This is the documentation for the latest (main) development branch of Zephyr. If you are looking for the documentation of previous releases, use the drop-down menu on the left and select the desired version.



The Freedom development board platform supports the MCR20A 2.4GHZ wireless transceiver. The FRDM-CR20A evaluation board is a small, low-power, cost-effective reference design for the MCR20A transceiver in a shield form factor, compatible with existing Freedom development platforms, such as NXP FRDM-K64F.




    • Low-power

    • High-performance 2.4 GHz IEEE 802.15.4 compliant transceiver

  • Connectivity

    • PCB inverted F-type antenna and SMA RF port

    • Arduino compatible

  • Power Management

    • Programmable output power -32 dBm to +8 dBm at the SMA connector, no trap

    • Receiver sensitivity: –102 dBm, typical

  • Components

    • Minimum number of matching components and external balun

    • 1 RGB LED indicator

    • 2 pushbutton switches

For more information about the MCR20A SoC and FRDM-CR20A board:


Set -DSHIELD=frdm_cr20a when you invoke west build. For example:

# From the root of the zephyr repository
west build -b frdm_k64f samples/net/wpanusb -- -DSHIELD=frdm_cr20a