# MW

For general information about this project see:
https://raw.githubusercontent.com/rpicopter/mw-config/master/README

This is a MultiWii service for *nix systems.
It consists of two modules - MultiWii service (mw) and a test client - command line interface (mwtest). It is designed to run on SoC such as Raspberry Pi, BeagleBone, Odroid, etc. but will also run on variety of other systems.

=== BACKGROUND ===
MultiWii itself (http://www.multiwii.com) is a general purpose software to control multirotor RC model. It is design to work on Arduino and similar boards. Its footprint is very small and therefore it is very attractive controller for advanced pilots. However it requires additional software and components to configure and to run (transmitter, receiver, Arduino IDE, Windows PC, etc). This makes it unnecessarily difficult for people without flight controller experience to use it.

This program (mw) is designed to change exactly this - to make MultiWii an attractive option to all the other flight controllers out there. It interfaces your MW controller with a computer. It works on *nix systems and is designed to extend the functionality of MultiWii. This way it becomes possible to for example implement WIFI based controller, Camera based position hold, and much more. It can also allow you to re-configure your controller in the field with the use of a mobile phone.

=== FUNCTIONALITY ===
MW is a service that exposes itself on a *nix systems for other programs to send and receive MultiWii commands. The abstraction layer is SHM IPC.
MW also provides an API for other programs to use for communication.

=== INSTALLATION ===
Ensure you have:
- libtool
- automake

Run libtoolize
Run ./autogen.sh (you will need automake for this to run)
Run make & make install

=== SERVICE USAGE (mw) ===
The service is a system wide application that connects to MultiWii controller over UART:
- a host service that runs on start-up of the system
- does 2 way translation between UART and clients using IPC (shm)
- handles UART communication with MW

Example:
$ ./mw -h
Usage:
-h	help
-b	run in background [defaults: 0]
-v	verbosity flag [defaults: 255]
-u	uart device path [defaults: /dev/ttyUSB0]
kiwi@lubuntu-mac:~/rpicopter/MW$ ./mw
(I) SHM: Initializing block: 0x7f1b52753000
(I) SHM: Initializing block: 0x7f1b52750000
(I) SHMMSP: Server initialized.
(I) UART: Openining /dev/ttyUSB0
(I) MW: Starting loop...
(I) SHMMSP: Found outgoing record id: 0
(I) SHM: Getting block id: 100 of block: 0x7f1b52753000, size: 34
(I) MSP: To UART message id: 100, data size: 0
(I) UART: tx: "24 4d 3c 00 64 64 ", len: 6
(I) SHMMSP: Found outgoing record id: 100
(I) SHM: Getting block id: 101 of block: 0x7f1b52753000, size: 34
(I) MSP: To UART message id: 101, data size: 0
(I) UART: tx: "24 4d 3c 00 65 65 ", len: 6
(I) UART: rx: "24 4d 3e 07 64 f0 03 00 00 00 00 70 e0 24 4d 3e 0b 65 f4 0a 3c 00 01 00 00 00 00 00 00 ad ", len: 30
(I) MSP: Queuing UART data, len: 30
(I) SHM: Setting 34 bytes of block id: 100 of block: 0x7f1b52750000
(I) SHM: Setting 34 bytes of block id: 101 of block: 0x7f1b52750000

=== TEST CLIENT USAGE (mwtest) ===
The application provided is a very basic command line client. It sends a couple of test messages (MSP_IDENT and MSP_STATUS) and waits for a response.
 
Example:
kiwi@lubuntu-mac:~/rpicopter/MW$ ./mwtest
(I) SHMMSP: Client initialized.
(I) MSP: Preparing message MSP_IDENT
(I) SHM: Setting 34 bytes of block id: 100 of block: 0x7f6f13700000
(I) MSP: Preparing message MSP_STATUS
(I) SHM: Setting 34 bytes of block id: 101 of block: 0x7f6f13700000
(I) SHMMSP: Found incoming record id: 101
(I) SHM: Getting block id: 100 of block: 0x7f6f136fd000, size: 34
(I) MSP: Parsing MSP_IDENT
(I) MSP: version: f0, multitype: 03, msp_version: 00, capability 70000000
(I) SHMMSP: Found incoming record id: 100
(I) SHM: Getting block id: 101 of block: 0x7f6f136fd000, size: 34
(I) MSP: Parsing MSP_STATUS
(I) MSP: cycleTime: 0af4, i2c_errors_count: 003c, sensor: 0001, flag: 00000000, currentSet: 00

=== API ===
API is defined as set of parsers and serializers (msp.h) and routines for accessing MW SHM (shm.h)

Example usage:

 struct S_MSG msg; //serialized message
 
 shm_client_init(); //initiate shm
 
 mspmsg_IDENT_serialize(&msg,NULL); //serialize MSP_IDENT message into msg
 
 shm_put_outgoing(&msg); //place it into the outgoing SHM block (service will pick it up and dispatch to MW)
 
 while (!shm_scan_incoming(&msg)) sleep(1); //wait for a response
 
 //message received in msg and can be parsed if needed using mspmsg_IDENT_parse(...)
 
 shm_client_end(); //close shm