# Configure the firmware
If required, firmware parameters (e.g. MQTT parameters) can be customized before building a new image. You can configure the firmware both from inside Embedded Studio IDE or from command line.
Most common settings you will want to configure are the following:
Asset Tracker > GPS > GPS Device
MQTT Broker url
Asset Tracker > IoTeX Hosted MQTT broker hostname
Network mode (NB-IoT/LTE-M)
Zephyr Kernel > Modules > Nordic nRF Connect > Libraries > nRF91 LTE Link control library > Select network mode
# Configure the firmware in Embedded Studio
From the Embedded Studio, before starting the build process, choose Configure nRF Connect SDK Project in the Project menu, and choose menuconfig in the pop-up window.
You can use the search box to quickly locate te parameters you want to customize, e.g. and search "mqtt" to customize MQTT specific parameters:
# Configure the firmware from command line
From command line, you can just run the following command to start the configuration menu:
this will start the configuration program from command line, allowing you to interactively set all the build configuration values for the firmware.