embedded

问题 I'm working on a variscite board with a yocto distribution and python 2.7.3. I get sometimes a Bus error message from the python interpreter. My program runs normally at least some hours or days before the error ocours. But when I get it once, I get it directly when I try to restart my program. I have to reboot before the system works again. My program uses only a serial port, a bit usb communication and some tcp sockets. I can switch to another hardware and get the same problems. I also used

问题 The old versions show am335x_boneblack_defconfig(branch v2017.01 instead of the master) file inside the directory but I am not able to see it in the newer version.So which branch should I use to build U-Boot for BeagleBone Black? Under boards/ti/am335x/, I saw that am335x_* can be used for BeagleBone Black. Any help will be appreciated? 回答1: I think you can use configs/am335x_evm_defconfig - see line 36: CONFIG_OF_LIST="am335x-evm am335x-bone am335x-boneblack am335x-evmsk am335x-bonegreen

问题 I know that this question is general, but I couldn't find a tutorial or a good coding way to convert Arduino code (I mean the code that we are writing on Arduino software and it doesn't matter for Arduino Uno or Mega or ... ) even if a small sample. Is there a tutorial? I just want to learn the technique, and I know that it depends on the project. 回答1: Arduino code is , more or less, C code. The unique things that happen with Arduino is that the code is preprocessed (for example, they give

问题 I am trying to install rtems 5 on my ubuntu-19.04 machine, using the instructions in QuickStart, everything is ok until section 2.7, when it appears that the gdb that was built is missing the "sim" target. The complete sequence of commands is : 2022 mkdir -p $HOME/quick-start/src 2023 cd $HOME/quick-start/src 2024 git clone git://git.rtems.org/rtems-source-builder.git rsb 2025 git clone git://git.rtems.org/rtems.git 2026 cd $HOME/quick-start/src/rsb/rtems 2027 ../source-builder/sb-set-builder

问题 Dear stack overflow users, I have built a device with a master device, and a network of 10 slaves. All of them communicate via 4 wire SPI. Right now I am writing the program for both boards, and they don't seem to be working, I do not get expected responses. I have a master board, and 10 of identical slave boards. The protocol is simple - as with SPI any transaction is initiated by the master device, and a command is sent. The selected slave then receives aforemetioned command, sets a busy

问题 Dear stack overflow users, I have built a device with a master device, and a network of 10 slaves. All of them communicate via 4 wire SPI. Right now I am writing the program for both boards, and they don't seem to be working, I do not get expected responses. I have a master board, and 10 of identical slave boards. The protocol is simple - as with SPI any transaction is initiated by the master device, and a command is sent. The selected slave then receives aforemetioned command, sets a busy

问题 Is it okay to cast function location with void pointer though function pointers size is not always the same as opaque pointer size? I already did search about opaque pointers , and casting function pointers . I found out function pointers and normal pointers are not the same on some systems. void (*fptr)(void) = (void *) 0x00000009; // is that legal??? I feel I should do this void (*fptr)(void)= void(*)(void) 0x00000009; It did work fine , though I expected some errors or at least warnings I

问题 Is it okay to cast function location with void pointer though function pointers size is not always the same as opaque pointer size? I already did search about opaque pointers , and casting function pointers . I found out function pointers and normal pointers are not the same on some systems. void (*fptr)(void) = (void *) 0x00000009; // is that legal??? I feel I should do this void (*fptr)(void)= void(*)(void) 0x00000009; It did work fine , though I expected some errors or at least warnings I

问题 So, what I have learned so far is that CPU programs the source address, dest address, word count and the direction to the DMA controller whenever it needs to transfer the data from say a harddrive. But in this example, the hard drive is just a dumb device, so it makes sense because harddrive can never initiate a data transfer. But, what if we have connected the serial port where in certain instances we are going to get 8 bits of data. I know the DMA controller is used for large memory

问题 I am creating an event whenever my Raspberry Pi's GPIO pin has a falling edge. However, I want to disable this event for a certain amount of time (5 seconds for example) after each time it runs. I want the event to be enabled again after that time period. My first thought was just to use sleep(5) within the actual event function. But I believe this will not work due to the event being ran in a separate thread. Can anyone point me in the right direction to what I am trying to accomplish? This