An example computing system includes a baseboard management controller (BMC), a motherboard, and a daughterboard communicatively coupled to the motherboard. The BMC includes a serial interface. The daughterboard includes a universal asynchronous receiver/transmitter (UART) terminal, a bridging chip, and a microcontroller communicatively coupled to the BMC via the bridging chip. The BMC establishes a serial connection, through the serial interface and the UART terminal, with the microcontroller.