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 [GUI: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 [GUI: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. In that calculation the maximum cell voltage is assumed to be 4.2 V. Connecting discharged batteries may lead to incorrect cell number determination. Also, using cells with maximal cell voltage very different from 4.2 V may confuse the mechanism.

Comment: The voltage can be calibrated by adjusting the ADC Calibration parameter in the [GUI:Expert Tool] window.

Voltage Correction

The parameter Voltage Correction in the [GUI: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.

Comment: The voltage can be calibrated by adjusting the ADC Calibration parameter in the [GUI:Expert Tool] window.

Beeps

The parameter Beep with Motors in the [GUI: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.

Standby

This function can be activated and its trigger source be specified by the parameter Standby in the [GUI: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.

For handheld gimbals it is suggested to use the fast startup mode by setting Startup Mode to “fast” in the [GUI:Setup] tab. In this mode, the gyro calibration is also skipped but it reduces environment limitations and the gimbal is operational a few seconds faster. Before resuming from standby, user should check that the camera is aligned properly with respect to the gimbal support; it should point forward to within few degrees. This operation mode is only suitable for taking short videos. For taking long videos a good gyro calibration is unavoidable.

Re-center Camera

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

Camera Remote Control

The STorM32 provides dedicated and rich possibilities to control the operation of the camera.

This function provides a remote control of the shutter and video functions of the camera, but also unprecedented features going far beyond these basic operations.

For instance, the NT Camera concept, available via NT IMU modules, provides a much richer set of options for controlling the camera, and increases the range of supported cameras to models like the Gitup Git2, Runcam Split or GoPro Hero5.

For more details, please see the article NT Camera.

The STorM32 also has integrated dedicated MAVLink camera support, namely a full implementation of the MAVLink camera micro service, which in fact provides the coolest camera control features, see MAVLink Communication.

Pwm Out

This function needs to be enabled via the parameter Pwm Out Configuration in the [GUI: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 [GUI:Functions] tab.

When activated the PWM signal is output on the pin RC-1. The input channel “Rc-1” yields zero value. The PWM signal is also output on a NT Camera module, if available.

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

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

Scripts

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.

MAVLink

The STorM32 controller supports MAVLink. It in fact supports a rich set of MAVLink messages and features, as well as the MAVLink 2 protocol, and might be by far the most integrated MAVLink capable gimbal controller available. Moreover, it actually integrates two MAVLink components, called MAVLink Gimbal and MAVLink Camera.

For further information and details, please see the article MAVLink Communication.

The STorM32's MAVLink capabilities are exploited (to some extend, and possibly with some flaws) by the ArduPilot flight controllers. See also

NT Logger

The STorM32 controller supports real-time logging of quite many data onto micro SD cards, by attaching a NT Logger module to the NT bus.

For enabling and fine-adjusting the data logging, open the [GUI:Expert Tool] window, which is accessible via the [GUI:Tools] menu, and set the NT Logging parameter.

For the details see the article NT Data Logger.

STorM32 Link

A serial connection can be used to transfer dedicated data from the flight controller to the STorM32 controller in order to help it achieving better stabilization, and hence better videos. For instance, yaw drift can be corrected, horizon shifts in high-speed turns removed, or smoother pans achieved.

This set of functions is called the STorM32-Link, please see the article STorM32-Link.

Encoder

The STorM32 supports using encoders, which is then called T-STorM32.

For more details see the articles What is T-STorM32 about? and Getting Started with T-STorM32.

Prearm Checks

The STorM32 provides a mechanism to check various conditions at startup, and to check if they all have been passed or not. This is especially useful for flying vehicles.

For more details see the article Prearm Checks.

Filter

The STorM32 provides a filter section to filter the gyro, accelerometer, encoder, and motor control data, using low-pass filters and notch/band-cut filters.

For more details see the article Filters.

Servo Motor Mode

The STorM32 provides a servo motor mode, which comes in handy when the motor should be controlled but there should be no stabilization. The mode can also be used to realize robotics type application.

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