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How to use OpenTX Radio: Initial setting of radio

Here, we will introduce initial setting method of OpenTX radio using Jumper T12 Pro as an example.
With radios that use OpenTX, such as FrSky Taranis series, Jumper T16, Jumper T-LITE, RadioMaster TX16S, e.t.c, it seems that almost the same operation is possible. However, key switch assignment / function differs depending on model, and screen / menu configuration differs depending on installed version of OpenTX.
  • Jumper T12 Pro Radio Transmitter Hall Gimbal 2.4G 16CH Open Source Multi-Protocol RC Transmitter

    Jumper USD129.99

    On-board firmware:OpenTX
    Comes with a R1F receiver, no need for you to find another compatible receiver, more convenient for fpv drone zealots like you. JP4-in-1 Multi-protocal module includes. DSM2/X, FrSKY, SFHSS, FlySky, FlySky AFHDS2A, Hubsan and more.

    Buy at Amazon.com(US) Buy at Amazon.co.uk(UK)

Unboxing the radio

PC This is a list of items included in Jumper T12 Pro. On the right side of the body is a battery box that can hold two 18650 type lithium-ion batteries. The left side of the body is a USB cable for connecting to PC. The type of connector is a rare " USB miniB (Amazon.com) " nowadays.
Below the body, from the left, there are parts for changing throttle to center position, parts that improve sound quality(?) of the speaker, And an orange neck strap. Sticker is visible above the body.
Also, apart from this, there is an English quick start guide that folds A4 paper, but it didn't say much.
PC Size comparison with iPhone. Dimention is 158mm x 150mm x 58mm, which fits comfortably in both hands. Weight is 342g.
PC You can insert battery by opening lid on the bottom. White one is connector for battery, which is the same as the barance charging connector for general 2S LiPo batteries ( 3 pin JST-XH connector ). Left of the connector is microSD card slot.
Internal dimensions of battery bay is approximately 63mm wide x 17mm high x 66mm deep. A fairly large battery can be inserted. On the other hand, attached 18650 battery box is barely tall and may be difficult to put in and out.
PC Batteries are sold separately for Jumper T12 Pro. I didn't know the size of the bay, so I chose Hubsan H501S-25 2s 1300mAh LiPo battery , which Amazon recommends with Jumper T12 Pro. Size is about 30mm wide x about 14mm high x about 66mm deep. Fully charge using the balanced charger for 2s LiPo.
Jumper T12 Pro supports DC 5V to 9V as input voltage. Use of 2S LiPo batteries is recommended.

Preparation of microSD card

OpenTX radio uses a microSD card as a data storage area (compatible with SDHC standard). Settings of the radio itself and settings of drone etc. are saved there.
Prepare a blank microSD card. The capacity depends on the amount of icon image and audio data you want to store, but I think 8GB is enough. Format this in FAT32 format on your computer.
MicroSD card (SDXC standard) with a capacity of more than 32GB cannot be formatted in FAT32 using OS standard function. You need to use a free software formatter.
PC The data stored in microSD card in advance can be downloaded from radio manufacturer official website. For Jumper T12 Pro, you can download it by clicking "DOWNLOAD" in "SD CONTENTS" column on Jumper's T12 Pro download page . You can get a file such as "sdcard-128x64-2.3V0025.zip", so unzip it to any folder on your computer.
You can also download OpenTX Companion and others on this page.
PC Then, folders / files shown in this figure will be expanded. Write all of them to the root directory of microSD card and insert it into card slot of radio. In case of Jumper T12 Pro, it is almost empty except for "SOUNDS" folder where audio files are stored, and total amount of data is only about 137MB.

Power on the radio

PC After inserting fully charged battery and microSD card with initial data written in the radio, turn on the power. Press and hold power button in the center of body to turn on.
If either switch or stick is not in initial position, you will see a warning screen like this. Follow the on-screen instructions to set switch or stick to initial position.
PC If you see a screen like this, startup is successful. If microSD card is set correctly, a female voice will say "Welcome to Open TX".

Screen navigation

PC OpenTX screen uses six keys for navigation. Role of each key changes depending on the screen, but in most cases, it has following meanings on Jumper T12 Pro.
[ENTER]: Select / confirm item
[EXIT]: Cancel / Return to previous screen
[UP] [DOWN]: Move cursor up or down / scroll screen
[LEFT] [RIGHT]: Move cursor left or right / switch page
Press and hold [ENTER] [UP] [DOWN] [LEFT] [RIGHT] keys to call up different menu screens.
In addition, assignment / function of these keys differs depending on manufacturer / model.
Main screen
PC Main screen is control screen of currently selected "model". In case of Jumper T12 Pro, you can register 60 aircraft informations from No01 to No60 as "model"s and switch between them for control. Below the model name, remaining battery level of radio is displayed. Numbers listed below are stick position information (-100 to +100).
There are 4 main screens in total, which can be switched with [UP] and [DOWN] keys. Also, on screen where horizontal line and dotted line are displayed in the center, you can switch display contents with [LEFT] and [RIGHT] keys. You can also display telemetry information from aircraft on main screen (use DISPLAY setting).
PC You can bring up this menu by clicking [ENTER] key on main screen. You can move cursor with [UP] and [DOWN] keys, and click [ENTER] key again to select them. Press [EXIT] key to return to main screen.
[Reset]: If you select this, a submenu will be displayed, and you can reset timer and telemetry used during maneuvering individually. Select "Flight" in submenu to reset all timers and telemetry at once.
[Statistics]: Usage status of radio so far is displayed.
[About]: You can see the credits of OpenTX developers. You can scroll with [UP] and [DOWN] keys.

MODEL menu

Press and hold [ENTER] or [RIGHT] key on main screen to enter MODEL menu. With [LEFT] and [RIGHT] keys, you can switch between following 13 types of pages related to "model" of aircraft to be operated. Press [EXIT] key to return to main screen.
To fly a new aircraft, set up a new "model" by entering each of screens below. Of these, the minimum required screens for operating Tiny Whoops are only three screens: SETUP, INPUTS, and MIXES. For how to set the "model", see How to use OpenTX Radio: Bind with drone, model creation, test flight .
MODEL menu
01MODELSELSelect model you want to control from models (aircraft) stored in the radio.
02SETUPThis screen is for basic settings of selected model. You can also select communication protocol with aircraft and bind it from this screen.
03HELI SETUPSetting screen for radio-controlled helicopters. Not used on drones or other aircraft.
04FLIGHT MODESPrepare multiple function assignments / settings (flight mode) to sticks and switches, and use them when you want to switch during maneuvering. It can be used for applications such as preparing settings for acrobatics and low-speed stable flight and switching during maneuvering.
05INPUTSThis screen lists input devices used for maneuvering. It can also be thought of as a screen that assigns input devices such as sticks, switches, and LOGICAL SWITCHES mounted on the radio to virtual channels defined inside OpenTX.
It is also possible to define multiple weights (reaction intensity) and curves (reaction curve) for one device and set them to switch. You can also split movement of one stick in half from the center and assign it to two different virtual channels.
06MIXESThis screen defines which input device (virtual channel) defined on INPUTS screen is transmitted to which physical channel of receiver (aircraft).
The output values of multiple virtual channels can be mixed at a specific ratio (weight) to control one physical channel, or one virtual channel can control multiple physical channels at the same time. Weights, curves, etc. can be set here as well.
07OUTPUTSThis screen is for adjusting maximum value, minimum value of pulse length, trim, etc. for each physical channel defined on MIXES screen. Adjust logical control signal to fit actual servo range of motion. You can also reverse direction of rotation of servo.
08CURVESIt is a screen to define user's own custom curves (reaction curve). You can define 32 types of custom curves from CV1 to CV32. Defined curves are used on INPUTS screen and MIXES screen.
09LOGICAL SWITCHESThis screen defines a virtual switch that takes two values, TRUE and FALSE. This switch automatically turns ON / OFF according to various specified conditions and can be used as a trigger to call other functions. 64 types of logical switches L01 to L64 can be defined.
10SPECIAL FUNCTIONSThis screen assigns various functions to toggle switches and logical switches of radio. Settings here are saved for each model.
11CUSTOM SCRIPTSThis is the screen to define LUA script.
12TELEMETRYMake settings related to telemetry data obtained from receiver. You can adjust display of power supply voltage of receiver, and adjust signal strength to notify signal lost alarm.
13DISPLAYScreen to set which of the telemetry data from aircraft is displayed on which part of four main screens of radio.

RADIO menu

Press and hold [LEFT] key on main screen to enter RADIO menu. With [LEFT] and [RIGHT] keys, you can switch between following 7 types of pages related to radio itself. Press [EXIT] key to return to main screen.
(In case of version 2.3.10.)
RADIO menu
01TOOLSCall LUA script stored in [SCRIPTS]-[TOOLS] folder of microSD card.
02SD-HC CARDYou can check contents (list of folders and files) of microSD card inserted in radio like Windows Explorer / Mac Finder.
03RADIO SETUPSet the radio.
04GLOBAL FUNCTIONSThis screen assigns various functions to toggle switches and logical switches of radio. Settings here are common to all models.
05TRAINERWhen using radio as a trainer (teacher) mode, set signals (channel assignment and weight) sent from student's radio. In trainer mode, student's radio connects to trainer's radio and trainer's radio connects to aircraft. Trainer can assist student in maneuvering.
06HARDWAREYou can refer to hardware related information of radio. You can calibrate sticks and battery.
07VERSIONShows the version of OpenTX installed on radio.
If you press and hold [UP] key on main screen, same screen as [ENTER]-[Statistics] will be displayed.
Press and hold [DOWN] key on main screen to display Telemetry screen.

OpenTX information site

You can read the detailed usage of each screen below.

Date / time / battery voltage range setting

PC First of all, let's set today's Date, Time, maximum voltage and minimum voltage (Batt. Range) of battery you use in radio.
Jumper T12 Pro is compatible with a variety of batteries such as DC 5V-9V alkaline, NiCd, NiMH batteries, 18650 type lithium ion batteries, and 2s LiPo batteries. If you set maximum and minimum voltage of battery you use, battery level graph on main screen will be displayed correctly.
For 2s LiPo battery and two 18650s, 6.0-8.4 is fine.
On the main screen, press and hold [LEFT] key to open RADIO SETUP screen, use [UP] [DOWN] [LEFT] [RIGHT] keys to select value you want to change, and press [ENTER] to enter edit mode. If you press [UP] [DOWN] keys there, the value will change. Press [ENTER] again to confirm the value and exit edit mode.

Battery calibration

PC Calibrate battery so that radio can correctly read voltage of set battery. First, check current battery voltage using a measuring device such as a tester.
If you have a lipo battery checker & balancer (Amazon.com) like the one shown in this picture, you can use it to read voltage.
PC Return the battery whose voltage has been checked to radio and power on it. Then, in order to minimize the power consumption of radio, turn off communication unit built into radio. Press and hold [ENTER] or [RIGHT] key on main screen to enter MODEL menu.
PC Open SETUP screen with [LEFT] and [RIGHT] keys. Use [DOWN] keys to scroll screen, select Internal RF Mode, press [ENTER] to enter edit mode, and press [UP] [DOWN] keys to turn it off. Press [ENTER] to confirm the value and exit edit mode.
If External RF is not turned off, turn it off as well.
PC Press [EXIT] key to return to main screen, and press and hold [LEFT] key to enter RADIO menu. Use [LEFT] and [RIGHT] keys to open HARDWARE screen, and use [UP] and [DOWN] keys to select Batt. Calib. Press [ENTER] to enter edit mode and press [UP] [DOWN] keys to change the value. Make sure it is closest to current battery voltage you checked first. Press [ENTER] to confirm the value and exit edit mode.
Go back to main screen and check battery voltage display has been corrected. Also, if necessary, restore settings of Internal RF and External RF that were once turned off.

Stick calibration

Before using radio, calibrate sticks and dials (Pot: Potentiometer) so that they can be read correctly.
PC Press and hold [LEFT] key on main screen to enter RADIO menu, open HARDWARE screen with [LEFT] and [RIGHT] keys, move cursor to [Calibration], and press [ENTER].
PC Status of sticks and dials (Pot) is displayed on the screen. Press [ENTER].
PC Then you will see a screen like this. Center all sticks and dials (Pot) and press ENTER. In case of Jumper T12 Pro, there is one dial (Pot) on each side of the body.
PC Next, you will see a screen like this. Move all sticks and dials (Pot) all the way up, down, left and right. The on-screen display, which was initially rattling, can now be followed smoothly by moving sticks and dials (Pot) all the way. Then press [ENTER].
PC You will be returned to this screen. This completes the calibration. Press [EXIT] key twice to return to main screen.
PC Calibrating a stick is not "once first, then it's done". Normally, radio stick has a pulse length in the range of about ± 0.5 μsec when centered. However, one of the axes may suddenly shift to a value of about ± 1.0 μsec or more one day. When this happens, drone suddenly doesn't fly the way you want, or you feel like you became not good at maneuvering. Check the value in the center of the stick every time you turn on the radio, and calibrate if the center is off.

Other settings

At this point, minimum initial settings for OpenTX radio have been completed. After that, let's look at each item on RADIO - RADIO SETUP screen. Press and hold [LEFT] key on main screen to enter RADIO menu and open RADIO SETUP screen.
Please change "Country code" in following items according to area where you live. Others can be set as you like.
The value in "Initial value" column is initial value for Jumper T12 Pro (OpenTX Version 2.3.4 2019-12-27 17:12:20).
Sound menu
menufunctionInitial value
ModeSpecifies how to play sound. [All]: Play all sounds. [NoKey]: Play with all but key operations. [Alarm]: Only play warning sound. [Quiet]: No sound.NoKey
VolumeSpecify master volume. Specifies maximum volume of Beep, Wav, and Bg sound specified below.(center)
Beep VolumeSpecifies volume of beep sound.(center)
Beep LengthSpecifies beep ringing time.(center)
Beep PitchSpecifies pitch of beep. Specify by adding frequency to the base value. It can be specified in 15Hz units and can be set in the range of 0 to + 300Hz.+0Hz
Wav VolumeSpecifies volume of Wav sound (talking voice). The ringing timing of Wav is specified using Play Track option on SPECIAL FUNCTIONS screen.(about 90%)
Bg VolumeSpecify volume of BGM. The background music to play is specified using Background Music option on SPECIAL FUNCTIONS screen.(about 75%)
Variometer menu
menufunctionInitial value
VolumeSpecifies volume of Variometer alert sound.(center)
Pitch zeroPitch (Hz) of beep that is played when vertical velocity is between Sink Min and Climb Min defined on Telemetry screen. It can be set in the range of 300Hz to 1100Hz.700Hz
Pitch maxPitch at maximum vertical velocity defined by Climb Max on Telemetry screen. It can be set in the range of 700Hz to 2900Hz. As the rate of increase increases, the beep frequency increases linearly from the value specified in [Pitch zero] to the maximum value specified here. This maximum value must be greater than value specified by [Pitch zero].1700Hz
Repeat zeroSpecifies beep ringing interval in milliseconds. It can be specified in the range of 200 (5 beeps / sec) to 1000 (1 beep / sec).500ms
Here, specify how to play warning sound when aircraft has a Variometer that detects its ascent and descent. Variometers are used in radio-controlled gliders mainly.
Haptic menu
menufunctionInitial value
ModeSpecify how to vibrate radio. [All]: Vibrates when all sounds are played. [NoKey]: Vibrates with everything except key operation. [Alarm]: Only warning sound vibrates. [Quiet]: Does not vibrate.NoKey
LengthSpecifies length of vibration.(center)
StrengthSpecifies strength of vibration.(center)
Contrast menu
menufunctionInitial value
ContrastSpecifies screen contrast. For Jumper T12 Pro, specify in the range of 10 to 30.20
Alarms menu
menufunctionInitial value
Battery LowSpecifies alarm sound when battery of radio is low. Alarm sounds when voltage drops to the value specified here.6.5V
InactivitySpecifies an alarm when radio is not operated for a long time. If you do not operate for the time (in minutes) specified here, the alarm will sound. If you specify zero, alarm will not sound.10 minutes
Memory LowSpecifies whether to sound an alarm when memory becomes insufficient when using LUA script.ON
Sound OffSpecifies whether to sound an alarm when all sounds are accidentally turned off.OFF
Rssi ShutdownSpecifies whether to sound an alarm when RSSI (Receiver Signal Strength Indicator) signal from the aircraft is lost while radio and aircraft are connected.ON
Backlight settings
menufunctionInitial value
ModeSpecify conditions for turning on backlight. [OFF]: Always turns off. [Keys]: Lights when you push any of 6 screen operation keys. [Ctrl]: Lights when sticks or switches is operated. [Both]: Lights when screen operation key, sticks or switches is operated. [ON]: Always lit.Both
DurationSpecify lighting time of backlight in "seconds".10 seconds
BrightnessSpecify brightness of backlight in the range of 0 to 100.100
AlarmSpecifies whether to turn on backlight when an alarm occurs.OFF
Various time settings
menufunctionInitial value
Splash ScreenSpecify time to display startup screen (OpenTX logo screen in Initial value) in "seconds".4 seconds
Pwr On delaySpecifies long press time of power button required to turn on power of radio. It can be specified in 0 to 3 seconds. If you specify 0 seconds, it will start instantly when you push power button.2 seconds
Pwr Off delaySpecifies long press time of power button required to turn off power of radio. It can be specified in 0 to 3 seconds. If you specify 0 seconds, it will stop instantly when you push power button.2 seconds
GPS settings
menufunctionInitial value
Time zoneFor radios equipped with GPS receivers, specify time zone required to use GPS by difference (integer from -12 to 12) from UTC (Coordinated Universal Time).0
Adjust RTCFor radios equipped with GPS receivers, specify whether to correct clock of radio with information received from GPS satellites.OFF
GPS CoordsFor radios equipped with GPS receivers, specify GPS coordinate display format. [DMS]: Displayed in Degree Minutes Second. [NMEA]: Displayed in minutes by degrees and decimal points (NMEA: National Marine Electronics Association format)DMS
Various environment settings
menufunctionInitial value
Country codeSelect region where you want to use the radio from US (USA), JP (Japan), and EU (Europe). This information is used to make built-in transmitter module comply with local radio regulations.US
Voice languageSelect language of audio to play with alarms, etc. Specify which folder to use under "SOUNDS" folder on microSD card.English
UnitsSelect unit used for telemetry display from Metric or Imperial.Metric
Play delaySpecifies time, in milliseconds, before playing audio assigned to center of three-position switch. If this is too short, the audio in center position will also be played when three position switch is switched from end to end.150msec
USB ModeSpecifies operation when radio is connected to PC with a USB cable. [Joystick]: Operates as a "USB joystick (HID device)". [Storage]: Acts as a "USB storage device". From PC, you can access microSD card built into radio and EEPROM that stores model information. [Ask]: Screen will give you a choice of which mode to work with.Ask
Various channel settings
menufunctionInitial value
RX channel ordWhen creating a new model, specify order in which Aileron, Elevator, Throttle, and Rudder are assigned to virtual channels 1 to 4 on INPUTS screen. You don't have to worry too much about this setting as you can freely change assignment to physical channel on MIXES screen. Also, changing this will not affect models that have already been created.AETR
ModeSelect stick assignment, from 1 to 4. It seems that mode 2 is often used by drone pilots and RC users in the United States, and mode 1 is often used by RC users in Europe and Japan. Drone products and instructions are based on Mode 2. If you are just starting out, we recommend practicing in mode 2.1 or 2
(Select at the time of purchase)

Back up EEPROM

Radio that uses OpenTX has a "Flash memory" that stores firmware and boot loader, and an "EEPROM (Electrically Erasable Programmable Read-Only Memory) that stores model information and various setting information inside. Contents of the EEPROM can be backed up to built-in microSD card in RADIO menu.
PC Press and hold [LEFT] key on main screen to enter RADIO menu, open HARDWARE screen with [LEFT] [RIGHT] keys, and scroll to the bottom of the screen with [DOWN] keys to see this screen. Select [EEPROM backup] and press [ENTER] key ...
PC Then it will be backed up instantly.
PC Open SD-HC CARD screen and select [EEPROM] folder, and you will see backup file like this. The backup file is a small file of several tens of kilobytes in .bin format.
The collected backup can be written back to radio using OpenTX Companion app on your PC. Of course, you can also back up EEPROM with OpenTX Companion.

OpenTX firmware update

OpenTX radio can update firmware, multi-protocol module (transmitter), and boot loader. Newest firmware is released every few months, and updates may make new protocols available.
Also, if transmitter firmware is factory default, it may not be possible to bind to aircraft released after that. If you cannot bind, you may be able to solve it by updating to the latest version.
See below for detailed instructions on updating the firmware.

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