Upgrade: TK Talkie v3 - Can You Hear Me Now?

Disclosure: I haven't been paid to promote any items in this post or been given any free samples for blogging.

A couple of months ago I built my TK Talkie v2, a device one of our 501st members in the Star Garrison devised using off-the-shelf Teensy Arduino hardware and some clever programming. He put his design and tutorials on his site at tktalkie.com.

Recently, TK Talkie came out with the v3 iteration of the device, which adds a Bluetooth Low Energy (BLE) module on top of the v2 design, and overhauled the file structure on the SD card, allowing integration with a phone app supported by iOS and Android. This allows the v3 device to use the following, powerful features:

• Saving, editing, deleting, and switching between multiple profiles, allowing for multiple setups or costume profiles on a single SD card an a single device
• Altering gain levels (Line In, LIne OUt, Mic, master volume, etc.) and equalizer settings on the fly (without the need of a computer as with the v2 device)
• Switching between the Line Out or Mic outputs on the fly (for example, if you need to switch to your wired mic because your wireless mic is dead or broken, or cross-talking with another wireless mic)
• Selecting a background loop, or turning it on or off on the fly

Previously many of these things could only be done with the TK Talkie connected to the computer while using the Arduino serial mode to make adjustments. Multiple profiles weren't possible without multiple SD cards. So this upgrade was a major improvement for ease of use and utility.

This video does a much better job of demonstrating it than I could put together.

With all these incentives, I decided to upgrade my v2 device to v3 using the online tutorial. I recommend reading the tutorial to better understand the build and my personal take on it.

To upgrade my current v2 to the v3 wasn't too hard, although there was a slight learning curve on the software side. Before that, though, I'll talk about my take on the v3 hardware.

Hardware

The key to the v3 build, really the only hardware difference from the v2 hardware, is the BLE module. TK Talkie's own design adds the BLE module to the Teensy board using 3.5mm jacks to make it removable. However, the BLE module shouldn't be disconnected while the device is powered on. Add this to the fact that the case I happen to use with my v2 device had plenty of room for the additional BLE module, and I decided to directly wire the BLE module to the Teensy without using a male/ female 3.5mm jack since I don't feel the need to disconnect it with all the space in my case anyhow.

One of my personal pitfalls with this design was the wiring and female pin connectors I used between teh Teesny board an dthe BLE module. Although they only require crimping, they should also be soldered to make a better, more dependable electrical connection. This was also exacerbated as I used small-gauge telephone conductors to have flexible wire between the BL and Teensy, since each piece is installed on a different half of the hinged case. Because I had a loose connection on one of my RX / TX conductors, the app would often connect, but not be able to pull up the profile or present the settings screen. I ended up removing the old ends and replacing them with modular female ends (with a touch of solder for good electrical contact) in a casing. Once this was fixed, I had zero issues using the app. This means that you can connect the BLE pretty close to the Teensy without any worry about Bluetooth connection.

Before and After pictures of fixing my BLE wiring

Software

With the hardware ready, it was time to load the software using the Arduino software and the Teeensy plugin. This was fairly straightforward, although I found that Windows didn't download the files correctly, typically saving tham as web pages with markup instead of as the .txt, .h, or .ino files required for the various directories. In fact, it was much easier for me to make my own files and structure with the proper names and extensions, and simply copy the text from the sketch sources and then paste them into those files.

Once the new files were uploaded, I was able to start personalizing things. One thing to keep in mind is that all files should be 8 or less characters in length, including profile names and sound names. This name size was done to make file access as fast as possible. Any filename longer than eight characters won't be read by the program. This affected a profile I created off-app and caused me to not be able to use it.

One thing to keep in mind is that you can change the background loop on the fly, but you must ensure that the effects_dir, loop_dir, and sounds_dir point to the correct directories, as there's currently no way to adjust these on the app (to be added in a future release). With the v3 file structure, these sounds are stored in their own directories, typically on the root of the SD card, so the sounds can be used by multiple profiles. All your sound files should be loaded to the SD card beforehand, including any background loops you may want to use, and referenced by the profile before loading the SD card into the TK Talkie (just edit your profiles with any basic text editor). Really, the only limits are your desired sound and the storage space on your SD card.

The App

The app is supported on iOS and Android. So far, the app works OK. Typically, I have to connect to my TK Talkie twice to communicate with the hardware, but this may because of my integration of the BLE close to the Teensy board and audio riser, whereas the reference design places the BLE module on its own dongle away from the other boards.

However, once it is connected (and with my wiring and pin connectors fixed), it's now terribly easy to make changes on the fly. For example:

• If I'm at a troop with mingling, I can set my device to use the profile with the background loop.
• Alternately, I can turn it off when it's not appropriate, or apply a saved profile without the background loop.
• If the loop is too loud, I can turn the volume on it down compared to my Line In/ Mic gain.
• I could make a new profile with less bitcrusher distortion for a cleaner sound.
• If there are too many troopers with wireless mics and I get cross-talk with another trooper, I can switch to the profile for the wired mic and use that instead (and adjust the loop as necessary).
• Turning off the mic volume but using voice activation to launch random Jawa sounds (and saving it as its own profile for your Jawa costume).

There are a lot of possibilities.

I can make these changes while wearing the armor too, which helps if I need to turn off a loop or swap out profiles after I've suited up. I have to fiddle with my chest plate far less with the app interface, unless I need to adjust my Pyle Pro's main volume.

Speaking of volume, one thing to keep in mind is the Line Out Volume with the current app, which actually works in reverse (to be fixed in the next update): that is, the lower the number is, the higher the volume. This threw me for a loop the first time I took the unit out in the field, as I had the volume set to 3 and was easily getting feedback. I've suggested that the interface be changed so that the volume is a negative number, like many home theater receivers (that measure output in -dB), going from -3 (highest) to -31 (lowest). With my Pyle Pro already amplifying, I set the TK Talkie to 31, the lowest setting, and adjust the main volume on the Pyle Pro.

Now that I have the basics down, I'm going to learn how to adjust the equalizer and bit crusher settings so I can dial them in some more. The fact that the app allows you to toy around with these advanced settings, without needing to go through a console connection, truly helps add to the utility of the app.

Final Thoughts

If I had to rate the system, I would give it a 4.5 / 5. The app is still slightly rough around the edges, but it's certainly a contender with other systems out there. The TK Talkie site has a comparison between itself and other systems, and although you may need to consider author bias, it's a decent comparison in features and considering your options.

Beyond my thoughts above, when you build or upgrade, definitely give yourself time to build and acclimate to the system. I rushed mine a bit to use it on an upcoming troop and it didn't go so well. Now that I have things fixed and a better understanding of the device, it's an invaluable part of my kit.

Above is the TK Talkie inside the upper right of my chest plate. The input is my wireless mic receiver to Line In on the TK Talkie. The output is Line Out to my Pylo Pro. A small USB battery under the Pyle Pro powers the TK Talkie for many hours. Everything's secured with H&L tape, which is your friend.

(One note is that I tried to feed the TK Talkie from the Pyle Pro power source by using a step-down transformer and a power switch, and although the TK Talkie got power from it, the power had far too much noise on it to be useful, even with a filter or two in place. I may reinvestigate this later, but for now a simple $10 USB battery is the best option (although just one more thing I have to worry about charging).)

If building your own TK Talkie is out of your comfort zone, you can now order them through the TK Talkie web site at http://store.tktalkie.com. Personally, I may build a few for my garrison to order when time allows, but now there's an alternative for those who might not be as comfortable with a soldering iron and development software as others.

That's it for the blog for now. Once my troops in May or finished, I may clean up the armor and finally submit for EIB status with FISD. Until next time, carry on troopers!