MSH Brain / Ikon setup with EdgeTx and OMPHobby M4

OpenTX / EdgeTX Radios are very popular these days and work very well with the current generation of RC helicopters with Flybarless systems. Although this guide uses the OMPHobby M4 helicopter, it is applicable to any RC helicopter with a Flybarless system.

Receiver Selection

Choosing a reliable receiver is extremely important for a helicopter of this size. We highly recommend the Frsky R-XSR receiver due to the following benefits:

NOTE: R-XSR receiver supports multiple firmware types. For proper operation with Brain2 we need to flash the firmware that supports FPORT interface. To match your Transmitter you will need either ACCST version or ACCESS version. Based on your region you will need either FCC or LBT. You can download the latest firmware from https://www.frsky-rc.com/r-xsr/

Transmitter type	Europe	USA
cc2500/4-in-1 multi-module	RXSR_ACCST_2.1.1_Fport_LBT.frk	RXSR_ACCST_2.1.1_Fport_FCC.frk
Frsky ACCESS	RXSR_ACCESS_2.1.7.frsk	RXSR_ACCESS_2.1.7.frsk

There are multiple ways to Flash the R-XSR. This is explained here.

Wiring and Mounting

Mount the gyro on the gyro plate using the provided 3M double sided tape. Ensure that Gyro is aligned properly with the helicopter frame. Ensure that USB port is easily accessible. In the above picture USB port is accessible even with the canopy installed.

WARNING: Remove Main and Tail rotor blades while performing the setup. The motor may accidentally start and we don’t want it to cause any injury or damage.

EdgeTX Setup and binding

Use the provided EdgeTX configuration file as a starting point.

Download TX16S EdgeTX configuration file for Brain2 with R-XSR.

Download Zorro EdgeTX configuration file for Brain2 with R-XSR.

To bind to the receiver perform the following steps

• Press and hold F/S button on the receiver while powering up the receiver. All 3 LEDs (red, green, blue) should be lit steady.
• On the Transmitter press MDL->Internal RF

• In Mode, choose MULTI, Frsky X2
• In RF Protocol, choose LBT(EU) for Europe or D16 for elsewhere.

• Select BIND on the Transmitter screen.
• The RED LED on the receiver will start flashing when binding completes.
• Power off and power on the Receiver. Green LED will be constantly lit indicating that receiver is bound to the transmitter.

Brain / Ikon setup

For the first setup we recommend that you use the Windows configuration app and USB port. This is because USB is the most reliable connection for firmware updates and the Windows tool is very informative and easy to use.

The Brain unit gets power over USB port and we can do the firmware update and initial setup even before powering up the helicopter.

Download and install the Windows configuration app. If you do not have a Windows PC we recommend to borrow one from a friend for the initial setup.

After the Windows app is installed. Plug the Brain / Ikon to the Windows PC with a USB cable. Start the app and follow the instructions on the App.

Gyro Orientation

Choose the Orientation to match your setup. In our case it is “Top up, wires front”

Receiver Protocol Selection

In our case we select F.Port INVERTED for the Frsky R-XSR receiver.

Transmitter check

Power up the helicopter. This should provide power to the receiver.

Check that the stick movements match the controls and move all the way from -100% to +100%. In the above image Aileron stick to full right shows 100% on the App.

If they don’t then adjust the channel throws from the MDL->OUTPUTS page

Ensure that Extended Limits is enabled.

Adjust the Min ja Max throw for the respective channel to get full throw from -100 to +100 when you move the respective control stick.

NOTE: Throttle channel will stay at -100 if throttle cut switch (SD tai SF) is active. Even if throttle cut is deactivated, the throttle channel will remain fixed at around -9 as we have programmed a flat throttle curve for all flight modes.

To check that the throttle channel goes from -100 to +100 edit Normal mode throttle curve TCn to be a straight line from -100 to +100

Make sure you are in normal mode (Switch SE away). Now throttle channel should go from -100 to +100 on the app on throttle stick movement.

NOTE: Remember to Reset Normal Mode Throttle (TCn) back to original state.

Servo Setup

Swashplate Setup

This is where we need to do 3 important steps

• Swash plate leveling. See How to level your M4 Helicopter swash plate.
• Set Max Collective pitch. A Pitch gauge is useful for this.
• Set Max Cyclic ring.

Tail rotor setup

Follow the instructions to set midpoint, left throw and right throw.

NOTE: still work in progress. Please check back for more!

Reference Brain2 settings for M4 helicopter

You can use the below setting provided by the M4 helicopter Jonas Wackershauser as a good baseline for your M4 helicopter.

Tip: You can use the advanced menu to quickly set the various parameters.

• Download MSH Brain2 controller settings