@victoriano Serial ports of Omega2S+ on Omega2 DASH Unfortunately I don't have such device so according to the schematic: UART0 (/dev/ttyS0) - Serial Console (via an on-board CP2104 USB-to-Serial chip - Micro USB port) TXD0 GPIO12 - CP2104 RXD0 RXD0 GPIO13 - CP2104 TXD0 UART1 (/dev/ttyS1) TXD1 GPIO45 - Expansion Header GPIO45 RXD1 GPIO46 - Expansion Header GPIO46 UART2 (/dev/ttyS2) TXD2 GPIO20 - not exposed RXD2 GPIO21 - drives LEDA via the Q3 PNP inverter You could connect a USB-to-Serial converter/cable to the USB Host Port to get one more serial line.