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I'm having difficulties with my BBB on CAN communication like for months... I'd be really pleased if you could give me just a little help!

I'm working on CAN protocol between BBB and another CAN device. The another device is confirmed to be working alright with CAN. I'm using my BBB with Cloud9 platform on windows laptop, and on the another device, it's using CAN0.

I have set the 'config-pin' on BBB like below using CAN1, and I tried 'cansend' utility. The bitratre value on the another device is also set to be equal.

I'm trying to setup a Raspberry Pi 3 B+ with a Waveshare BME280 Environmental Sensor. I followed this guide to wire the cables and ran the supplied bme280.py script. My sensor has 2 additional cables, the CS and ADDR/MISO, that are not present in the model on the guide but the rest are plugged in to the same GPIO pins. The I2C and SPI interfaces are enabled and I am running the latest Raspbian OS Lite.

When I run the script, I get the following message:
Traceback (most recent call last):
File "bme280.py", line 172, in
main()
File "bme280.py", line 161, in main
(chip_id, chip_version) = readBME280ID()
File "bme280.py", line 56, in readBME280ID
(chip_id, chip_version) = bus.read_i2c_block_data(addr, REG_ID, 2)
OSError: [Errno 121] Remote I/O error

There's another odd issue: when I run i2cdetect -y 1 I get every line with dashes, but if I run it a second time immediately after, I get x77 to show up, but x76 still doesn't.

I found a similar thread and tried modifying my /boot/config.txt file by adding i2c_baudrate=100000 and rebooting but that did not fix it.

I made sure to test the pi using gpiotest and the results came back as
Skipped non-user gpios: 0 1 28 29 30 31
Tested user gpios: 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Failed user gpios: None

I had gotten similar issues using a DHT11 sensor and running Adafruit libraries and got an error signifying there was no data flowing from the sensor. I tried using several different sensors and Raspberry Pis and have reinstalled the OS several times over. At this point, I'm not sure how to proceed. Any help is appreciated.

I am trying to use CAN J1939 standard on an embedded Linux system running Ubuntu 18.04, kernel 5.4.0-52-generic.

This elinux page indicates that j1939.h "got in the mainline kernel since v5.4". And kernel.org's documentation for j1939 implies that it is in the main kernel.

Lastly, I do have can-utils installed.

When I compile a cpp file with #include , I get a no such file or directory error.

I've gone through linux/can directory to confirm and j1939.h is not there. Is there any reason why my v5.4 kernel wouldn't have j1939.h? How can I best use j1939.h in my program?

I was trying my hands on addr2line to convert a "pc" register value from a kernel oops (example) to a line in the kernel code. I believe that the value of the program counter represents a virtual address.

Now this post on Stack Overflow says that we generally provide an offset to addr2line and not a virtual address. VA can only be used when the address space randomization is turned off. Does this hold true for a kernel as well? I believe it should.

This Embedded Linux Conference talk on slide 14 also makes use of the program counter value to jump to the line in code, but I believe this would work only work when the address space randomization is off. Otherwise, once the virtual memory is initialized, it's possible that the kernel gets relocated randomly. In this case, any virtual address picked from an oops should not make any sense to addr2line. This is all theory. I have 2 questions now:

1. Is my understanding correct? If not, please correct me.
2. How do we turn off the address space randomization for a kernel so that the location of a symbol can be predicted?

I'm trying to use UART5 with python, I've edited uEnv.txt to disable HDMI

I've upgraded BeagleBone Black to Debian 10 BeagleBoard.org Debian Buster IoT Image 2020-04-06

uname -a shows:

Linux beaglebone 4.19.94-ti-r45 #1buster SMP PREEMPT Thu Jun 18 19:18:41 UTC 2020 armv7l GNU/Linux

I'm trying to use UART5 with python, but it fails with every UART, python shows the message:

py_setup_uart(UART5): set_pin_mode() failed for pin=P8_38Traceback (most recent call last):

when I execute config-pin it shows:

/sys/devices/platform/ocp/ocp:P8_34_pinmux/state failed, No such device

also there is no slots: /sys/devices/bone_capemgr.*/slots': No such file or directory

dmesg | grep serial shows:

I have an SD card with a standard Beaglebone Debian image. I also have the MLO and u-boot.img files from building u-boot. I'd like to install the new u-boot on the SD card and then flash the modified image to MMC on a Beaglebone Black.

I can flash onboard MMC from the SD card just fine. I can also connect to the board over serial and stop in u-boot.

What I don't know how to do is write the new u-boot to the SD card correctly. I've tried a few things:

1. These elinux instructions are for erasing the SD card and creating a new bootable partition. I didn't actually try this because I want to install the new u-boot to an existing image.

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