jdh-8 | An 8-bit minicomputer with a fully custom architecture

 by   jdah C Version: Current License: MIT

kandi X-RAY | jdh-8 Summary

kandi X-RAY | jdh-8 Summary

jdh-8 is a C library typically used in Embedded System applications. jdh-8 has no bugs, it has no vulnerabilities, it has a Permissive License and it has medium support. You can download it from GitHub.

An 8-bit minicomputer with a fully custom architecture

            kandi-support Support

              jdh-8 has a medium active ecosystem.
              It has 1151 star(s) with 85 fork(s). There are 19 watchers for this library.
              It had no major release in the last 6 months.
              There are 7 open issues and 23 have been closed. On average issues are closed in 14 days. There are 2 open pull requests and 0 closed requests.
              It has a neutral sentiment in the developer community.
              The latest version of jdh-8 is current.

            kandi-Quality Quality

              jdh-8 has 0 bugs and 0 code smells.

            kandi-Security Security

              jdh-8 has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.
              jdh-8 code analysis shows 0 unresolved vulnerabilities.
              There are 0 security hotspots that need review.

            kandi-License License

              jdh-8 is licensed under the MIT License. This license is Permissive.
              Permissive licenses have the least restrictions, and you can use them in most projects.

            kandi-Reuse Reuse

              jdh-8 releases are not available. You will need to build from source code and install.
              Installation instructions are not available. Examples and code snippets are available.

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            jdh-8 Key Features

            No Key Features are available at this moment for jdh-8.

            jdh-8 Examples and Code Snippets

            No Code Snippets are available at this moment for jdh-8.

            Community Discussions


            Is relying on integer promotion a bad programming practice?
            Asked 2022-Mar-31 at 19:52

            I'm currently writing some code for embedded systems (both in c and c++) and in trying to minimize memory use I've noticed that I used a lot of code that relies on integer promotions. For example (to my knowledge this code is identical in c and c++):



            Answered 2022-Mar-31 at 19:52

            Your question raises an important issue in C programming and in programming in general: does the program behave as expected in all cases?

            The expression (brightness * maxval) / 100 computes an intermediary value brightness * maxval that may exceed the range of the type used to compute it. In Python and some other languages, this is not an issue because integers do not have a restricted range, but in C, C++, java, javascript and many other languages, integer types have a fixed number of bits so the multiplication can exceed this range.

            It is the programmer's responsibility to ascertain that the range of the operands ensures that the multiplication does not overflow. This requires a good understanding of the integer promotion and conversion rules, which vary from one language to another and are somewhat tricky in C, especially with operands mixing signed and unsigned types.

            In your particular case, both brightness and maxval have a type smaller than int so they are promoted to int with the same value and the multiplication produces an int value. If brightness is a percentage in the range 0 to 100, the result is in the range 0 to 25500, which the C Standard guarantees to be in the range of type int, and dividing this number by 100 produces a value in the range 0 to 100, in the range of int, and also in the range of the destination type uint8_t, so the operation is fully defined.

            Whether this process should be documented in a comment or verified with debugging assertions is a matter of local coding rules. Changing the order of the operands to maxval * brightness / 100 and possibly using more explicit values and variable names might help the reader:

            Source https://stackoverflow.com/questions/71340614


            Python coding standard for Safety Critical Applications
            Asked 2022-Mar-20 at 15:46

            Coming from C/C++ background, I am aware of coding standards that apply for Safety Critical applications (like the classic trio Medical-Automotive-Aerospace) in the context of embedded systems , such as MISRA, SEI CERT, Barr etc.

            Skipping the question if it should or if it is applicable as a language, I want to create Python applications for embedded systems that -even vaguely- follow some safety standard, but couldn't find any by searching, except from generic Python coding standards (like PEP8)

            Is there a Python coding guideline that specificallly apply to safety-critical systems ?



            Answered 2022-Feb-02 at 08:46

            Top layer safety standards for "functional safety" like IEC 61508 (industrial), ISO 26262 (automotive) or DO-178 (aerospace) etc come with a software part (for example IEC 61508-3), where they list a number of suitable programming languages. These are exclusively old languages proven in use for a long time, where all flaws and poorly-defined behavior is regarded as well-known and execution can be regarded as predictable.

            In practice, for the highest safety levels it means that you are pretty much restricted to C with safe subset (MISRA C) or Ada with safe subset (SPARK). A bunch of other old languages like Modula-2, Pascal and Fortran are also mentioned, but the tool support for these in the context of modern safety MCUs is non-existent. As is support for Python for such MCUs.

            Languages like Python and C++ are not even mentioned for the lowest safety levels, so between the lines they are dismissed as entirely unsuitable. Even less so than pure assembler, which is actually mentioned as something that may used for the lower safety levels.

            Source https://stackoverflow.com/questions/69673807


            Forward declaration issue, two compilers
            Asked 2022-Mar-18 at 22:00

            I've been developing in C using eclipse as my IDE in my virtual machine with ubuntu, I've made some progress and I wanted to test them in the real product which is an embedded system using powerpc.

            In order to compile that program for our product I use Code::Blocks in Windows but the compiler is a powerpc version of the gcc.

            The same code is giving me an error in the powerpc version that doesn't appear in the ubuntu version.

            I have two header files gral.h and module_hand.h as follows:

            The gral.h file:



            Answered 2022-Mar-17 at 18:30

            In the gral.h header file, you define profile_t using typedef, then you redefine profile_t with another typedef in module_hand.h. You should just define the struct PROFILE in gral_h and include gral.h in module_hand.h.


            Source https://stackoverflow.com/questions/71516556


            How can I save local changes that have been done in Yocto repository?
            Asked 2022-Mar-11 at 08:27

            I'm working on some Linux embedded system at the moment and using Yocto to build Linux distribution for a board.

            I've followed Yocto build flow:

            • download layers sources
            • build image
            • flash image into the board or generate SDK.

            Everything works great. However I was required to add some changes to local.conf, probably add some *.bbapend files, systemd services and so forth. So, I'm wondering how can save that local changes in case if I'll want to setup a new build machine or current one will be corrupted.

            Should I create a custom image or layer that will inherit everything from a board manufacturer one and add changes and functionalities that are needed to me? Or something else?



            Answered 2022-Mar-11 at 08:27

            Generally when working on a custom project with Yocto, here is what possibly you will need:

            First of all, you need to create your custom layer

            Source https://stackoverflow.com/questions/71427504


            Building a static array at compile time
            Asked 2022-Mar-08 at 22:33

            I have a few large static arrays that are used in a resource constrained embedded system (small microcontroller, bare metal). These are occasionally added to over the course of the project, but all follow that same mathematical formula for population. I could just make a Python script to generate a new header with the needed arrays before compilation, but it would be nicer to have it happen in the pre-processor like you might do with template meta-programming in C++. Is there any relatively easy way to do this in C? I've seen ways to get control structures like while loops using just the pre-processor, but that seems a bit unnatural to me.

            Here is an example of once such map, an approximation to arctan, in Python, where the parameter a is used to determine the length and values of the array, and is currently run at a variety of values from about 100 to about 2^14:



            Answered 2022-Mar-08 at 22:33

            Is there any relatively easy way to do this in C?


            Stick to a Python script and incorporate it inside your build system. It is normal to generate C code using other scripts. This will be strongly relatively easier than a million lines of C code.

            Take a look at M4 or Jinja2 (or PHP) - these macro processors allow sharing code with C source in the same file.

            Source https://stackoverflow.com/questions/71396438


            dpkg-buildpackage reapplies patches to debian/rules
            Asked 2022-Mar-07 at 18:33

            I'm trying to build libc6 with a custom prefix by modifying the prefix=/usr line in debian/rules. However, this fails because the patch is applied multiple times. Curiously, patching another file does not result in the same error. I've distilled the failure down to this script:



            Answered 2022-Mar-07 at 18:33

            The debian/rules directory is special [citation needed] and shouldn't be patched using the usual quilt commands. You can modify them directly before building the package or use the patch command (patch -p1 in this case).

            Source https://stackoverflow.com/questions/71331029


            How to create a frequency table of each subject from a given timetable using pandas?
            Asked 2022-Mar-05 at 16:06

            This is a time table, columns=hour, rows=weekday, data=subject [weekday x hour]



            Answered 2022-Mar-05 at 16:06

            Use melt to flatten your dataframe then pivot_table to reshape your dataframe:

            Source https://stackoverflow.com/questions/71363338


            Python module 'datetime' has no attribute 'datetime_CAPI'
            Asked 2022-Jan-30 at 13:03

            I need to run numpy in an embedded system that has an ARM SoC, so I cross-compiled Python 3.8.10 and Numpy using arm-linux-gnueabihf-gcc. Then I copied both executables and libraries to the embedded system. But when I try to import numpy I get the following error:



            Answered 2022-Jan-30 at 13:03

            I found the problem, it was a Python compilation issue. I used the following commands to compile Python and the problem was solved.

            Source https://stackoverflow.com/questions/70910450


            Initialising an array while extracting __VA_ARGS__ from a macro function
            Asked 2022-Jan-28 at 00:00

            I am trying to write a special type handling for array data redundancy. The idea is to define and declare an array globally at compile time with fixed size, but the size is different to each declared array. This is the idea:



            Answered 2022-Jan-28 at 00:00

            I feel like a solution to this would be one of those macros that consists of two dozen sub-macros, and those solutions always make me decide to solve the problem some other way. Macros can do some things, but they're not a full programming language and so they're limited in what they can do.

            I would just write a small utility to convert the raw data to C code and then #include that. You can compile the utility as part of your compilation process and then use it to compile the rest of your code. So your data.txt could just say "test 1 2 3 4 5 6 7" and your utility would output whatever declarations you need.

            Source https://stackoverflow.com/questions/70864893


            Python: pixel manipulation pefrormance. Virtual desktop for embedded device
            Asked 2022-Jan-22 at 14:05

            I am looking for an efficient way of pixel manipulation in python. The goal is to make a python script that acts as virtual desktop for embedded system. I already have one version that works, but it takes more than a second to display single frame (too long).

            Refreshing display 5 times per second would be great.

            How it works:

            1. There is an electronic device with microcontroller and display (128x64px, black and white pixels).
            2. There is a PC connected to it via RS-485.
            3. There is a data buffer in microcontroller, that represents every single pixel. Lets call it diplay_buffer.
            4. Python script on PC downloads diplay_buffer from microcontroller.
            5. Python script creates image according to data from diplay_buffer. (THIS I NEED TO OPTIMIZE)

            diplay_buffer is an array of 1024 bytes. Microcontroller prepares it and then displays its content on the real display. I need to display a virtual copy of real display on PC screen using python script.

            How it is displayed:

            Single bit in diplay_buffer represents single pixel. display has 128x64 pixels. Each byte from diplay_buffer represents 8 pixels in vertical. First 128 bytes represent first row of pixels (there is 64px / 8 pixels in byte = 8 rows).

            I use python TK and function img.put() to insert pixels. I insert black pixel if bit is 1 and white if bit is 0. It is very ineffective. Meybe there is diffrent class than PhotoImage, with better pixel capability?

            I attach minimum code with sample diplay_buffer. When you run the script, you will see the frame and execution time.

            Meybe there would be somebody so helpful to try optimize it? Could you tell me faster way of displaying pixels, please?


            Sample frame downloaded from uC

            And the code (you can easily run it)



            Answered 2022-Jan-22 at 14:05

            I don't really use Tkinter, but I have read that using put() to write individual pixels into an image is very slow. So, I adapted your code to put the pixels into a Numpy array instead, then use PIL to convert that to a PhotoImage.

            The conversion of your byte buffer into a PhotoImage takes around 1ms on my Mac. It could probably go 10-100x faster if you wrapped the three for loops into a Numba-jitted function but it doesn't seem worth it as it is probably fast enough.

            Source https://stackoverflow.com/questions/70738848

            Community Discussions, Code Snippets contain sources that include Stack Exchange Network


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            You can download it from GitHub.


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