LimiFrog: matchbox-sized battery-powered sensor-filled dev platform, on Kickstarter

Posted on 2015/09/10


Disclosure: I am currently employed by STMicroelectronics. The product I’ll be talking about contains many ST chips and the creator was an ST employee himself. I’ll be writing my own personal opinions, you can judge if they are biased.

I received news about this Kickstarter: LimiFrog. It’s a small board advertised for developing and prototyping applications that needs sensors and connectivity. I think it’s remarkable because it’s very compact, promises to be energy efficient and has so many features to rival an Arduino plus something like four shields (battery, bluetooth, display, sensors).



Its full-featured version has:

  • An STM32L4 that contains:
    • ARM Cortex-M4 microcontroller with Floating Point Unit
    • 80MHz of CPU clock speed
    • 512KiB of embedded flash and 128KiB of RAM
    • Many peripheral controllers
  • An OLED display
  • A LiPo battery that can be recharged with USB
  • 8 Megabytes of non-volatile flash memory
  • A boatload of sensors: accel, gyro, pressure, ambient light, a mic, temperature, magnetometer, proximity.
  • Bluetooth 4.1 Low Energy
  • Connector for extensions like UART, SPI, A/D, …

The creators are developing code (it’s public on their GitHub repository) based on CMSIS and STM32 peripheral library. It contains the code to treat the 8MiB flash as a FAT-formatted disk, and a graphic library for the OLED display. They have plans to port micropython to the platform so that it can be programmed also in (a subset of) Python. It’s possible to upload code via USB and connect with a debugger via an SWD connector (needs an adapter, I bet something like an FTDI cable would work too).

The Kickstarter objective is to start production of a large batch of boards, so that the costs can be brought down and the final price can be competitive. The end date is at end of September.

Posted in: Hardware