Beaglebone Black comes with analog input pins and analog-to-digital converter (ADC) modules. The process I followed to access these pins is documented here.
Beaglebone Black, PC running on Linux system (Ubuntu ver 20.04)
Serial to USB cable, USB type A to mini B cable
The GPIO port is one of the main ways to establish connection between the board and external circuit. The process I followed to setup such connnection with a Linux kernel module is documented here.
Beaglebone Black, PC running on Linux system (Ubuntu ver 20.04)
Serial to USB cable, USB type A to mini B cable
Jump wires, LED, transistor (BC547), resistors
Having a cross compilation environment on the host PC can bring great convenience to the development of kernel modules. In the process, there are a lot of things that require attention. The process I followed is documented here for future reference.
The building of out-of-tree modules depends on many files (configs, kernel Makefile, headers, /scripts directory etc.) from the kernel. They can be obtained by downloading and building a kernel or installing the headers directly. The first approach is introduced here. Note that a full kernel build is not necessary, since the kernel image itself is not required.
To make the setup capable of cross compilation, the kernel source code, configuration and compiler need to match those of the target device.
The kernel image that came with the board is usually outdated. Thus, I decided to update it to the latest image by flashing the onboard eMMc with an SD card. The process I followed is documented here.
Beaglebone Black, PC running on Ubuntu (ver 20.04)
Serial to USB cable, USB type A to mini B cable, power adapter
Micro SD card and adapter
U-boot is an open-source boot loader used in embedded devices such as the Beaglebone Black. Like many other boot loaders, it can be configured to have different behaviors. However, saving the configuration may not be as straightforward as it seems. In this article, the issues I encountered and the corresponding solutions are documented, hopefully they can be helpful for others.
The u-boot that came with the board is compiled to save its configurations to the SD card, regardless of the availability. Thus, running saveenv without one will generate a "Card did not respond to voltage selected" error. This problem can be solved by adding an SD card or flashing the firmware. The second solution can be found on Bootlin's github: https://github.com/bootlin/training-materials/tree/master/lab-data/common/bootloader/beaglebone-black
Sharing data between host computer and the board is crucial in embedded system development. The process I followed to set up TFTP and NFS connection on Beaglebone Black is documented here, hopefully it can be helpful to others.
Beaglebone Black, PC running on Ubuntu system (ver 20.04 in my case)
serial to USB cable, USB type A to mini B cable