Wireless MIDI Groups: 1-to-4 MIDI Thru & 4-to-1 MIDI Merge

WIDI Wireless MIDI

WIDI App for iOS

Great that you are here. It means you are really interested in WIDI. The wireless MIDI solution by CME. With WIDI you have access to the future of MIDI. This blog is intended for you if you are interested to be on top of the latest developments. It explains the basic terminology and it tries to explain the entire process step by step. 

How we work!

Before you go deep into the possibilities of WIDI technology, please ensure to understand the way we work at CME.

As a small innovator the CME team focusses entirely on the development of Bluetooth MIDI technology, our mission is to deliver Bluetooth MIDI to any MIDI enthusiast and make it available to any MIDI device.

Are we there yet? No! There are so many different forms of MIDI and MIDI devices, that this is our real challenge. Sure, we can deliver WIDI and develop an entire system that works perfectly with WIDI devices. That is our short term focus.

Our long term goal is to allow you to use Bluetooth MIDI anytime. It should not matter if you work with iOS, Android, Windows, Linux, ChromeOS, MacOS or other Bluetooth MIDI devices from Korg, Roland, ROLI or any other manufacturer. Also, if you work with traditional MIDI hardware and without computers, WIDI is also for you. 

The goal for 2021 is that with WIDI you can connect any MIDI instrument and enjoy the benefits of wireless MIDI.

Community-driven development

Of course, WIDI technology and Bluetooth MIDI is developed and approved by many clever engineers. That said, it is not about them. It is about you. What do you really need? What does work for you? And what do we need to do to make it user-friendly and easy to operate.

That is why we need you! You are in the center of our development process. You are the Community of MIDI Enthusiasts. That is why we launch concepts, prototypes and beta tests in our Facebook Community. With your feedback we can:

  • Fix bugs before going public
  • Create a better explanation and improve the experience for the entire community

We are blessed with a community that is so actively bursting our developer’s bubble. You provide us focus, honesty and allow the entire community to enjoy your contribution later down the line. 

Now we got our intentions sorted out, let’s move to today’s topic: the new iOS WIDI app.

Feel welcome to share any feedback with us. We’d like to know everything.

We are pretty confident that we can solve bugs, or deliver a better explanation through our videos and this blog. Before you start creating wireless groups via BLE MIDI, it is important to explain a couple things about our technology. 

Read the remaining part of this blog with care!


iOS WIDI App version vs WIDI firmware version

First of all it is important to distinguish two different types of updates. You have an updated iOS app that currently runs 1.2.XX. You need to update that first. Next, to fully access the latest features, you need to upgrade your WIDI devices’ firmware to version v0098 or higher.

Upgrade firmware one-by-one!

It is important to understand that WIDI devices upon themselves are designed to be as easy in use as possible. That is why WIDI devices pair automatically. They automatically switch between the central role and the peripheral role.

Generally speaking, it does not matter if your device is the central or peripheral. As both roles allow bi-directional (duplex) communication.

The central and peripheral role become important when updating firmware and setting up groups with multiple WIID devices. You can update your firmware with the WIDI app. In this case, you need to understand that the WIDI App (thus your mobile device) becomes the central device to push settings towards the peripheral (your WIDI device).

If you update one single WIDI device, simply boot it and pair it with your WIDI App. Next you can update to firmware v0098 or higher.

Please note, when working with multiple WIDI devices, you can only update one-by-one. A common mistake that is made, is to boot multiple WIDI devices at the same time. This will make the WIDI devices pair automatically to each other. And when paired, the WIDI App cannot locate the device anymore as they are already occupied.

So, when updating firmware, power your WIDI device up one-by-one and update the firmware one at the time!

If you run into complexities, try these options first:

  1. Ensure you are using WIDI App 1.2.XX
  2. Ensure your iOS device is running iOS 14.3
  3. Ensure your iOS device and WIDI Master are the only BLE MIDI devices that are powered. This to avoid automatic pairing with other BLE MIDI devices. This is only for Bluetooth MIDI devices. Not all your Bluetooth devices.
  4. Ensure you empty cache on iOS by toggling general Bluetooth settings off and on.
  5. Enable Bluetooth in general settings, but do not pair it already there. Only pair it in the WIDI app.
  6. Next, pair iOS and WIDI Master in the WIDI App. Is there a connection established? Do you see blue leds on WIDI Master? Do you see the WIDI Master showing in WIDI App?
  7. Now you can update the firmware. If not, please reach out to us via the support form. 

How does this work?

So, if you want to upgrade the firmware for your specific WIDI device, you need to operate this step by step. First you turn on one WIDI device. Next you pair that with your WIDI app. Now you can control the settings of your WIDI device (peripheral) from the iOS WIDI app (central).

When you have upgraded the firmware for the first, switch it off. Only after this, you can power up the second. You repeat this process before you power up the 3rd WIDI device.

It may seem a bit complex at first, but the automatic pairing and role automation is designed so that any enthusiast, no matter the level of experience, can work with WIDI technology. When creating wireless MIDI groups, you enter a more advanced world of wireless MIDI that requests knowledge and dedication to make your MIDI setup future-proof.

So, there we have step 1! 

First update all your WIDI devices with (iOS) app v 1.2.XX to firmware v0098 or higher. And do this by manually booting each device one-by-one and allow it to pair WIDI to iOS app to push the new firmware into your WIDI device.

What can you do with WIDI firmware v0098 (or higher) and WIDI iOS App 1.2.XX?

  • Group connectivity
    * Set up to 4 peripherals and 1 central with duplex transmission
    * Create 1 group of up to 5 WIDI devices in a Bluetooth MIDI network.
  • Renaming of WIDI devices
  • Advanced settings
    TX power: Save power consumption by selecting lower dB level (note: the connection range will be reduced accordingly).
    BLE role: Force to Auto, Peripheral or Central.
    Set personal preferences: optimise for low latency performance or low jitter performance
  • Reset default connections
  • Factory reset
  • Timestamp support
  • Long SysEx support

So – Step 2 – let’s try this explanation video first! Let us know if this makes it clear to you!


Read this transcript that describes the video content step by step!

  • Step 0: Ensure you use iOS WIDI App (version 1.2.11 or higher).
  • Step 1: Please upgrade your WIDI devices to the latest firmware (first fw version for group connection is v0098). If you have multiple units, remember to not power up multiple WIDI devices at once. As they will pair 1-to-1 automatically, and that will make it impossible for the iOS app to pair with your WIDI devices. 
  • Step 2: Set your WIDI to the peripheral role and give it a new name.
    * Select “Force peripheral” in BLE role section, the setting will be saved into your WIDI automatically.
    * Click the device name in Status section to rename your device. You will need to reboot your WIDI device to see the changes.
  • Step 3: Repeat above steps to set all WIDIs that you want to add in a group.
  • Step 4: After you set all WIDI devices in peripheral role, please switch them on.
  • Step 5: Click “Groups” menu and click “Add a new group”.
  • Step 6: Enter your name for the group.
  • Step 7: Drag & drop your WIDI devices to the central and peripheral places.
  • Step 8: Click “Download group”, the group setting will be saved in all WIDI devices. Next, all units will be rebooted automatically.
  • Step 9: Wait for few seconds, all WIDI devices that you set as the group will connect to each other.
  • Step 10: All settings will be remembered even when you switch your WIDI devices off. Next time when you switch them on again, they will connect to each other in the same group.|

    * Note: If you want to forget the group connection setting, please go to each WIDI Status page and click “Reset default connections”.

How many WIDI devices can I add to this group?

Please note, when working with a Bluetooth MIDI group, there can only be one (1) central. Besides this, there can currently be up to four (4) peripherals. When you switch on multiple WIDI devices at the same time, they will automatically connect to each other. One WIDI device will take that central role (turquoise led indicator) following your manual settings through the WIDI App when creating the group.

Please note, when you are setting up this group, your iOS device has to be the central. Therefore, first you need to force all your WIDI device to become the peripheral mode and not connect with others. Otherwise, due to automatic pairing and role automation, they cannot be found by the (iOS) WIDI app. As the WIDI app has to be the central to allow you to make the settings for group connectivity first.

  • First set all your WIDI devices to “force peripheral”,
  • Next, create your group and select one central,
  • Finalise this process by pushing the manual settings to load by default for all group members.

1-to-4 MIDI Thru // 4-to-1 MIDI Merge

Can I only add WIDI devices to the group?

For this moment, yes! As mentioned before our mission is to deliver Bluetooth MIDI that can integrate and connect with any other Bluetooth MIDI device. This is of course great, and it is what WIDI technology distinguishes from any other Bluetooth MIDI adapter manufacturer. That said, this mission comes with challenges.

For instance, Apple’s iOS and MacOS do not provide fixed original Bluetooth addresses to connect with your WIDI devices. For security reasons, Apple changes the Bluetooth address of its own devices and others every 15 minutes. That is why, at this moment, it is not possible to add other BLE MIDI devices in your group connectivity setup. 

We are aware of this and our clever developers will find a solution for this to allow any BLE MIDI device to be part of the wireless Bluetooth MIDI network. 

MIDI Thru vs MIDI Merge

When creating a group, you can add up to 5 devices. The group always will have 1 central WIDI device.

Besides this you can add up to 4 peripherals. As communication is duplex, like bi-directional, you actually create a MIDI Thru or MIDI Merge functionality. In short. this means that with this firmware (v0098 and up), you can bypass MIDI interfaces, MIDI merge boxes and MIDI Thru boxes. You now can create the following wirelessly:

  1. 1-to-4 MIDI Thru  – Group of max. 5 WIDI devices
  2. 4-to-1 MIDI Merge – Group of max. 5 WIDI devices

Can I create multiple groups and run them simultaneously?

Yes you can. You can create groups starting from 2 WIDI devices. You can  have multiple WIDI groups to build a complete wireless system with automatic setup. This means, you create the group step-by-step first via the WIDI App. And when it is saved, it connects instantly upon reboot.

This way, you can fully automate your advanced MIDI settings by setting your different connections by default via multiple groups.

One WIDI device has a light blue colour?

That is correct. The WIDI devices are designed to indicate their role and activity through different LED colours. The light blue (turquoise) indicates that, that device is operating as a central. The dark blue indicates it are peripherals. Check out this video for a complete understanding.https://www.youtube.com/embed/n5R_-5wO7Lk?rel=0&modestbranding=1&controls=1&showinfo=1&fs=1&wmode=transparent

My WIDI devices light up Blue but my MIDI devices do not respond?

In a few cases this is caused by a phenomenon called MIDI loop. Please try to switch off MIDI thru functions in your MIDI devices or DAW. Or deselect WIDI as MIDI Input device in your DAW. When working with MIDI hardware, try to locate the MIDI Thru switch in your MIDI instrument and switch it off.

My WIDI devices disappear (or are only shortly visible) from the Bluetooth general settings on MacOS or iOS?

Once a WIDI has been connected to another, you will not be able to see it from other BLE MIDI device (such as your iOS App). That is why when you want to connect WIDI to iOS app, you must set them one by one. Also you need to force them to the peripheral role prior to setting the group in the WIDI App.

If you do not do this the WIDI device is set to auto role by default. It will try to connect to another WIDI automatically. If this is the case, you have no way to see it from your iOS app because it was occupied by other connection.

When you set a group, that means the central is in “Auto role” with predefined peripheral address. It will only connect to predefined WIDI peripherals. Or switch itself into peripheral mode to connect to another central.

Can you explain one more time central and peripheral in relation to group connections?

When setting a group you set one single WIDI device as a central device. The remaining (max four) WIDI devices you will set as peripherals. This way, the peripherals will not try to – automatically – find other BLE MIDI devices. They simply wait for the central to match the default group setting you saved.

Therewith, after you set the first group, they will only connect to each other automatically.

Once they connect, you are not able to see them from the WIDI App, because all of them are already occupied and connected with your groups central device.

Can I reset a group?

If you want to reset the group, you need to switch on the central first. And only the central. Not the peripherals, as they will pair automatically with the central. And not allow you to pair that central with the WIDI App.

The WIDI App has to become your temporary central to push settings into the WIDI devices. Therefore, you need to start with the central first. As it is set as “auto role”, you can pair this device with the WIDI app.

Next you force it into peripheral mode by using the app (or there is a shortcut, you can hold the button of the central for 3 seconds while the power is on). This way, it will not connect to any other BLE MIDI device but wait for new connection. Now you can switch on other peripherals together, then use the iOS app to set new central to build a new group.

When will this be available for Android?

As soon as we’ve finished optimising the iOS app, we will invest all the time we have to develop the Android solution. This can still take a few months before it is ready. When we launched WIDI Master in July 2020, we pushed Android first. That is why we now in 2021 push iOS first. That seemed most fair to us.

We are changing to a common development tool for both iOS and Android App. This will prevent that we need to develop them separately as currently is the case. Please give us more time. After this changing, we will be able to release them simultaneously.

Also, remember, we are a small team with only two products on the market today. It takes a bit more time compared to our big friends.

I have trouble with disconnection between my WIDI device and iOS?

The first thing you need to check is if your device is sending MIDI clock. If that is the case, turn that off in your MIDI device. The current version of the app does not filter MIDI clock and that causes issues. We are aware of this and will solve it in the next version. If you still experience troubles, check your iOS version and move to the section below.

I have trouble with connections on iOS 14.2?

Please note that it is widely reported that iOS 14.2 is causing issues with everything related to Bluetooth. Including Bluetooth MIDI. This has nothing to do with WIDI. It is recommended to move to iOS 14.3 (or higher) and follow the instructions below.

When you run 14.X and have troubles with your particular music apps, it is recommended to reach out to your music app developer and/or forums to locate specific information that applies to your use case.

How do I reset my Bluetooth connection on iOS?

Please note that Bluetooth cache causes many issues when working with advanced WIDI technology. Just like WIDI is designed with automatic pairing and auto role switching, iOS is developed with Bluetooth cache to improve the consumer experience. 

When using Bluetooth MIDI, you actually become a prosumer. You are digging much deeper into Bluetooth technology compared to a regular Apple AirPod music experience. If you experience issues with your WIDI device on iOS, always try to reset your Bluetooth cache by toggling the Bluetooth off switch in the iOS preference settings. Just follow the instruction below.

Just follow these easy steps to simply reset Bluetooth on iOS and forget your Bluetooth accessory.
1. Launch Settings and head over to Bluetooth.
2. On the right side of the Bluetooth device name, tap on the “i” icon.
3. Now tap on “Forget This Device” button and confirm.

Turn off Bluetooth and Restart
4. Restart the Bluetooth on iOS by toggling the Bluetooth off/on switch in settings

Pair Again
5. Now pair again with WIDI

How do I properly setup iOS and WIDI?

Check out this video and use midimittr as a bridge app on iOS. It works in the background and does not interfere with other music apps you like to use.https://www.youtube.com/embed/5SWkeu2IyBg?rel=0&modestbranding=1&controls=1&showinfo=1&fs=1&wmode=transparent

I can already connect multiple devices via iOS and MacOS?

Yes you can connect multiple WIDIs with MacOS or iOS as a central as well. It can take up to 7 peripherals. Please note this is based on MacOS/iOS Bluetooth MIDI and can have a negative effect on latency performance. To do this you need to force all WIDI devices to the peripheral role or switch them on one by one. This way they can connect to the central and not automatically pair to each other.

Please note that this is not the same as the WIDI Group connectivity we are discussing and testing here. 

I’d like to report feedback!

Simply reach out to us through the support form. We are happy to work with you and always try to reply within 24 hours!

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