Hi~ guys, i have been playing around this HLK-RM04 modules for weeks, this is the official product page: http://www.hlktech.net/product_detail.php?ProId=39 It seems to be a very handy device to do projects about internet of things, The price is very cheap($15), and it can run openwrt, i have built them successfully following the github's information here: https://github.com/JiapengLi/OpenWrt-HiLink-HLK-RM04 At first the instructions is incorrect about the trunk version, so you have to modify a patch, i have pull an issue and the author correct the instructions now, just follow the instructions, you'll be fine, the building take about a half hour, during building keep internet access, a lots of package have to be downloaded. Tell me if you have any questions.
Back to arduino side, the original firmware with two uarts support is really handy, you can use one uart to listen to local network as a server, while use the other as a client to send requests to internet website at the same time.
i'm thinking about creating an arduino library for this module, two plans are listed: 1.Try to follow Arduino Yun's design, and migrate the Linino(the linux running on Yun's Atheros SoC) to HLK-RM04 module. Pros: It will be nice to use Bridge library to communicate with the HLK-RM04 module just like the Yun's board, the arduino code can be directly used without any modify. Cons: Linino project seems not mature, i can not even find the source code(if you know it, tell me please! looking for building them on HLK-RM04) .
2.Create a library based on the HiLink-HLK-RM04 original firmware, That is about creating a middle layer to simplify the AT commends and the http requests and so on. Pros: It seems easier to just make a api layer to translate some code to uart, and the original firmware prove to be extremely stable.(especially the auto reconnect after disconnect function in TCP layer). Cons: You have to use a new library and it will be greatly different from the Bridge library. And due to the closed source firmware, you cant build a module youself(in fact i dont think the module can be build by individuals even with the source, the PCB are just too complicated).
So what's you guys opinion about what the library should be?