Advanced Functions

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The STorM32 board provides many user features. Many of them can be activated or controlled by an input signal, and are accessible as so-called functions (see Inputs and Functions). Other features are accessible via specific parameter fields, or the [Tools] menu.

Second IMU Support

One of the major features of the STorM32 controller is its support of a second imu, providing unmatched performance figures. For a detailed account see the article on Using a 2nd IMU.

Lipo Saver

The parameter Low Voltage Limit in the [Main] tab allows to activate a lipo saver. When the battery voltage falls below the specified voltage per cell, the motors are disabled to minimize current draw. This condition is signaled also by the fast blinking green and red led. The board needs to be re-powered or reset to resume normal operation.

Comment: Lipo batteries may be safely discharged down to 3.0 V/cell, under load.
Comment: The lipo cell number is determined automatically by the firmware when a battery is connected to the board. Connecting discharged batteries may lead to incorrect cell number determination.

Voltage Correction

The parameter Voltage Correction in the [Main] tab allows to activate the voltage correction mechanism.

This mechanism attempts to compensate the effects of a (slowly) varying battery voltage on the PID controller tuning. It does it by modifying the actual motor power. i.e. [Vmax] values proportionally to the voltage change. The proportionality factor is given by the parameter [Voltage Correction]. For instance, with a [Voltage Correction] of 100%, a drop in the battery voltage by 25% leads to an increase of the actually used Vmax value by 25%. With a [Voltage Correction] of 50%, a voltage drop by 25% leads to a 12.5% increase in Vmax, and so on.

The mechanism can significantly reduce the dependence of the gimbal performance on the battery voltage, compensating for the slow voltage drop with time when running from a battery. It is not designed to handle short-time power burst due to e.g. sudden aggressive flight maneuvers. It also cannot accomplish what could be achieved with a truly constant (regulated) voltage.


The parameter Beep with Motors in the [Setup] tab allows to activate the emission of beeps by the motors upon certain events. Two settings are available:

  • "basic"
  • "full"

Comment: The beeps are audible only when the motors are enabled. Hence, beeps are e.g. not heard when the board is powered only by the USB.


This function can be activated and its trigger source be specified by the parameter Standby in the [Functions] tab.

When in normal operation, it will disable the motors. When in standby mode, it will enable the motors and do a quick relevel. It will not go through the full initialization process and e.g. will not do a gyro calibration. Hence the standby function allows to quickly resume operation. It also means however that if the camera position has been heavily changed or the system has been put into other unfavorable conditions, that the relevel may fail.

Re-center Camera

This function can be activated and its trigger source be specified by the parameter Re-center Camera in the [Functions] tab.

It will recenter the camera, i.e. will undo any change in camera position due to a manual control signal. For the yaw axis, it does not undo the cumulative center position changes when switching between hold and pan mode.

IR Camera Remote Control

This function can be activated and its trigger source be specified by the parameter IR Camera Control in the [Functions] tab. The camera type is selected by the parameter Camera Model.

It provides a remote control of the shutter and video functions of the camera (if available). For remote controlling Sony Nex and Canon cameras one can connect a IR led directly to the IR port (see Pins and Connectors). Panasonic cameras can be remote controlled by adding a small piece of hardware, as described here.

The camera shutter and video on/off can be adjusted via these fields in the [Functions] tab:

  • IR Camera Setting #1
  • IR Camera Setting #2
  • Time Interval

Pwm Out

This function needs to be enabled via the parameter Pwm Out Configuration in the [setup] tab, and the PWM output format and frequency be specified. Then it can be activated and its trigger source be specified by the parameter Pwm Out Control in the [Functions] tab.

When activated the PWM signal is output on the pin RC-1. The input channel "Rc-1" yields zero value.

The details of the signal and its behavior can be fine-tuned via these fields the [Functions] tab:

  • Pwm Out Mid
  • Pwm Out Min
  • Pwm Out Max
  • Pwm Out Speed Limit


The innovative concept of on-board scripts, invented by the STorM32 project, allows to modify the controller's behavior and accomplish even complicated tasks. For the details see the article on the STorM32 Scripts.

Some example script files (extension .scr) are available in the firmware folder, which should be sufficiently self-explanatory.

Motion Control

The STorM32 controller provides a rich set of commands for remote controlling the camera. These commands can be send to the board via any of the serial ports (USB, UART, Bluetooth). A very convenient method to make use of that are motion control scripts. A typical example application would be a pano, i.e. shooting a sequence of photos which are later stitched together to a large panorama view.

Some example motion control script files (extension .mcs) are available in the firmware folder, which should be self explanatory enough to use them.

The following commands are currently (firmware v0.68) possible:

  • SetParameter()
  • SetAngle()
  • DoCamera()
  • RecenterCamera()
  • SetPwmOut()
  • Wait()
  • TextOut()

The motion control programming language is in fact just native Perl, so you can do anything you want and is possible with a full-fledged scripting language. You may use all control structures, define variables and even your own functions, as needed.


The STorM32 controller supports MAVLink.

For enabling it, open the [Expert Tool] window, which is accessible via the [Tools] menu:

  • Mavlink Configuration: Set to "emit heartbeat" to activate the emission of a heartbeat message.
  • Mavlink System ID: Set the System ID of the STorM32 controller (default = 71).
  • Mavlink Component ID: Set the Component ID of the STorM32 controller (default = 67).

For the supported MAVLink messages, see Serial Communication: Mavlink Communication and Serial Communication: Comments to STorM32 specific Mavlink commands.

Currently, the STorM32's Mavlink capabilities are exploited (to some extend) only by the 32-bit ArduPilot flight controllers. See also