RE: How to set the nRF21540-DK using basic sample (peripheral nus) with 20dBm TX power ?

Daewoong Kim — Fri, 03 Jul 2026 01:12:46 GMT

Thank you, Vidar

it works well 🙂

Best regards,

Daewoong Kim

RE: How to set the nRF21540-DK using basic sample (peripheral nus) with 20dBm TX power ?

Vidar Berg — Wed, 01 Jul 2026 12:31:34 GMT

Hello,

When you use the nrf21540 DK as your build target, it should be sufficient to add the following to your project configuration to achieve 20 dBM output power:

# Desired output power on antenna 
CONFIG_BT_CTLR_TX_PWR_ANTENNA=20
# Select POUTA (default: 20 dBm) for nRF21540 FEM TX gain
CONFIG_MPSL_FEM_NRF21540_TX_GAIN_DB=20

Setting CONFIG_BT_CTLR_TX_PWR_ANTENNA to 20 is necessary here. Otherwise, it defaults to 0 dBm, and the controller will try to achieve this value at the antenna by reducing the output power of the nRF52840's RADIO so that RADIO.TXPOWER + CONFIG_MPSL_FEM_NRF21540_TX_GAIN_DB equals 0 dBm.

Best regards,

Vidar