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homechevron_rightDocschevron_rightDatasheetschevron_rightNotecard Datasheet - NOTE-WIFI

Blues Notecard® Datasheet: NOTE-WIFI

Wi-Fi Device-to-Cloud Data Pump

For developers looking for the ability to expand their wireless connectivity options beyond cellular without sacrificing the simplicity and power of the Notecard.

The Notecard WiFi is a version of the Blues Notecard dedicated for use on Wi-Fi networks only. The device follows the same m.2 pinout as the cellular Notecards. What's more, the Notecard WiFi uses the same powerful JSON-based programming interface, meaning that developers can easily add Wi-Fi as a deployment option for their IoT solutions, with minimal impact to their existing host applications.

warning

While this product is still supported, it is no longer available for purchase from the Blues store. We recommend the Notecard WiFi v2 as an updated, equivalent alternative.

Functional Description

As an embeddable device-to-cloud data pump, the Notecard eliminates all complexity and friction that exists with existing IoT solutions. It enables development and rapid iteration of production-quality secure cellular, Wi-Fi, or LoRa IoT solutions at an extremely low, fixed cost. With as little as two lines of code on the controlling MCU, and with no external libraries or dependencies, data can be sent from device to cloud.

Notecard is:

  • A drop-in embeddable data storage and transport module for Wi-Fi IoT products, pumping JSON-formatted or binary data ("Notes") bi-directionally between device and cloud:
    • JSON from/to MCU application using I2C, Serial, or USB.
    • JSON to/from your cloud app using HTTPS or MQTT.
    • JSON is auto-tagged with date/time.
  • A removable and field-upgradable 30mm x 35mm system-on-a-module (SOM).

Features

  • Low-power. Designed to operate on battery power, be "always-on", maintain time & location, while typically drawing less than ~12µA@5V when idle.
  • MCU-agnostic. Will support any MCU or single-board computer as your app processor - even low-memory, 8-bit microcontrollers.
  • Secure. Integrated STSAFE Secure Element with hardware crypto, true hardware random number generator, and a factory-installed ECC P-384 certificate provisioned at chip manufacture.
  • Simple. Uses a JSON command interface over I2C, UART, or USB. Allows you to connect your 3.3V MCU.
  • Power-conscious. Mostly-offline data sync mode for low power, and always-online mode for low latency.
  • Efficient. Battery-powered Wi-Fi without the complexity of managing connections, queues, or storage.
  • Integrated. Utilizes an extremely thin cloud infrastructure that directly routes your data to where it belongs: AWS, Azure, GCP, or your own cloud.
  • Built for data. Data routing and simple "no code/low code" visual data stream analysis through Notehub.io (SaaS), or host and integrate Notehub functionality into your own app (OSS).
warning

The performance of the STM32 microcontroller onboard the Notecard may be affected in the presence of extremely bright light including, for example, direct sunlight. Bright light may interfere with the semiconductor's operation by generating unwelcome electrical currents, performance degradation, malfunction, or shutdown.

If you anticipate that bright light may shine on your Notecard in its deployed setting, we recommend you mount the Notecard in a shadow, or that you cover the STM32 microcontroller with an opaque tape to reduce light levels that may affect the semiconductor.

Package Configuration

NOTE-WIFI

  • Product Name: Notecard WiFi v1
  • Module: Silicon Labs WFM200S Wi-Fi Transceiver Module
  • Radio: 2.4 GHz 802.11b/g/n

View in Store

Module Datasheet

  • Silicon labs WFM200S

Block Diagram

The Notecard WiFi is packaged using a compact removable form factor, 30mm x 35mm.

Open hardware schematics for both the Notecard and Notecarrier boards are available on GitHub , making it a straightforward task to embed the Notecard into a broad variety of host device designs.

The Notecard can interface with the host MCU at 3.3v levels.

Block diagram of Notecard WiFi v1

Typical Application

As shown below, Notecard is not an application processor and hosts no customer application code. It can be used as a data pump peripheral that is focused on bidirectional, asynchronous, secure data staging and transfer of JSON Notes.

Typical hardware configuration diagram

Key Features

  • Security

    Modern services require that the cloud and the device perform bidirectional authentication so that neither can be spoofed. For many applications it's important that over-the-air and over-the-wire data is encrypted. For this reason, the Notecard integrates an STSAFE Secure Element which contains symmetric keys manufactured into the chip. Neither the manufacturer of the Notecard nor the manufacturer of the customer's product has any need to handle or manage secure key material. The keys generated by STMicroelectronics for the Notecard use ECC with the NIST P-384 curve, and the signature algorithm is ECDSA-with-SHA384.

  • Low Power Consumption

    The Notecard has sophisticated power control and makes heavy use of variable clock speeds. This enables the Notecard to have a typical idle current consumption of ~12µA@5V, while still supporting active UART and I2C communication.

Power Information

The Notecard's main supply voltage (VMODEM_P) is used for the Wi-Fi radio and associated circuitry. The Notecard has on-board regulators designed for direct connection to a battery, so any voltage in the range of 2.5V to 5.5V may be provided.

The Notecard WiFi typically sits in an ~12µA@5V idle mode waiting for a request from the host MCU, however the Notecard current draw increases to about 80mA@5V when the Wi-Fi radio is active. The module also draws 10's of mA when the CPU is performing session encryption. As such, it's recommended that VMODEM_P be directly connected to a battery or other supply that is capable of such brief spikes. It is also recommended that PCB traces for VMODEM_P and GND be designed to handle such current.

The Notecard's logic voltage (VIO_P) is provided by the Notecarrier or host system for digital communication; it will be 3.3V. Although the Notecard typically draws very little current, this supply should be designed with a 150mA budget allocated to the Notecard.

Pin NameDirectionPin NumbersUsage
GND--3,5,6,11,18,33,39,45,51,57,71,73Ground
VIO_PIN2,43.3V @ 150mA
VUSBIN13USB Serial proxy for "line power", with respect to dynamic line voltage detection
VMODEM_PIN70,72,742.5V to 5.5V, capable of sustained 250mA draw
note

In order to take advantage of various Notecard features pertaining to "dynamic line voltage detection" (both now and in the future), or establish a USB Serial connection to the Notecard, you must connect the VUSB power pin and support the USB power design aspects of the Notecard.

Features include:

  • Continuous mode behavior with the usb flag.
  • Triangulate mode behavior with the usb flag.
  • Monitor mode behavior.
warning

Reset and Loss of Power

The modems from all manufacturers used on all Notecard variants are designed to be robust in the condition of a sudden loss of power or reset. That said, there is a very small chance of corruption in the flash file system of the modem on loss of power at VMODEM_P.

In addition, while Notecard itself also utilizes a wear-leveling flash filesystem designed to be resilient to a sudden loss of power, there is a very small chance of filesystem corruption on loss of power to VIO_P.

Upon sudden loss of power at VIO_P or upon any reset with NRST and once power is restored, Notecard will initiate a procedure to ensure filesystem integrity. Notecard will also conduct a procedure upon first connection to Notehub after power loss to ensure consistency between Notecard's flash filesystem and Notehub's replica copy of those files.

All of the above, when taken together, mean that hardware designs utilizing Notecard should provide constant power to VMODEM_P and VIO_P and should make diligent efforts to ensure that power failures and resets do not occur frequently and as a matter of course in the design of the product. Failure to do so will result in an increase in cellular data used and additional wear on the flash filesystem over time.

Antenna Requirements

The radio on the Notecard WiFi has an embedded antenna, though an external antenna can be used when connected through the u.FL connector on the Notecard. Any external antenna must support a 2.4 GHz frequency band.

The antenna included on the Notecarrier A series, as well as the external antenna provided with the Notecarrier Pi, support 2.4 GHz and have been tested with the Notecard.

Cellular Service

This section does not apply to the Notecard WiFi.

Pin Information

Pin Definitions

Pin NamePin Description
ATTN_PAttention pin (requires protection)
AUX_EN_PAuxiliary serial port enable (requires protection)
AUX_RX_PAuxiliary UART receive (requires protection)
AUX_TX_PAuxiliary UART transmit (requires protection)
AUX1Auxiliary GPIO pin 1
AUX2Auxiliary GPIO pin 2
AUX3Auxiliary GPIO pin 3
AUX4Auxiliary GPIO pin 4
AUX_CHARGINGCharge detection
GNDGround
NCNo connection (reserved and must be left open)
NRSTActive-low (not) reset*
RX_PUART receive (requires protection - Notecard has onboard 10K pull-up resistors)
SCL_PI2C clock (requires protection - Notecard has onboard 10K pull-up resistors)
SDA_PI2C data (requires protection - Notecard has onboard 10K pull-up resistors)
TX_PUART transmit (requires protection)
USB_DNUSB data negative
USB_DPUSB data positive
VIO_PI/O Voltage (requires protection)*
VMODEM_PVoltage modem (requires protection)*
VUSBUSB Active indicator from 3V3 to 5V

* See the power information section for important product design considerations related to reset and loss of power conditions.

Pin Description

Notecard M.2 Key E, Edge Connector Pinout

Pin #Pin NameFunc. InterfaceFunc. InterfacePin NamePin #
1NCPowerVIO_P2
3GNDPowerPowerVIO_P4
5GNDPowerPowerGND6
7USB_DPUSB SerialNC8
9USB_DNUSB SerialNC10
11GNDPowerNC12
13VUSBUSB SerialNC14
15NCNC16
17NCPowerGND18
19NCNC20
21NCNC22
23NCMODULE KEY--24
25--MODULE KEYMODULE KEY--26
27--MODULE KEYMODULE KEY--28
29--MODULE KEYMODULE KEY--30
31--MODULE KEYNC32
33GNDPowerNC34
35NCNC36
37NCAuxiliary PortsAUX_CHARGING38
39GNDPowerI2C SerialSCL_P40
41NCI2C SerialSDA_P42
43NCNC44
45GNDPowerAuxiliary PortsAUX146
47NCAuxiliary PortsAUX248
49NCAuxiliary PortsAUX350
51GNDPowerAuxiliary PortsAUX452
53NCAttentionATTN_P54
55NCAuxiliary PortsAUX_EN_P56
57GNDPowerAuxiliary PortsAUX_RX_P58
59NCAuxiliary PortsAUX_TX_P60
61NCUART SerialRX_P62
63NCUART SerialTX_P64
65NCNC66
67NRSTResetNC68
69NCPowerVMODEM_P70
71GNDPowerPowerVMODEM_P72
73GNDPowerPowerVMODEM_P74
75NC

Link: Digi-Key part number of the connector - Both Digi-Key and Mouser have pictures for this part number that show a component with a different key, but both have links to datasheet/drawing/CAD models.

note

All pins whose Functional Interface is marked "Power" must be connected.

All pins named NC MUST have no connection and be left open because they are reserved for future use. Furthermore, any pin not used in a design MUST also be left open.

Those pins ending with _P may be optionally protected from anomalous external conditions on some Notecarrier designs, depending upon use-case specific requirements.

Technical Details

Host Microcontroller API

Notecard supports a rich, simple API whose syntax is standard JSON. The developer can communicate requests to Notecard, generally by using little more than printf functions available in most programming languages.

Serial Communication

JSON requests and responses (the Notecard's Application Programming Interface "API") may be sent over any of the following interfaces:

  • USB Serial Interface
  • UART Serial Interface
  • I2C Interface
note

If NOT using a Notecard firmware library, you may unintentionally send requests to the Notecard so fast that you overflow the 1500 byte buffer used to receive data (whether it be I2C, Serial, or UART). The solution is to pause 250 ms after every 250 bytes sent and ensure the total size of each NDJSON object sent is no more than 8KB.

API Reference

For API usage, names, and parameters, please refer to the Notecard API Reference.

USB Serial Interface

The USB Serial Interface appears to the host as a USB 2.0 Full Speed CDC device. You can access it from Linux, Windows, or macOS without a device driver using terminal emulation software. Newline-delimited JSON requests may be sent directly as UTF-8 text over this port, or you may use the open-source Blues libraries for C, Python, Go, and Arduino.

Pin NameDirectionPin NumberUsage
USB_DMI/O9USB D- data signal
USB_DPI/O7USB D+ data signal
VUSBIN13+5V from USB
GNDI/O11Ground from USB
UART Serial Interface

The UART Serial Interface operates at VIO_P at a fixed baud rate of 9600 using eight data bits, no parity bit, and one stop bit. Newline-delimited JSON requests may be sent directly as UTF-8 text over this port, or you may use the open-source Blues libraries for C, Python, Go, and Arduino.

Pin NameDirectionPin NumberUsage
RX_PIN62Receive data signal
TX_POUT64Transmit data signal
I2C Interface

The Notecard acts as an I2C secondary device operating at VIO_P, and it implements a simple Serial-over-I2C protocol. You can access it from an embedded host using open-source Blues libraries for C, Python, Go, and Arduino.

Pin NameDirectionPin NumberUsage
SCL_PIN40I2C clock
SDA_PI/O42I2C data

Host Microcontroller Hardware Interface

Attention Interrupt

Using software, you can optionally configure Notecard to use the ATTN output pin to:

  • Inform the host MCU of certain asynchronous events (such as incoming data availability, or Notecard motion) in an interrupt-driven manner rather than just polling.
  • Place the host MCU into a power-off sleep state and wake it back up again.
Pin NameDirectionPin NumberUsage
ATTN_POUT54Attention pin
note

This pin operates at VIO_P. If it is unused it can be left disconnected.

Auxiliary Ports

An optional Auxiliary UART Serial Interface is available on the AUX_RX_P and AUX_TX_P pins. This interface is inactive unless enabled by raising the AUX_EN_P pin since this UART consumes extra power when in use. It operates at VIO_P at a fixed baud rate of 115200 using eight data bits, no parity bit, and one stop bit. If this interface is unused, the three pins can be left disconnected.

The AUX1-4 pins operate at VIO_P and can be configured in software to operate in several optional modes such as GPS Tracking Mode, GPIO Mode, and Internet Button Mode. If these pins are unused, they can be left disconnected.

Pin NameDirectionPin NumberUsage
AUX_EN_PIN56Enables serial port on AUX_RX_P and AUX_TX_P
AUX_RX_PIN58RX data for serial port enabled by AUX_EN_P
AUX_TX_POUT60TX data for serial port enabled by AUX_EN_P
AUX1I/O46General Purpose IO
AUX2I/O48General Purpose IO
AUX3I/O50General Purpose IO
AUX4I/O52General Purpose IO
AUX_CHARGINGI/O38Alt. attention pin or charge detection
note

The auxiliary serial port is normally disabled because it consumes up to 100µA of power when enabled.

Reset

Use of this pin is optional. If the host system has a global reset line, caution should be used when connecting this pin to the host system's reset because the Notecard may independently pull the line low in software. Restrictions on this pin are:

  • If this pin is not used, it must remain not connected (NC).
  • The pin is active-low. It must be held low for at least 350nS for a clean reset.
  • This pin must never be pulled-up. A pull-up would interfere with the Notecard's own internal watchdog timer and thus will prevent reliable operations.
  • Some Notecarriers may invert this signal to be active-high.
Pin NameDirectionPin NumberUsage
NRSTI/O67Active-low reset

Network Communication Behavior

The Notecard includes a built-in connection to Notehub.io (specifically a.notefile.net:8086) and communicates over SSL. Outbound connections speak directly with the Notehub session load balancer (or "Discovery Service") for provisioning and device authentication. By default, the TLS connection is unidirectional, but can operate bi-directionally, if needed. The keys and certificates for each device are provisioned by STMicrosystems inside the STSAFE secure element present on every Notecard. Once the Discovery Service has provisioned or authenticated a device, it issues a "ticket" and a Handler IP address that the Notecard can use to make subsequent requests.

The Notecard can also connect to the Handler to do a constrained set of remote procedure calls related to synchronization. If the Notecard determines that the data queued for transmission to or from the Handler should be encrypted, it opens a session to the Handler on port 8086. Otherwise, an unencrypted socket is opened on port 8081.

The over-the-wire data transmitted on both sockets is highly byte-optimized, which is why raw SSL and TCP sockets are used, and not unoptimized HTTP/HTTPS transactions.

Specifications

General Characteristics

DescriptionValue
Weight3 grams

Electrical Characteristics

Absolute Maximum Ratings

DescriptionMinimumMaximumUnit
Storage temperature-4090°C
Ambient operating temperature-4085°C

DC Characteristics

DescriptionMinimumMaximumUnit
Supply Voltage2.55.5V

Ordering Information

Blues Shop

Certifications

CertificationDate
CEPending
FCC: 47 CFR FCC Part 15, Subpart B, Class BFebruary 2022
RoHSPending

Board Errata

  • On units shipped where all large black capacitors indicate JJ8, the idle current of the notecard may measure slightly higher than the expected current draw indicated above.

Terms and Conditions

Visit Blues Hardware Terms & Conditions

Security and Vulnerability Scanning

As a part of our regular audit and scanning process, Blues Inc. performs full vulnerability scanning every six months. Any identified vulnerabilities will be analyzed, reported, and patched in a timely fashion, where appropriate.

Revision History

AuthorDateSummary
Ray Ozzie2019-2020Document drafted
John Wiedey2020Various improvements
Sean Taylor2020Various improvements
Zachary J. Fields11 SEP 2020Updated information and translated to markdown
Brandon Satrom13 APR 2021Updated Country list based on carrier audit
Carlton Henderson12 JUL 2021Update coverage information
Carlton Henderson12 JUL 2021Fix block diagram photo
Brandon Satrom11 NOV 2021Added Certification Dates
Brandon Satrom07 JAN 2022Added RoHS Certification Dates
Brandon Satrom15 FEB 2022Add Wi-Fi Notecard Datasheet
Rob Lauer25 AUG 2022Added updated certification data
Rob Lauer27 OCT 2022Update country coverage information
Rob Lauer13 JAN 2023Added RF performance information
Rob Lauer2 FEB 2023Warning re: STM32 light sensitivity
Kimball Johnson21 SEP 2023Updated for new Cell+WiFi, LoRa, and Wi-Fi Notecards
Rob Lauer23 OCT 2023Update and clarify power consumption values
Rob Lauer31 JAN 2023Update Notecard for LoRa datasheet details
Rob Lauer16 APR 2024Updated for new Cellular (black PCB) Notecards, MB Cellular Notecards, and Notecard XP
Rob Lauer6 JUN 2024Added cell band support for Cellular Notecards
Rob Lauer23 JUL 2024Update pin definitions
TJ VanToll24 SEP 2024Adding Notecard for LoRa v2.1 information
Rob Lauer01 NOV 2024Adding Notecard for LoRa v2.1 castellated pin info
Rob Lauer06 NOV 2024Added errata for Notecard Cell+WiFi
Brandon Satrom06 DEC 2024Expanded reset and loss of power guidance
Rob Lauer20 DEC 2024Added PTCRB certifications for WBNAN, NBNAN, NBGLN
Rob Lauer5 MAR 2025Update AUX5 to AUX_CHARGING

Contact Information

Blues Inc.
https://blues.com
50 Dunham Ridge Suite 1650
Beverly, MA 01915
support@blues.com

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