T-Mobile recently launched their first developer kit designed to speed up the development of IoT applications that require “transmitting small amounts of data over long periods of time.” The DevEdge is powered by a Cortex-M4 processor, wireless connectivity, diverse sensors and it runs on a Zephyr-based SDK.

According to the datasheet, the DevEdge Dev Kit is built around the 32-bit EFM32 Pearl Gecko microcontroller.

• SiLabs EFM32 Pearl Gecko   — Arm Cortex-M4 (up to 40MHz); Up to 1024 kB Flash, 256kB RAM;64 μA/MHz in Active Mode, 2.1 μA sleep w/ RTC & RAM retention

     
DevEdge block diagram (left) and rear view (right)
(click images to enlarge)

For connectivity, this dev kit integrates a 4G LTE CAT-M module (up to 375 Kbps) that supports GPS and GLONASS. The board also supports 2.4GHz Wi-Fi/BLE 5.0 via a RS9116W from SiLabs.  

The product page mentions that the DevEdge kit is “automatically connected to the T-Mobile network through a SIM card preloaded with 500MB of data.” Apparently, T-Mobile also includes a SMS Notification API which includes up to a 1000 messages free for a year and a Location API to access the location of the DevEdge. 

 
DevEdge app (left), tmo_shell (center) and services available (right)(click images to enlarge)

Besides the sensors mentioned on the specification list, the board also includes a battery charger with power path management, a battery monitor/fuel gauge and a Real-Time Clock. The datasheet of this product can be found using this link. 

For software development, T-Mobile is providing a Zephyr RTOS based application to test the capabilities of the DevEdge IoT Dev Kit. The Getting Started Guide can be found using this link. Code samples and drivers can be found on the DevEdge IoT GitHub.

        
DevEdge exploded view (left) and front view (right)(click images to enlarge)

The company also mentioned that “users are free to use their software and hardware designs to develop their own products.” 

Specifications listed for the DevEdge IoT Dev Kit include:

• Storage:
  • 8MB external FLASH (Winbond W25Q64)
• Connectivity:
  • LTE CAT-M Module (Murata 1SC)
  • 2.4GHz Wi-Fi (SiLabs RS9116W)
  • BLE Bluetooth 5.0 (SiLabs RS9116W)
• USB:
  • 1x Type-C USB connector
• I/O Peripherals:
  • RGB LED (Kingbright APFA3010)
  • White LED (Inolux IN-S63AS)
  • Temperature sensor (AMS AS6212)
  • Accelerometer (STMicro LIS2DW12)
  • Ambient light sensor (AMS TSL25403)
  • Pressure sensor (STMicro LPS22HHTP)
  • Buzzer (PAM8904E)
• Debugging:
  • Segger J-Link programming interface (NXP MK22FN128VMP10)
• Other Features:
  • QWIIC I2C expansion connector
  • Lithium Ion Battery (PHD Energy 603033)
• Software:
  •  Zephyr SDK/tmo_shell

Further information

T-Mobile has launched the DevEdge IoT Developer Kit for $99 which includes the board, a protective case, a USB-C to USB-A cable, a SIM card and a USB-A power adapter. See the product page for additional information.