Conexio Stratus is a tiny (50.8 mm x 22.86 mm) yet powerful development kit for creating cellular-connected electronic projects. It runs best-in-class Zephyr RTOS for connected devices and is a battery-operated platform, making it ideal for prototyping cellular IoT systems such as asset-tracking applications, environmental monitoring, and smart-meter monitoring, just to name a few.

Equipped with the Nordic nRF9160 System in Package (SiP), it supports LTE-M, NB-IoT, and Global Positioning System (GPS). Stratus has two onboard external U.FL antennas, one for the GPS and the other for LTE-M/NB-IoT, enabling it to support a global range of LTE bands.

Built-In Battery Charging, Monitoring, and Energy-Harvesting

Stratus has built-in battery charging, monitoring, and energy-harvesting circuitry that makes it easier to connect to and recharge the Li-Po battery, creating fully energy-autonomous applications. In addition, Stratus incorporates an accelerometer and a temperature-and-humidity sensor for detecting movement and for sensing its surrounding environment. Finally, Stratus provides 26 mixed-signal GPIOs for interfacing with external sensors, actuators, and other electronics.

Prepaid Data and SMS

To connect to IoT cellular networks out-of-the-box, Stratus comes with 500 MB of mobile data and a total of 250 SMS messages, valid for 10 years with service in more than 100 countries worldwide without additional costs, making it the most versatile IoT-development kit on the market.

Useful From Smart Homes To Smart Industry

Stratus is perfect for connecting existing projects to the Cloud or as a gateway to connect other local endpoints without having to worry about the infrastructure cost, making it useful for both professionals and hobbyists.

For example: Stratus is perfect for environmental monitoring and smart agriculture like precision farming, crop monitoring, climate and food supply-chain monitoring, and farm analytics. It’s also excellent for smart energy and utilities, and can ​​enable smart grids, smart metering, and remote diagnostics for easy monitoring and billing. You could use Stratus for fleet management, to ​​track your assets in real-time with seamless global coverage and end-to-end visibility, or for machine monitoring to enable predictive maintenance via cellular connectivity for Industry 4.0 applications. Stratus can be used in retail deployments, for smart checkout or supply chain management, or in the healthcare sector, to power mission-critical applications like remote patient monitoring and wearables.

Conexio Stratus also supports platforms like Edge Impulse, Memfault, and Golioth, leveraging machine learning (ML) to provide seamless Over-the-Air (OTA) updates to your devices. ML capabilities are extremely helpful in implementing predictive maintenance in scenarios where uninterrupted operation is particularly important, such as in smart factories. For easy data visualization and dashboard creation, Conexio Stratus also connects to Datacake, a low-code IoT platform that requires no programming.

Pinout

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Features & Specifications

MCU: Nordic nRF9160 Microcontroller with ARM Cortex M33

• 1 MB Flash
• 256 kB RAM
• ARM® TrustZone®
• ARM® Cryptocell 310
• Up to 4x SPI, I²C, and UART with Easy DMA
• I²S w/ EasyDMA
• 4x PWM with EasyDMA
• 12 bit SADC with EasyDMA
• 2x RTC
• PPI (Programmable peripheral interconnect) interface

Modem

• Transceiver and baseband
• 3GPP LTE release 13 Category M1 and NB1 compliant
• 3GPP release 14 NB2 compliant
• GPS receiver (GPS L1 C/A supported) - Active antenna only.
• RF Transceiver for global coverage supporting bands:
• Cat-M1: B1, B2, B3, B4, B5, B8, B12, B13, B14, B17, B18, B19, B20, B25, B26, B28, B66
• Cat-NB1/NB2: B1, B2, B3, B4, B5, B8, B12, B13, B17, B18, B20, B25, B26, B28, B66
• Supports 4FF Nano SIM
• Pre-programmed MCUBoot bootloader

Micro USB

• For USB-to-Serial, DFU, and application firmware programming and debugging plus LiPo battery charging

Energy harvester IC

• AEM10941 solar energy harvester from E-peas Semiconductors
• Vin: 50 mV to 5 V
• Cold start: 3 μW @ 380 mV
• Power input: 3 μW to 550 mW
• Maximum power point tracking (MPPT)
• Supports battery types Li-ion and NiMH
• Max solar panels: up to 7 solar cells simultaneously

Board power supply

• 3.3 V Buck/Boost up to 0.9 A of current draw
• Operating range 2.8 to 5.5 V
• External LiPo battery connection (2 Pin JST type)
• Charge rate set to 300 mA with yellow LED indication
• Maximum output current: 800 mA
• Current consumption in low-power-mode: < 5 μA

Debugger & Programmer

• Supports J-Link and CMSIS-DAP based programmers
• 10-pin 0.05" (1.27 mm) pin connector

User I/O

• 32 Standard GPIOs (0.1" pitch)
• 26 user-programmable GPIOs
• 2 x push buttons (1 Reset, 1 General Purpose connected to P0.12)
• 1 x user-programmable Green LED connected to D7 (P0.03)

Antenna connections

• 1 x U.FL for LTE-M/NB-IoT with matching network
• 1 x U.FL for active GPS antenna

Onboard sensors

• Latest SHT4x temperature and humidity sensor from Sensirion
• ST Microelectronics LIS2DH MEMS digital output motion sensor: ultra-low-power high-performance 3-axis Femto accelerometer

Power switch

• SPDT slide switch for turning ON/OFF the power to the Stratus board

Physical

• 50.8 mm x 22.86 mm (2.0" x 0.9")
• Weight: ~5 grams.

Conexio Stratus Shield

For expansion and interfacing with various sensors and hardware peripherals via standard interfaces (I²C, SPI, and UART), Conexio Stratus also comes with a shield as an optional add-on. Working with a Stratus shield requires no soldering and minimal wiring. Just plug the sensors, actuators, or displays into this shield using standard cables and stay focused on application design and coding.

Stratus Shield Features & Specifications

• 1x mikroBUS connector: an add-on board standard from MikroE that provides access to over 800+ click boards
• 2x SparkFun Qwiic connector: allows access to over 100+ Qwiic products
• 1x Grove I²C connector: a modular, standardized connector-prototyping system by Seeed Studio
• 1x 2-pin JST connector for solar-panel input
• 1x user-programmable LED
• 3.3 V operating voltage

Compatible with over 800+ sensor modules

Conexio Stratus is compatible with over 800+ sensor modules and boards from providers like Sparkfun, Mikroe, and Seeedstudio. This gives developers the ability to utilize a large array of sensor libraries, and extends the capabilities of Conexio Stratus to accelerate your IoT application testing and development.

Conexio Studio

Conexio Studio is a tool that allows you to create and debug Conexio Stratus + Zephyr RTOS projects in Visual Studio Code. To make application and project development fast and fun—for low-level application designers and novice IoT developers alike—the Conexio team has developed an extension for Visual Studio Code. Using Conexio Studio, you can build, compile, and deploy code to Conexio Stratus with minimal effort. Create projects with nRF Connect SDK and Zephyr RTOS with built-in templates created by the Conexio team. All examples and the VSCode extension will be available for download when the campaign begins.

Comparisons

Support & Documentation

Once the campaign is fully funded, we will publish our open source files on GitHub. That will include our schematics, firmware project files, documentation, and software:

• Board schematics
• Firmware
• Software
• Tutorials

User documentation links will be made available as the campaign progresses, and we welcome questions and discussion in the Conexio Discord channel.

Manufacturing Plan

Stratus hardware has been refined gradually over three pre-production revisions. The latest revision has been thoroughly validated and is already being used by a number of pre-production testers and open-source contributors. Each board will be tested prior to shipment to our backers. We have developed working relationships with several contract manufacturers in China, and we trust them to manufacture and assemble Stratus electronics. We are working closely with a number of distributors and vendors—including Nordic Semiconductor, who designed the main nRF9160 SiP module, E-Peas Semiconductors, who makes the AEM10941 energy harvesting PMIC, and Symmetry Electronics, to accelerate component acquisition so that we can manufacture Conexio Stratus as quickly as possible under current supply-chain conditions. We expect the first batch of Conexio Stratus to ship to our backers by May of 2022. As always, we’ll keep you up to date on manufacturing developments as they occur! Updates will be posted to the Conexio Discord Channel, posted as Crowd Supply campaign updates, and sent via email to campaign subscribers.

Fulfillment & Logistics

After the Conexio Stratus hardware is manufactured and tested, it will be sent to Crowd Supply’s fulfillment partner, Mouser Electronics, who will distribute it to the backers worldwide. You can learn more about Crowd Supply’s fulfillment service under Ordering, Paying, and Shipping in their guide.

Risks & Challenges

The global electronics supply chain is experiencing an unprecedented chip shortage that makes it significantly more difficult to get concrete estimates about manufacturing timelines. While we are confident in our ability to produce Stratus, industry-wide uncertainty regarding component lead times means that there’s a non-negligible risk of delivery delays.

To reduce the effects of the chip shortage as much as possible, we’ve been working directly with our suppliers, manufacturers, and critical-component vendors to acquire the necessary components as soon as possible. We’ve made arrangements to ensure the manufacturing process will start as soon as possible once all necessary components are on hand.