LoRa module in DIL form

Murata produces LoRa module CMWX1ZZABZ-xxx based on SX1276 transceiver and STM32L072CZ microcontroller. The soldering of the LGA module is not very hobby-friendly. I constructed small breakout PCB for this module with additional buck/boost switcher and place for SMA connector. The transceiver features the LoRa®long-range modem, providing ultra-long-range spread spectrum communication and high interference immunity, minimizing current consumption. Since CMWX1ZZABZ-091 is an “open” module, it is possible to access all STM32L072 peripherals such as ADC, 16-bit timer, LP-UART, I2C, SPI and USB 2.0 FS (supporting BCD and LPM), which are not used internally by SX1276.

LoRa breakout board

 

Microcontroller features

  • CMWX1ZZABZ-091 LoRa® module with STM32L072CZ
  • ARM® 32-bit Cortex®-M0+ CPU
  • 32 MHz max CPU frequency
  • VDD from 1.65 V to 3.6 V
  • 192 KB Flash
  • 20 KB SRAM
  • GPIO (40) with external interrupt capability
  • General-purpose Timer (4)
  • Basic Timer (2)
  • Low Power Timer
  • SPI (6)
  • I2S
  • I2C (3)
  • USART (4)
  • Low-power UART
  • USB 2.0 full-speed
  • 12-bit ADC with 13 channels
  • 12-bit DAC (2) with 1 channel each
  • Comparators (2)
  • RTC
  • Capacitive sensing channels (19)
  • Random Generator (TRNG for HW entropy)

Board features

  • Dual-in-Line form factor with 100 mils pitch suitable for prototyping
  • On-board SWD connector
  • Flexible board power supply
    • external 3,3V source
    • External battery (single Li-xx cell or 2/3 LRxx cells)
  • On-board SMA connector and output RF filter

Board schematic and assembly drawing

Schematic is available here: https://github.com/s54mtb/lora_breakout/raw/master/hw/lorabreakout-sch.pdf

Assembly drawing

Gerber files and altium project

Files are here: https://github.com/s54mtb/lora_breakout/tree/master/hw

Board pinout

LoRa breakout board – pinout

GITHUB repository: https://github.com/s54mtb/lora_breakout

 

3 Comments

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  2. Guy says:

    Hey,

    FYI: if you want to use this with the STM32CubeExpansion_LRWAN library and get low power operation you need to drive the TCXO_VCC pin with a GPIO output. This way the oscillator can be powered down when the device is asleep. Without this you will be lucky to get below 1ma current. With this you should be able to get down to a couple of microamp. Although your regulator is a bit power hungry (50uA quiescent).

    How do I know ? I have made my own breakout too !

    Best regards

    Guy

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