The article covers the setup of the MultiWii control electronics for the S-QUAD quadcopter. The controller is based on the MultiWii, an open platform initially aimed at exploiting gaming console sensors. HobbyKing HK MultiWii 328P is an all-in-one board (standard 50x50mm PCB) specifically designed for RC models based on the ATMega328P MCU (same as many Arduino boards) and a set of essential sensors.
|FT232RL||FTDI||USB to RS232 converter|
|ITG3205||InveSense||Triple axis gyro|
|BMA180||BOSCH Sensortech||Triple axis accelerometer|
|BMP085||BOSCH Sensortech||Barometric pressure and temperature sensor|
See MultiWii 328P product page over at HobbyKing for further information and development material.
Credits to pighixx for the ATMega pinout.
HobbyKing flight controller is shipped ready-to-fly with MultiWii 2.20 firmware for a quad-rotor in X configuration (the same I intend to fly). To update the firmware to the latest release (2.40 at the time of writing) or to tweak the default configuration (editing the file config.h) follow the documentation on the wiki.
Alternative RC approaches are proposed to replace the standard multichannel receiver: Bluetooth module (BTBee from Iteadstudio) and WiFi module (ESP8266). These units can be coupled to the MultiWii and used to operate a drone. The range provided by such solutions is limited making them not suitable for long-range outdoor flights. Yet they are cheap solution to familiarise with the flight controller.
The first attempt to setup a Bluetooth connection with an Arduino board (same hardware of the HK MultiWii 328P) from Android is described in this post.
Next, the attempt to setup WiFi communication again with Arduino is detailed in this post.
Transmitter (serial controller)
Most of the applications and programs available for download are focused more on telemetry data than on proper control of the RC model. For MultiWii development I decided to code ARC my own Android app which supports WiFi and Bluetooth communication.
The application, which relies on the MultiWii Serial Protocol (MSP), is in an early stage and can be provisionally downloaded from GitHub
This is exactly what is expected.
MSP_SET_RAW_RC should be sent nearly the same way as a normal TX flow (20ms), in fact at a pace which is compatible with a full remote control.
1s is clearly not enough.