Thread Tools
This thread is privately moderated by GottaZoom, who may elect to delete unwanted replies.
Sep 26, 2018, 06:55 PM
Up! Up! And Away!
GottaZoom's Avatar
Thread OP

Jumper T12 Multi-Protocol TX - with branched OpenTX firmware

Jumper T12 Multi-Protocol Radio Control System - branched from OpenTX (12 min 11 sec)

This video is just a quick intro of the Jumper T12. My hope is this blog entry will become both a useful introduction and a resource for people who buy the T12. Please post questions or requests on the RCGroups T12 thread linked below.

Note: Banggood provides a product sample and lets reviewers post their own findings and opinions – this is a good thing for all of us. They provide an ID for each reviewer, so they can track which reviews people are motivated to check their website . When you find a review helpful, please consider voting your thanks to Banggood with a click to their website. I’m not going to get a fee for that. Your cost is the same if you decide to buy.

What is it?

The T12 is a radio control transmitter designed as 2 parts - a system.

The first large part is a controller that runs a lightly modified version of OpenTX firmware inside a small case that has the usual sticks and switches/pots, plus a bay like one formerly offered with JR brand radios (and a few other radios still available today). Control commands are sent by wire/pins to an external radio frequency (RF) module only when it is plugged into the bay.

The second part is a removable module in the bay that has its own processor running separate multi-protocol module (MPM) firmware that takes the controller inputs and converts them to your chosen protocol - one out of many different receiver varieties. It passes those converted signals on to one of 4 different transmitter chips and then eventually on out via antenna to be received by a receiver that uses the protocol selected in the controller's model settings.

Jumper originally introduced this to be an Open-TX radio, but for now this radio firmware is a branch/fork off Open TX 2.2.2 for the QX7. The fork is called JumperTX and it looks like Open-TX because that is its origin.

What are its important points –Pro, Neutral, & Con?


- The price is attractive (about $83 as review written) With the included multi-protocol module.

- Sticks are smooth and feel very good, confirmed by several other reviews seen to date (not hall effect). The default mode 2 setup without calibration was very comfortable for my first flight with a small quad. For those interested, there is at least 1 video on YouTube for changing over to mode 1.

- 16 channels at that same, low price – different protocols/receivers may offer fewer channels

- JR bay and module allows the parts to be separated and used with other compatible devices. This provides for an easy replacement for a physical parts upgrade or replacement; and it allows gear to be changed for models using ultra long range or race gear

- External USB ports for both parts: controller and MPM

- More protocol choices with MPM updates (planning to do a separate post on that).

- Controller USB port along with Open-TX firmware allows the radio to be used with simulators. Battery use is also extended by setting up a simulator model with RF selections OFF. I used the wizard to set up a Simulate model – works great with ClearviewSE (free, or purchase optional models).

- ERSky9x firmware is available (Open-TX is based in part on work by the ersky9x developer) and some report it “has a more hierarchical menu structure”

- Crossfire compatible (not tested, but demonstrated by Josh B.)

- Telemetry info display and logging, with capable receivers & sensors


- The Open-TX firmware base will be seen by some people as straight-forward to learn, extremely flexible and powerful. Others will find all the options/features and flexibility is perhaps overwhelming to them. My view is that one can start off simply by learning only a few setup basics, and then decide to either stop or go on from that point.

- The T12’s size is small and handy to use and pack – it is only about an ounce heavier than a comparably equipped Xlite. Others will find issues with the sticks and layout, particularly those who want their hand to be more forward on the TX where switches would be a problem. I use my thumb on the left stick and pinch on the right AND I tend to tilt the top of a TX down and away from me.

- LUA app/scripts can be very helpful features. When they work they are great, but when the app and the firmware and hardware are not all in sync they can frustrate.

- Choice of power chemistry (alkaline, NiMH, or lithium) is provided, and I originally saw this as Pro point. However, a couple recent posts have suggested 4 AA/NiMH cells may not supply enough voltage for some radios/users. I believe Jumper provides the option but recommends 2S power.


- Because this is not be an Open-TX family radio, customizing build options is not available and the path to future features is unknown at this time.

- When new protocols are flashed to the MPM, JumperTX will not display them unless it is updated. Using the custom protocol workaround is one option. Ersky9x firmware and its multi.txt file updates is an alternative to this and the problem above.

- The controller lacks the probable better reliability of an internally and permanently wired radio section. Menu choices are present, but connections were reportedly not implemented.

- The case lacks any charging provision inside or externally connected to the case.

- Pot dial rattle is very annoying when the TX is moved around.

What else will you need?

- Batteries, 4xAA size or a 2S pack with balance connector that fits inside the compartment

- Micro SD card for optional features to be used

- Good reference links to get started, use many optional features, and to continue learning to harness the power and flexibility coming from Open-TX

Where can I get helpful info?

Unfortunately, for some time there will be very few T12-specific resources that will cover every available feature. Most people will never learn or use all of the features. The button interface and a few other features are different from Open-TX radios, but resources for other radios and OTX versions will be similar to how the T12 works.

For many things I want to learn, I use Google and the subject or term in the OTX menu and then look at some of the different Open-T-X sources I’ve seen before (especially But it’s also helpful to choose from your own list of resources to help with your OTX experience. When that fails me, I’ll turn to RCGroups searches and thread for OTX or my radio.

- OTX 2.2.2 thread

- T12 thread

- - Written manual available from Aloft Hobbies

- Online guide/manual

- Online self teaching lessons

- Module firmware documentation

- Protocols available, including how they work

- Workaround for protocols/subs not showing in the radio menu
(Use Custom for protocol name plus give protocol and subtypes from MPM instructions)

- Protocol used for known models

- SD card contents for optional features
(scroll down to SD card contents from OTX project)

Initial Setup

- Optional: prepare SD card using Open-TX card contents and or Jumper TX files

- Optional: install OpenTX Companion program and read firmware from radio to save on disk/SD card

- Insert micro SD card (I used an old 2GB card)

- Insert chosen power source using AA tray or 2S balance connector (note the compartment has a strange shape inside but 18650s do not fit)

- Power on radio & start learning the button menu interface

- Adjust radio settings

- Date & time needs to be set. Good practice to learn the button interface, but you’ll want to change battery warning first if using AA cells.

- Adjust battery graph range & warning, as needed for power source chemistry. Default settings will work with no changes for a 2S lithium pack. My preference is to use 6.4v for empty and 8.4v for full. Battery low warning set a little more conservative at 6.6 volts.
(AA, NiMH, & Lithium could each have different voltage settings)

- Confirm channel order is AETR, which is the correct default for the MPM unless you change the module’s firmware.

- Recommended: Change switch H from Toggle to 2-position in Hardware screen so that switch H will have a default switch-warning.

- Setting up the first model was a breeze with the wizard. I started with a B03 quad and did not even have to reverse any control.

- Binding the model is generally easy. Power up the model and then select the bind option in the Model Setup Screen next to the Receiver Number. Most receivers I use remember the MPM TX ID - some will not and they may have to follow the bind process each use. After binding, the normal process is to power up the radio set to the model being used, then power up the model.

- Test & alter model settings, as needed - my B03 needed no changes. My Dart Quad needed aileron and rudder to be reversed in the Outputs screen. Highlight the channel/output, edit, and then select inverse for servo direction. Finally, you can set up switches and other options.

X7 to T12 -Things to Watch

- Battery warning will go off if you start with AA cells, it’s pre-set for ~2S. Went with 2S until we see or test range with both power sources. Likely not to be much difference, but I had 2S 1000mAh packs on hand. Some have reported 1300 packs working, but mine did not fit. Will make or buy an adapter to minimize unplugging at the radio connector to minimize wear from charging.

- Switch H is a momentary toggle on the X7, it is a 2-position on the T12. Important to change so that there will be a switch warning, especially if switch is used for throttle cut.

- The new model wizard defaults to internal RF, so that needs to be turned OFF and External set up with MULTI and selected Protocol (and sub-type, as needed). Not yet sure if the wizard file will be edited to change the default.

- Some modules like XJT and R9 may not work completely correctly due to lack of “heartbeat” signal on module pin 2 (Source: Mike B.).

- Switch F from the X7 firmware is switch G on the T12, Companion won’t know this

- Delta mix in wizard did not work in my first use. I may have reversed the servo connections, so this needs more testing.

- At this time it is unclear what updates will be available in the future for this radio from Jumper or OTX. ERSky9X firmware has a great history of updates. Many people have suggested ersky9x is easier to use than Open-TX, too. The one caution with ersky9x is that the newer FrSky X & S receivers may not work. Also, it is possible some options in the _config.H file of the MPM firmware may need to be revised.

- As I said earlier, I recommend those new to OTX start simply and initially only learn the things you absolutely need to fly a very simple model. Additional features can then be learned one by one, starting with secondary necessities and then moving onto advanced and fun options.
Last edited by GottaZoom; Sep 30, 2018 at 09:55 PM.
Sign up now
to remove ads between posts
Sep 26, 2018, 06:56 PM
Up! Up! And Away!
GottaZoom's Avatar
Thread OP
Range test comparison info. I am considering my T12 with JP4in1 FrSky D16 protocol performance roughly equivalent to my Taranis X7 internal RF module. Here's why:

1. Today, my JP4in1 passed full power distance tests running the FrSky D16 protocol (in T12 controller on 2S power) while connected to an S6R receiver mounted in a Delta Ray. I have not yet tested fine tuning to see if I should use an offset. RSSI was 48.

By comparison, before mounting the RX we tested it with the X7's internal XJT and while I did not record the RSSI at that time, there were no telemetry warning (critical set at FrSky default of 45),

My bud and I have been using a stretch of road near his home for full power range tests over several years. This is our benchmark and it has worked well for us when setting up new planes. Otherwise, we use 30 paces in range test mode when at a field.

We've done tests with DX4, DX6i, 2 Flysky T6s, Turnigy i10, FrSky QX7, 2 Banggood Atmel modules, and a couple ORX DIY modules and mostly Delta Ray models with the oem receiver, or a receiver driving servos (AFHDS, AFHDS2A, D8, & D16 protocols). The distance per Google maps is just over 1/2 mile (810 meters) with the end of the road being slightly uphill (and furthest distance for the model or receiver).

So far, we've had 3 fails in all of our tests - A DX6i that was returned to HH for service, a DX4e (out of service), and an oem DR receiver recovered from an unplanned swim in the lake. We don't use the full power test for smaller Ultra Micro planes (mostly I've used 1S).

For me, this makes 3 different multi-protocol modules where the DSM and/or FrSky performance has passed. The distance is beyond my normal line of sight flying.

2. Low power range testing confirmed the above and is a good approximation of our full power test (or a bit more conservative).

JP4in1 using same setup as described above: Full control at 30 paces, RSSI was 43

Comparison benchmark (same model/RX bound to internal XJT module in FrSky Taranis QX7): Full control at 30 paces, RSSI was 48

There are other advantages of using the low power range test.

- The test can be performed for different power sources (i.e., AAs vs 2S), different protocols, and different receivers.

- The model can be turned to different orientations to see if the battery or some other part of a model might get blocked, or if antenna polarization might be a problem.

- One can also block the TX antenna by turning and using one's body to see the impact of line of sight obstructions at different relative distances.

- Fail safe settings can be safely tested
Last edited by GottaZoom; Nov 02, 2018 at 06:06 PM.
Sep 26, 2018, 06:58 PM
Up! Up! And Away!
GottaZoom's Avatar
Thread OP
Problems and solutions


P=How do I solve the version warning?
S=Unzip and Load the SD card contents onto micro-SD card. Be sure to include the opentx.sdcard.version file when copying all the sub-directories and their contents.

P=How can I backup the firmware that came on the T12?
P=After you install and learn to set up Companion, Select Read/Write menu option and then Select Read Firmware from Radio and select a place to save it on your hard drive. Note: a version was posted here.

P=Flashed T12 with X7 firmware and the screen is upside down and buttons do not work.
S= Don't do that. Flash radio only with JumperTX firmware from website.

P=No warning for switch H being out of position - pots/switches do not show up in menus.
S=Change SH in Hardware page in Radio Settings from Toggle to 2Pos - change 'None' to correct option as needed.

Using Module

P=Trying to bind a DSM RX and it does not seem to work.
S=Use Multi option for Ext RF with the applicable DSM protocol and sub-protocol. (DSM option for Ext RF is for a different module that uses Spektrum radio components.)

P=H501 sub-protocol not showing in OTX menu.
S=Use Custom (2 2) protocol option.

P=Binding difficult or not working correctly (AFHDS2A).
S= Use 2S power. Explanation.

T12 Hardware

P=T12 does not have an S.Port on the bottom like a Taranis X7 for flashing receivers, is there an alternative?
S=OTX provides an alternative to use the JR Bay pins. S6R RX firmware updated with the T12 on 1 Oct 2018.
Last edited by GottaZoom; Oct 03, 2018 at 06:06 PM.
Sep 26, 2018, 07:04 PM
Up! Up! And Away!
GottaZoom's Avatar
Thread OP
Wish List

Originally Posted by Oldgazer
.... A couple of things I would do differently:
1. Relocate the SD Card reader. Because I couldn't get my fingers situated, I dropped the SD card into the case.. Had to take the radio apart.

2. Use a better speaker.
Alternative to relocating card reader could be to change the battery cover to not hinge right in front of the card slot.

More thoughts/adds.

3. Fix the Aux dial rattle, better bushings, maybe? Maybe have one of them with a center detent (center beep isn't too bad).

4. Work with OTX to upgrade the internal RF setting choices and put the 4in1 MPM inside, with outside USB upgrade port working at release, but keep the bay for long range module options.

5. Provide an extension for the 2S connector so that power can be disconnected from the extension. (yeah, I'm struggling to find stuff to add at this point)

6. Adjust battery compartment to fit 2x18650 packs (if possible)

7. Add an audio out option
Last edited by GottaZoom; Sep 26, 2018 at 11:26 PM.
Sep 26, 2018, 11:14 PM
Up! Up! And Away!
GottaZoom's Avatar
Thread OP
Reserved for hardware hacks found
Last edited by GottaZoom; Sep 29, 2018 at 10:16 PM.
Sep 27, 2018, 03:01 AM
Registered User
Great review, GottaZoom. A lot of information.
Sep 27, 2018, 12:37 PM
Up! Up! And Away!
GottaZoom's Avatar
Thread OP
Q=What does it look like to discover sensors?

A=Samples below. When connected to RX the values replace the --- and display in the results screen.
Sep 27, 2018, 06:10 PM
Up! Up! And Away!
GottaZoom's Avatar
Thread OP
Originally Posted by montis
Great review, GottaZoom. A lot of information.
Originally Posted by scousethief
Excellent m8
Thanks X 2!
Last edited by GottaZoom; Sep 28, 2018 at 08:14 PM.
Sep 28, 2018, 06:17 PM
Quad Erat Demonstrandum
scousethief's Avatar
Excellent m8
Sep 28, 2018, 08:24 PM
Oldgazer's Avatar
If you want longer sticks you can use FrSky or Fly Sky stick ends. I snagged some from an old CT-6B..
Sep 29, 2018, 11:32 AM
Oldgazer's Avatar
Originally Posted by GottaZoom
Wish List

Alternative to relocating card reader could be to change the battery cover to not hinge right in front of the card slot.

More thoughts/adds.

3. Fix the Aux dial rattle, better bushings, maybe? Maybe have one of them with a center detent (center beep isn't too bad).

4. Work with OTX to upgrade the internal RF setting choices and put the 4in1 MPM inside, with outside USB upgrade port working at release, but keep the bay for long range module options.

5. Provide an extension for the 2S connector so that power can be disconnected from the extension. (yeah, I'm struggling to find stuff to add at this point)

6. Adjust battery compartment to fit 2x18650 packs (if possible)

7. Add an audio out option
The first part of #4 (Work with OTX) ain't gonna happen. Jumper blew it big time and they are on their own...
Sep 29, 2018, 03:15 PM
Up! Up! And Away!
GottaZoom's Avatar
Thread OP
Originally Posted by Oldgazer
The first part of #4 (Work with OTX) ain't gonna happen. Jumper blew it big time and they are on their own...
I doubt problems cannot be fixed IF it makes sense for both teams. Kilrah offered them some good free advice about how to do their branch after the problems - after Jumper moved quickly to create their own repository - for me, that leads to bigger question marks about Jumper's coding resources than everything else.

Some have said or intimated Jumper never intended to meet the OTX terms, IIRC. Since Jumper has already worked with the deviation crowd, it's not hard to believe they thought they believed things would go similar - even if that proved to be naive.

At the moment, T12 problems seem to be a short list ...

- OTX learning for gobs of features (competitive radios share problem, are lots more money, or both)
- Multi-protocol module learning (Jumper already covers the Deviation alternative)
- Aesthetics & related functionality (button interface, cramped switches for pinchers, etc. - still lots to like here)
- QC (so far, only a few problem reports (RF shielding cover, haptic soldering, stick issues)

The long run will be interesting on this ... lots of people will not update their radio for years ... Jumper could just do a new branch off OTX after a major release (especially given the small number of Jumper-specific patches needed for a working branch). Heck, I've seen people in this hobby work on porting firmware that is orders of magnitude more complex than patching OTX for the screen and buttons.
Last edited by GottaZoom; Sep 29, 2018 at 10:06 PM.
Oct 02, 2018, 06:46 PM
early retired & loving it
Being new to the T12, I found it easy to lay the micro SD on the battery compartment ledge and slide it right into the slot.

I also found that not first using the optional SD card caused a loss of options when CREATE A NEW MODEL was selected.
Oct 05, 2018, 03:25 PM
Up! Up! And Away!
GottaZoom's Avatar
Thread OP
First firmware update of the JP4in1 Multi-Protocol Module

Hints/notes on updating to 1.2.1 (using WinX) while following the project developers' steps to update on the JP4in1 module that is part of the T12.

Instructions from the project developers. The list below follows the Index list at top of that link.
  1. Tools Required

    The instructions cover a number of independently designed and manufactured modules. As we go through the directions, we must carefully discern which instructions apply to features included in our module.

    As the 2nd bullet points out, the JP4in1 has a FTDI adapter built in, so we use CP2102 drivers instead of Maple drivers used for other STM modules. You will use your transmitter with installed module (make sure battery will not run low during process), and a mini-USB cable (Jumper supplied one) that you will later plug into the back of the module (not the TX).

  2. Preparation
    i. Install the Arduino IDE (software)

    This is software you install on your computer that lets you review, edit, and compile source code for the firmware that will be loaded into the module. Don't get creative, use the recommended version of the Arduino software.

    Also, donít forget to install/update Java app.

    ii. Download the Multiprotocol source and open the project

    Unless you know github very well, use the download link provide at this step. It's too bad Jumper used the old version instead of using the project master, because that made the shipped version at least a half year older than necessary. They were likely wanting to use what they assumed was a stable version. In reality, there have been continual updates and adds to this project - older protocols will be mostly stable, but sometimes newer receivers will may need updates, too.

    Create a directory on your hard drive for the MPM project files and extract the zip file contents into that directory. Note that when unzipping the archive it will create its own master directory with several sub-directories and many files.

    iii. Install the Multi 4-in-1 board, following the instructions (only STM is needed, but I also did the AVR as I have a couple of those modules)

    iv. Configure the Arduino IDE, following the instructions

    I used the following settings under Tools:
    - Board: Multi stm
    - Upload method: Serial inc bootloader (FTDI) [Note-did not use auto or USB]
    - Programmer: stm
    - Port: Installed CP2102 drivers and verified correct com port with Win

  3. Configure the firmware, following the instructions

    More detailed Instructions are found in the AVR or ATmega compiling section to read about optional features you can enable or disable. It may be interesting or even very important to familiarize yourself if you use the JP4in1 with a different TX.

    For my T12, I made a few changes to the default features as shown in the _config.H file:
    - Enabled Flash from TX (for future use)
    - Enabled DSM max throw (uses full normal OTX range, which is larger than Spektrum-see caution in source if using)
    - Disabled MultiStatus (used for ERSky9X)
    - Enabled MultiTelemetry (for OTX)

  4. Verify the firmware, following the instructions

  5. Preparing to upload the firmware

    By now you should have made sure you have the appropriate CP2102 driver installed for your PC/OS and know which com port is assigned by your computer. Verify this is correct in Tools.

    i. Select an upload method

  6. Upload via Serial inc. Bootloader (FTDI) - this step will not be necessary

  7. Flash from TX - this step is not necessary but could be used instead of the above with future updates

  8. Upload via USB - this step will not be necessary
    i. Install the Maple USB Drivers - not used with JP4in1

    ii Upload the firmware - Turn on TX (optional ĖI left mine off thinking of this as recommended for a serial programmer), connect the USB cable, verify com port again, make sure correct com port is selected in the Arduino software, then upload using Sketch -->Upload and wait for process to completely upload data to the module. When I turned on my TX I saw the new version on the status line in the attached screen.

  9. Precompiled Binaries - this may be used for future updates

  10. Troubleshooting - Hopefully you also won't need to do this this, but if so, use the RCG link in the instructions.
Oct 05, 2018, 07:48 PM
Up! Up! And Away!
GottaZoom's Avatar
Thread OP

Quick Reply
Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Jumper T12 Open Source 16ch Radio with JP4-in-1 Multi-protocol RF Module Hobby Porter Radios 680 Yesterday 06:22 PM
New Product Jumper T12 OpenTX 16CH Radio Transmitter with JP4-in-1 Multi-protocol RF Module for F scousethief 0 Jul 31, 2018 06:18 AM