Showing posts from October, 2017

AUTOSAR and CRC calculation

If you find yourself reading AUTOSAR document Specification of CRC Routines you are probably looking for a solution on how to implement it in your code. This is short instruction without explaining how CRC works. It includes working CRC code with examples from the mentioned documentation. Explanation of CRC8 CRC 8 it means, the polynomial of CRC is 8 bit long.  Explaining chapter 7.2.1: CRC result width - it is the return value, it says it is 8 bits long Polynomial - this value is used to calculate CRC. In this case, it is 0x1D Initial value - CRC calculation start with this value. It is usually all F's or zeros.  Input data reflection - it says if the data which you want to do CRC need to be reflected or not. Example of data reflection: hex: 0x73 or binary: 1110011, reflected value is: 1100111 or hex 0x67 Result data reflected - same as input data, but the only result is reflected XOR value - result value need to be XOR-ed with this value before is r

Running Nuttx RTOS on EK-TM4C123GXL

This is the short tutorial on how to build and flash Nuttx, the real-time operating system on TM4C123G LaunchPad on fresh installed Ubuntu 16.04 LTS. More about Nuttx for TM4C123G LaunchPad: Building Nuttx In terminal run this commands: mkdir nuttxdir cd nuttxdir git clone git clone git clone sudo apt-get install gperf flex bison libncurses5-dev cd tools/kconfig-frontends/ ./configure --enable-mconf make sudo make install sudo ldconfig cd ../.. Without libncurses5-dev you will have the problem with kconfig-mconf, so don't miss to install it.  cd nuttx/tools ./ tm4c123g-launchpad/nsh cd .. make menuconfig Inside menu config, you need select System Type -> Toolchain Selection -> Generic GNU EABI toolchai

Debugging EK-TM4C123GXL with Visual Studio Code on Linux

If you have TM4C123G LaunchPad Evaluation Kit and you like Visual Studio Code here is how to setup debugging on this board. This is the tutorial how to do that on clean Ubuntu 16.04 LTS. ARM GCC Compiler Setup Download the latest GCC cross compiler for the ARM from here: In the time of writing this text, the last one is    gcc-arm-none-eabi-5_4-2016q3-20160926-linux.tar.bz2 Run this commands in Linux console. wget tar -jxf gcc-arm-none-eabi-5_4-2016q3-20160926-linux.tar.bz2 rm gcc-arm-none-eabi-5_4-2016q3-20160926-linux.tar.bz2 exportline="export PATH=$HOME/gcc-arm-none-eabi-5_4-2016q3/bin:\$PATH" echo $exportline >> ~/.profile source ~/.profile sudo dpkg --add-architecture i386 sudo apt-get update sudo apt-get install libc6:i386 lib32ncurses5 Without i386 architecture you will