Enabling BeagleBone black UART with debian kernel 4.x
New kernel of debian has changed a lot of rules. which gave me pretty good pain when playing with my old programs. Fist is that: my favorite PyBBIO library does not work any more, since kernel 4.x use new universial IO access system, so these libraries has to figure out a way to support it, or use old 3.8kernel. The other think is that: usage of uart on board, you fist need to enable the function, Also need to takecare the pin muxing: https://stackoverflow.com/questions/35881761/enabling-uart-on-beaglebone-black You can change /boot/uEnv.txt First of all enable UARTS: cape_disable=bone_capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN cape_enable=bone_capemgr.enable_partno=BB-UART1,BB-UART2,BB-UART4.BB-UART5 Then don't forget to configure pinmux with appropriate dtbo's: ###Overide capes with eeprom uboot_overlay_addr0=/lib/firmware/BB-UART1-00A0.dtbo uboot_overlay_addr1=/lib/firmware/BB-UART2-00A0.dtbo uboot_overlay_addr2=/lib/firmware/BB-UART4-00A0.dtbo ub