricked device with Notecard Outboard Firmware Update.
Test data efficiency on a firmware level. Firmware should transmit the appropriate amount of data at a short enough interval to avoid latency issues. By using Blues Notecard, with its ample flash storage and templating features, you can store up to 1MB of data on each device before syncing. And the store-and-forward mechanism ensures data integrity from device to cloud.
Test firmware security by implementing critical systems and security architecture in the prototype phase. While the basic system architecture should be established early, firmware will continue to develop into the pilot programs and initial device launch. Testing should be ongoing through the product's lifecycle to combat emerging threats.
More information on data and device security with Blues is available here.
While firmware is certainly more flexible than hardware, it is better to have it tested and working properly in the prototyping phase than to revise it later under more stressful and/or costly conditions!
noteA more in-depth look at firmware development is available in our Firmware Best Practices Guide.
Cloud Prototyping Considerations
Data from smart connected devices has to go somewhere, typically via a cloud interface. Before establishing the cloud aspect of a project, consider several specific questions:
- What are the access and latency requirements?
- Do you plan to archive your data, and if so, where?
- How do you plan to access this data now and long term?
- How will you keep this data secure?
- Is there any data that is especially sensitive and needs additional consideration?
With those questions (and answers) in mind, the following considerations should be tested and validated:
Establish and test transport and security architectures. Blues hardware sends (and receives) encrypted data to (and from) the Blues cloud service Notehub. Notehub acts as your integration's cloud orchestration tool. Notehub routes data to and from cloud services like AWS, Azure, and GCP.
Examine cloud data efficiency, considering throughput, latency, and data transport and storage costs. Test cloud data usage in as realistic a manner as possible. Most importantly, validate that the data your device produces can actually drive the business outcomes you're targeting — whether that's preventing downtime, reducing truck rolls, saving energy, assuring safety, or preventing losses. Can the data reach the right people and systems fast enough to trigger the actions that create value?
noteA more in-depth look at cloud architecture planning is available in our Cloud Architecture Guide.
Similar to firmware prototyping, if these critical questions aren't answered in the prototyping stage, any corresponding challenges can't be tested until later in the product lifecycle. A simple change, made early in response to testing, could alleviate a very complicated cloud and/or firmware workaround later.
Prototyping gives you the opportunity to make changes while all options are still on the table!
Common Prototype Pitfalls
So that's a high-level look at numerous pre-prototype considerations. Next, let's look at avoiding common mistakes that can derail your prototyping efforts or lead to false confidence as you move to the pilot phase.
Testing in Unrealistic Conditions
The pitfall? Testing on your desk with a strong cellular connection instead of also testing in the field with scant cellular access.
Why does it matter? RF conditions, power availability, and environmental factors vary dramatically between lab and deployment.
The fix? Test in conditions as close to production as possible, including edge cases like weak signal, extreme temperatures, and power interruptions.
Skipping Power Budget Analysis
The pitfall? Assuming "we'll optimize power later" without measuring actual consumption.
Why does it matter? Power constraints often drive fundamental architecture decisions that are expensive to change later.
The fix? Measure power consumption early using tools like Blues Mojo, establishing a power budget and tracking it throughout the prototype phase.
Ignoring Edge Cases
The pitfall? Only testing the "happy path" where everything works as expected.
Why does it matter? Real-world deployments encounter network outages, sensor failures, and unexpected user behavior.
The fix? Deliberately test failure modes. What happens when connectivity is lost? When the battery dies mid-transmission? When a sensor returns invalid data?
Over-Engineering the Prototype
The pitfall? Building production-quality hardware and firmware before validating core assumptions.
Why does it matter? You may invest significant effort in features that don't matter or approaches that don't work.
The fix? Focus on validating your riskiest assumptions first, using off-the-shelf development boards like Blues Notecarriers to iterate quickly.
Poor Documentation of Learnings
The pitfall? Not recording test results, decisions, and learnings as you go.
Why does it matter? When you move to pilot, you (or your team) will need to remember why certain decisions were made.
The fix? Keep a prototype log documenting tests performed, results, and decisions made.
Prototype Documentation
As previously mentioned, maintaining good documentation during prototyping can save you significant time later. Be sure to record the following throughout the prototype process:
Test Log
For each test performed, document the date and conditions (including location, temperature, and RF environment), what was tested and why, expected vs. actual results, decisions made based on results, and follow-up actions identified.
Hardware Decisions
Record your BOM with part numbers and suppliers, schematic decisions and trade-offs considered, physical dimensions and enclosure requirements, and antenna selection rationale.
Firmware Decisions
Document your architecture overview (main loop, state machines, interrupt handlers), communication protocol with Notecard, data format and transmission frequency, and power management approach.
Cloud Architecture
Capture your Notehub project configuration, routing rules and downstream destinations, Note/event schema and expected event structure, and dashboard or data visualization approach.
This documentation will form the foundation of your pilot planning and help onboard additional team members.
When is a Prototype "Done"?
A prototype is ready for the next phase when you can answer "yes" to these questions:
- Core functionality validated: Does the device perform its primary functions reliably?
- Connectivity proven: Have you tested the actual RF technologies in realistic conditions?
- Power budget established: Have you measured (not estimated, measured!) power consumption data?
- Data pipeline working: Does data flow from device to Notehub to your cloud application?
- Critical edge cases tested: Have you verified behavior during connectivity loss, power interruption, and sensor failures?
- Security architecture defined: Is your approach to device authentication and data security established?
- BOM costs estimated: Do you have realistic cost estimates for pilot hardware?
- Timeline validated: Can you estimate the effort required for pilot and production phases?
If you're missing answers to any of these, continue iterating. If you have conflicting results or unresolved technical risks, consider whether the project should proceed at all. This is exactly what prototyping is designed to uncover!
Resources and Next Steps
With a prototype built and successfully tested, it's time to go on to the next phase, typically a pilot program with a limited number of customers. Ensure you record all the data that you've gained along the prototyping journey, allowing you to adjust pricing, labor, work instructions, and anything else that might be pertinent further on in the product's lifecycle.
If testing is not successful — or if it casts doubt on the ultimate project success — it may be time to re-evaluate. The device's operation and/or project goals may need to be changed so that another prototype can be tested. Or it may be better to shift focus to the next big thing. Even in this case, you've saved significant time and expense over developing a smart connected product that would ultimately be a dead end!
Blues Resources
Getting Help
If you have additional questions about planning a prototype for your Blues-based product:
- Post questions on the Blues Community Forum
- Contact Blues sales for enterprise-level support