Welcome to Openi6X!

OpenTX for Flysky FS-i6X with a touch of EdgeTX

You can find instructions and videos contributed by fellow early adopters in the RCGroups, Telegram, Discord and Rakish Rc youtube tutorials.

Table of Contents

How to install, upgrade or restore original firmware
Developers guide, how to build
Features
Navigation
Proper shutdown (I see square icon)
USB connection
Powering by 2S Li-Po/Li-ion/18650
Mode 1 and Mode 3 radios
All optional hardware connections
Adjustable backlight level mod
Credits

Features

Comparison with original firmware:

Feature	FlySky i6X	OpenTX i6X
Channels	6/10	16
Mixers	3	32
Models	20	16 / unlimited[1]
Protocols	AFHDS, AFHDS2A, PPM	AFHDS2A, PPM, CRSF
Trainer	PPM	SBUS, PPM
Logical switches	_	✓
Global variables	_	✓
Timers	_	✓
Nicer sounds	_	✓
Use trims as buttons	_	✓
ExpressLRS ready	_	✓
Telemetry mirror	_	✓

^{[1] Unlimited by using USB mass storage mode eeprom backup restore.}

• Protocols:
  • AFHDS2A with SBUS, IBUS and extended SBUS16, IBUS16 - 16 channels modes
  • PPM in/out
  • CRSF with ExpressLRS and Crossfire modules:
    • CRSFshot
    • MEGA Bauds up to 1.8M
    • ExpressLRS V3 configuration (ELRSV3.lua port)
• Telemetry
• Adjustable backlight brightness level (requires basic modification & backlight_mod build)
• Audio tones, alarms and vario sound custom implementation
• DFU bootloader - Start by pushing trims to the center, like regular OpenTX one
• USB Joystick & Storage modes
• AUX Serial port with modes:
  • Telemetry mirror for AFHDS2A and CRSF
  • SBUS Trainer
  • Debug (on DEBUG builds)

Navigation

Key	Function
UP	Up. Scroll values. Hold on main screen for stats.
DOWN	Down. Scroll values. Hold on main screen for telemetry.
OK	Confirm. Hold on main screen for model menu. Short press on main screen for popup menu.
CANCEL	Exit/Back/Cancel.
BIND	Scroll pages right or left (long press), go right in a line. Hold on main screen for general menu.

Shutdown

FlySky FS-i6X don't have a software controlled shutdown button. Do not switch off radio when you see ▫ (small square) icon in top right corner of main screen. It indicates that settings are not yet saved. Wait until it disappears or use "Save all" option from main screen popup menu.

When to use "Save all" option:

• When you don't want to wait until square icon disapper before shutdown.
• With USB connected - when USB is connected then settings are not stored with standard delay.
• To save timers.

USB connection

FlySky FS-i6X don't have a USB VBUS making it impossible to detect USB connection. To connect press OK on main screen and select "USB Connect" (In version 1.8.0 or earlier it's in: Radio Setup -> "USB Detect").
Automatic connection detection can be added by wiring PA15 pad to USB VBUS preferably with a resistor (I have used 1K).

Powering by 2S Li-Po/Li-ion/18650

FlySky i6X is officially rated for up to 6V. Running anything above may damage your radio.

Mode 1 & Mode 3 radios

With Mode 1 & Mode 3 radios you may experience inverted gimbal movement and swapped gimbals on main screen. To fix this swap gimbal connectors (red-white one with black-white one).

All optional hardware connections

PCB Pad	Function
TX2	S.Port (CRSF)
PA9	AUX Serial port TX
PA10	AUX Serial port RX
PA15	USB connection detection
PC13	External module power control (was PC9 up to OpenI6X 1.5.0)
PC9+BL	Wiring those together allows for adjustable backlight

Adjustable backlight level mod

Wire PC9 and BL pads together.

Credits

• Janek (ajjjjjjjj), continues Kuba's and Mariano's work, added sound, USB, ExpressLRS V2/V3 configuration, telemetry mirror, SBUS trainer, new/fixed drivers, ports, bugfixes.
• Mariano (marianomd), continued Kuba's work and made it up to useable condition! Added AFHDS2A, PPM, CRSF.
• Kuba (qba667), started this work and made this project possible, it is forked from his repo.
• Wilhelm (wimalopaan) added 16 channels SBUS16 / IBUS16 modes.
• Tom (tmcadam) fixed AFHDS2A PWM mode selection.
• The internal RF code was taken from the great KotelloRC's erfly6: Er9X for i6 and i6x.
• Some of the internal RF fixes are a result of analysing pascallanger's DIY-Multiprotocol-TX-Module.
• ExpressLRS configurator is based on elrsV2/V3.lua from ExpressLRS.
• Some of the ports are from EdgeTX.
• ADC code taken from OpenGround.
• All the contributors of OpenTX.