Maciej Witkowiak mwitkowiak@gmail.com, ytm@elysium.pl
This is a client for kRPC, a mod for Kerbal Space Program game.
It allows you to build Internet-of-Kerbals with tiny WiFi-enabled clients for remote monitoring and control of Kerbalkind aerospace vehicles.
This is a reimplementation of kRPC C++ client adapted to ESP8266 environment with low RAM usage.
Instead of reference Google Protobuf library I used Nanopb.
This version is based on kRPC-0.3.6 protocol.
An awesome game where you fail and fail again, and then you crash and burn.
A mod for KSP that allows to control what happens in the game from outside scripts written in popular languages like Python, Lua, C# and C++. "RPC" stands for "Remote Procedure Call" and the connection is provided by a TCP/IP server running on computer with the game. The scripts may run on remote machines and connect to the game over network.
Incredible platform for custom amateur Internet-of-Things development. This is a very low cost WiFi chip with full TCP/IP stack and microcontroller.
- remote monitoring of KSP flight parameters to show on custom physical displays (LEDs, LCDs, custom meters, etc.)
- remote control of KSP flight with custom physical controls (joysticks, buttons, knobs, etc.)
- interface between higher-level kRPC protocol over WiFi and simple serial communication with AVR Arduinos (KSP Serial IO on steroids)
- translator between Internet-of-Things (think MQTT protocol) and Kerbal-of-Things universe
- Arduino IDE 1.6.x
- ESP8266 core for Arduino
- Kerbal Space Program game with kRPC mod installed
This was developed and tested on Wemos D1 mini board. Basically this is ESP-12F module put on a board with integrated serial to USB interface.
You can find more information how to get started with Arduino on Wemos pages.
At the moment this is just a proof of concept - to show that it is possible to do at all. The example code is a direct reimplementation of kRPC tutorial script. This code sends a rocket to space, until it reaches 100000m apoapsis and brings back safely to Kerbin.
I implemented only those RPC calls that are actually used. There should be enough of flash space left to put majority of calls from all possible services defined by kRPC.
My C++ wrapper over Nanopb is clumsy, but at least it hides all the ugly callbacks for each of the possible variable types.
The object model for SpaceCenter service is a joke, it is just a thin wrapper over kRPC calls. It's your responsibility to keep track of vessel, control, flight, orbit references.
I learn as I code, so I would also welcome any suggestions how to improve the code also with C++11 features in mind.
Just follow instructions from Nanopb
Update the copy of krpc.proto file from kRPC repository
Compile .proto file to krpc.pb file with protoc compiler that comes with Google Protobuf
protoc -okrpc.pb krpc.proto
Then process it with nanopb generator:
nanopb/generator/nanopb_generator.py krpc.pb