Challenger+ RP2350 NB-IoT is a Feather-compatible board pairing a Raspberry Pi RP2350 microcontroller and a certified NB-IoT cellular module with built-in GNSS, suitable for long-range, low-power connectivity.
It looks to be a variant of the earlier Challenger+ RP2350 WiFi6/BLE5 board that replaces an ESP32-C6 WiFi 6, BLE, and 802.15.4 module with an STMicroelectronics ST87M01 NB-IoT and GNSS module. It still offers
Challenger+ RP2350 NB-IoT specifications:
- Microcontroller – Raspberry Pi RP2350A MCU
- CPU
- Dual-core Arm Cortex-M33 processor @ 150MHz
- Dual-core 32-bit RISC-V processor @ 150MHz
- Up to two cores can be used at a given time
- Memory – 520KB internal RAM
- 8KB OTP Storage
- Package – QFN-60; 7×7 mm
- CPU
- Memory – 8MB PSRAM
- Storage – 8MB SPI flash
- Cellular connectivity
- Module – STMicro ST87M01-1301
- LTE Cat NB2 (NB-IoT), 3GPP Release 15
- Worldwide regional bands coverage – B1, B3, B5, B8, B20, and B28
- Single-tone / Multi-tone / Extended TBS and 2 HARQ
- Data rate – Up to DL: 127 kbps, UL: 159 kbps
- Up to +23 dBm power output
- Low power
- eDRX and PSM support
- Sleep current of 1.2 µA (PSM), dropping to 0.5 µA in power-off mode (eDRX)
- Location
- GPS L1 and Galileo
- Assisted GNSS available over the NB-IoT link for fast first fix.
- Wi-Fi positioning via 802.11b access point scanning for indoor location fallback
- Package – 12.8 x 10.6 mm (LGA-51)
- Nano SIM card slot; optional 1NCE IoT SIM card with 500 MB data, 250 SMS
- Antennas – 2x IPEX connectors for cellular and GNSS antennas
- Module – STMicro ST87M01-1301
- USB – USB 1.1 Type-C (12 Mbps) port for power, data, and programming
- Expansion
- 16-pin + 12-pin headers
- Up to 20x GPIO
- 1x SPI, 1x I2C, 1x UART
- 4x analog inputs
- All pins can be used as PWM
- Reset and Enable signals
- VUSB (5V), 3.3V, VBAT, and GND
- 2x BConnect connectors: 1x I2C, 1x SWD + UART
- 16-pin + 12-pin headers
- Misc
- Reset and Boot buttons
- Charging LED, user LED
- Power Supply
- 5V via USB-C port or VUSB pin
- 1.25mm pitch JST connector for 3.7V LiPo battery
- Onboard LiPo charger with 500mA standard charge current
- Dimensions – 50.8 x 22.9 (Adafruit Feather form factor)
- Weight – 9 grams
- Certifications – GCF, RED (EU), RED-DA, RoHS
The Challenger+ RP2350 NB-IoT board can be programmed with the Arduino IDE and CircuitPython, but it also supports the Raspberry Pi Pico C and MicroPython SDK. Firmware updates are supported both over-the-air via Differential FOTA over LwM2M and locally over UART. Code samples are coming soon, and you can find work-in-progress documentation for the Challenger+ RP2350 NB-IoT board itself and the STM87M01 NB-IoT module in particular on the product page/store linked at the end of this article.
Target applications include asset tracking and logistics, smart metering (water, gas, electricity), Smart City infrastructure (e.g., street lighting control), Industrial IoT monitoring and factory automation, environmental sensing with long-interval reporting, and remote alarm and event notification systems. It’s the first RP2350 board with NB-IoT connectivity I’ve seen, and the closest alternative I can think of is the Walter ESP32-S3 board with a Sequans GM02SP NB-IoT & GNSS modem.
The Challenger+ RP2350 NB-IoT board is sold for 549 Swedish Kronas, or about $60 US, on the iLABs store. As I understand it, the antenna is not included, but you can add an LTE antenna for 68 kr (~$7.5 US). I’m less clear about the GPS antenna, and it appears you are expected to source your own.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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