Hello everyone! Christmas arrived a bit earlier for NuttX as I would like to donate some of my personal code to the community!
A bit of context. Over the years that I am working on embedded systems, I have developed lots of software that I use in my projects. Some of it is quite general-purpose, or useful for other applications, and I have found my self reusing it quite often. In fact, there are some things that I use in practically all firmwares that I have developed over the last years. I always wanted to open-source this software so other people can benefit from it. But I never managed to do so. Open-sourcing needs some effort, the software needs maintenance, documentation and support, and most importantly in most cases a "porting layer" needs to be developed. Last but not least, every project needs a bit of "marketing" and "advertising" so others can learn about your work and use it. For the last couple of years I have been using NuttX a lot, and I have ported most of the aforementioned software to NuttX. I believe that NuttX and its community are perfect for me to publish my code, instead of creating a ton of small repos, of questionable usefulness and increasing my workload considerably. It is very important that I can get immediate feedback from the community, learn what people are actually interested in (instead of investing on software that no one needs), and provide actual and *working* samples of the code (as NuttX already supports a ton of different boards and arches). Using POSIX as the porting layer is also awesome. That being said, my free time is still exceptionally limited and I cannot do this myself. I still need the help of the community, and most importantly I need to see interest in a piece of software before putting any work on it. So, what I offer: * I offer various codes, fully featured, production ready and tested. * All code will be offered for free (of course) and under Apache licensing. * I will provide support to those working on these codes, to my best ability. * I will contribute to testing everything integrated to NuttX, as hardware availability allows me. * I will do some licensing check, to ensure code is 100% original and mine, or state the licenses of the projects I borrowed code from. What I ask for: I need people that are interested in each of these codes to integrate them into NuttX apps. You just have to pick what it is interesting to you, contact me to provide you with the code, and integrate it to NuttX. You will need to: * Add the code into the NuttX apps repo, and ensure Kconfig and the build system use the code properly (should be trivial). * Adapt the file format and the coding style to the NuttX one (this may need some work, but it can also be automated). * Provide an example app, something that someone can run to use or demo the new code. * Test and verify the example app on actual hardware (I may be able to cross-check it on my hardware too). The code that I offer (for the moment): *** Lua v5.2.4 *** I know that there is already a Lua app for NuttX. But for anyone using it, it may be beneficial to use my work. First and foremost, I have ported the eLua LTR patch to Lua 5.2. This patch dramatically reduces the memory usage of Lua. In fact, I found out that it is crucial to have this patch enabled for any actual real-life usage of Lua on any "normal" MCU. I have created a Kconfig for all Lua configurations, so it can integrate with NuttX better. I have also made some other minor changes to the code that might be interesting for you. For example there is a simplistic sandboxing option. *** MQTT Broker *** Yes, a full-blown, spec-compliant MQTT Broker! To my knowledge there is no other open-source and portable MQTT broker for embedded systems. It follows the MQTT v3.1.1 specification as closely as possible. I think there is only one violation, needed due to its embedded nature, but in all practical cases you may consider it fully compliant. It has been tested with dozens of devices, and it performs greatly. There are a couple of things that may need to be improved, but are trivial, and will not affect the normal use of the software. I know that such a broker may not be your best option for a proper and large installation of IoT devices, but it is exceptionally useful for at least the following cases: * You have only a few devices, isolated (no internet), that you need to connect, and you want to avoid the cost (and maintenance) of a proper broker (e.g. Raspberry Pi). * You need to directly communicate with a device that only supports MQTT. Instead of going through an external server, you run the server locally, and communicate with the device directly. *** MQTT Client *** A production-tested, robust and quite flexible MQTT client. I know that there are plenty of such clients available out there, but here is another one. Back in the day I tried to use the Eclipse Paho library. I found it to be a horrible piece of software. Crashes, buffer overflows, spec violations, missing functionality and more. I don't know whether it has improved now, but back then I rolled-out my own implementation. There were not many other alternatives available, and Paho did not worth contributing to it. It needed so much work, that starting from scratch was much easier. Then, when I started using NuttX, I saw support for MQTT-C. Well, I tried it and I wasn't greatly satisfied (I don't remember the reasons). So I decided to keep using my own (and well tested) implementation. So NuttX, instead of relying on an external project, now can have its own client. *** Settings Storage *** This is probably my favorite. A key-value pairs storage for non-volatile settings or configurations. Very needed when you need to adjust the system's operation in run-time, download parameters etc. It acts in two layers: the settings API and the actual storages used. The settings can store or retrieve key-value pairs. Type casts are supported and are performed automatically. For example you can store the string "true" and then read it as the int 1 etc. There is support for caching writes (minimizing overhead and reducing wear on the actual storage medium). There are signal notifications when a setting value is changed. The bottom layer, the storages, is responsible for actually reading and writing the settings map to the physical mediums. Every storage can also format the data according to its type. For the moment there are only ASCII and binary storages, but it would be very easy to expand this to JSON, XML, YAML and more. There is support for multiple storages used simultaneously, and synchronization between them (for example I usually use both the MCU's Flash and the SD card). *** FTP Client *** This is a client that I had developed before I learned about NuttX. I also tried NuttX FTPc, but I experienced may failures that I never got the time to troubleshoot. I just went back to the tried solution. One thing that I didn't really like in NuttX ftpc, it was that it is very taciturn. When something went wrong, you couldn't understand what the issue is. The error information of this library is a bit better. If an alternative ftpc implementation is of interest to anyone, the code is available. *** JSON Parser *** This is a very minimal parse-only JSON implementation. The motivation behind developing this was memory consumption. This parser can open an arbitrarily large JSON file (even MBs), using only a few bytes of RAM! (If I recall correctly only 20 bytes!) Although there are other options there for you, if you need the smallest possible memory footprint, this is your parser. *** XML Parser *** Exactly as above with JSON. A minimal parser, that can open any file using just a few bytes of RAM. If you need something simple or you have memory constraints, use this. *** XTEA *** Simple XTEA encryption and decryption. Very useful when you need a quite fast way to encrypt (or obscure) some data. (Need to check licensing!) *** Sun Calculations *** A small library that can do astronomical calculations for the sun. That is sunrise time, sunset, day duration and more. *** Geolocation *** I used the ipgeolocation.io API and NuttX wget to get geolocation information about the device. Nothing special, but it may serve as a working example, or even inspiration for others... If everyone is interested in any of the above please contact me. *PLEASE be responsible, and respectful.* (I am sure you will! :D ) If you request for a piece of software* you will have to help to get this into NuttX, and not only use it for your own personal gain*.
