Default Sub Hardware Configuration¶
While the Sub firmware is currently being generalized to allow more flexibility, such as RC control, re-arrangement of outputs and inputs, etc., current code is targeted for a specific ROV configuration with the following hardware setup:
Control is via a surface tether from a ground control station via MAVLink commands to the Sub’s autopilot telemetry port, usually employing a joystick and multiple buttons for mode changes and peripheral hardware control. Control functions and autopilot outputs for thrusters and peripheral hardware have specific defaults (see Sub defaults below)
A depth sensor (underwater barometer) is required.
Frame configuration is defaulted to Vectored with 6 thrusters.
Sub Defaults¶
Default frame type is VECTORED
Radio control is disabled via RC_PROTOCOLS = 0 and FLTMODE_CH = 0. Water absorbs radio waves, so RC is generally impractical unless the vehicle is at the surface, or the signal is converted to some other medium in between (e.g. using a tether cable, or acoustic modems).
MAVLink Overrides¶
ArduPilot vehicles normally use radio control (RC) to provide pilot directional control. Since Sub has RC disabled by default, it instead provides directional control with MAVLink RC overrides, and the channel mapping is fixed:
Pilot control |
RC channel override |
|---|---|
Roll |
1 |
Pitch |
0 |
Yaw(Turn) |
3 |
Vertical(Heave) |
2 |
Forward(Surge) |
4 |
Lateral(Sway) |
5 |
Camera Pan |
6 (via AUX function 214 on RC7)* |
Camera Tilt |
7 (via AUX function 213 on RC8)* |
Lights1 |
8 |
Lights2 |
9 |
Video Switch |
10 |
*function depends on type of mount used and can be either angle control or rate control depending on MNT1_RC_RATE parameter (default for SUB is 30 deg/s maximum by default)
Output Assignments¶
The default output assignments are:
Output |
Function |
|---|---|
1 |
Motor1 |
2 |
Motor2 |
3 |
Motor3 |
4 |
Motor4 |
5 |
Motor5 |
6 |
Motor6 |
9 |
RCin9 |
10 |
Mount1 Pitch |