Back to the Getting Started Guide
The minimum viable setup is the bare minimum you need to even run the Syntherrupter firmware. It won't be ready to use yet but it will allow you to flash firmwares and get to know the user interface.
You'll always need a Syntherrupter firmware, preferrably the latest release. You find all releases here: https://github.com/MMMZZZZ/Syntherrupter/releases/
Read the release notes and download the attached ZIP file. It includes all the firmware binaries you'll need.
Details about how to flash those firmwares are described on a separate page: Firmware Flashing.
The heart of Syntherrupter is the TM4C1294XL LaunchPad from TI. The Microcontroller is part of their Tiva family (Cortex M4F microcontrollers), hence I'll call it Tiva in the following.
This dev board can be bought directly from Texas Instruments for 20$, or from distributors like Mouser.
Everything else will connect to this board. How? Where? What pins? Beside the information given here you should check the Wiring and Schematics folder which includes schematics and pinouts.
Syntherrupter was originally designed as touch screen device. However, if you don't want a graphical user interface you can easily control it via command line, too. In that case you really only need the Tiva board.
Syntherrupters UI is designed for a special touch display called "Nextion". They have their own microcontroller that runs the whole UI which makes development a lot easier. Assembly gets easier, too. No 40 pin flat-flex cable, only 5V supply and two data pins.
There are multiple display versions that can do the job. If you don't care and simply want to go with the recommended display from the recommended shop, click here and you're good.
Btw. since they are resistive touch screens, they aren't affected by EMI like the capacitive screen of your smartpone.
You don't need a standalone interrupter? Well, you can run the user interface on the PC, too. In that case you don't need a display at all (see below).
Nextions ease of use comes at a cost. Literally. These displays are rather expensive, starting at 64$ for the 5" version. Starting? Yes, there are actually 6 displays that are suitable for Syntherrupter:
NX8048T050_011R: Nextion 5" Basic series (Official shop: 65$)NX8048T070_011R: Nextion 7" Basic series (Official shop: 75$)NX8048K050_011R: Nextion 5" Enhanced series (Official shop: 72$)NX8048K070_011R: Nextion 7" Enhanced series (Official shop: 83$)NX8048P050_011R: Nextion 5" Intelligent series (Official shop: 64$)NX8048P070_011R: Nextion 7" Intelligent series (Official shop: 73$)
I recommend buying them from the official shop, but some of them are available from Mouser, Digikey, etc.
The R at the end is important! It indicates that its the version with resistive touch. There are also versions with capacitive touch, marked by a C and versions with no touch, marked with an N.
The three different series differ by quite some features but the only important difference for Syntherrupter is the processor speed. The Basic series runs at 48MHz, the Enhanced one at 108MHz and the Intelligent one at 200MHz. The latter one used to be more expensive than the other two (which somewhat makes sense) but right now it's not. So by all means, go for it. Makes the UI run much smoother than a basic series screen.
Plot twist: Nextion is actually not much more than a rebranding. The displays originally come from the chinese manufacturer TJC. Buying directly from those is 30-50% cheaper but they only sell within China so you have to use an import service like Superbuy. Still cheaper than buying a Nextion but also slower.
The TJC displays have almost the same model numbers and start with TJC instead of NX:
TJC8048T050_011R: TJC 5" T0 (Basic) seriesTJC8048T070_011R: TJC 7" T0 (Basic) seriesTJC8048K050_011R: TJC 5" K0 (Enhanced) seriesTJC8048K070_011R: TJC 7" K0 (Enhanced) seriesTJC8048X350_011R: TJC 5" X3 (Intelligent) series (slower flash)TJC8048X370_011R: TJC 7" X3 (Intelligent) series (slower flash)TJC8048X550_011R: TJC 5" X5 (Intelligent) seriesTJC8048X570_011R: TJC 7" X5 (Intelligent) series
To keep things simple I won't write "Nextion or TJC display" every time but simply call it "Nextion".
Warning! You can find the displays on ebay, too. However, in most cases you'll get a TJC display even though it says Nextion. For Syntherrupter this doesn't make a difference but if you ever want to do something with them on your own, be careful about this or you will run into problems.
The user interface can be run on a Windows PC. Unlike the command line interface the GUI requires an additional Serial to USB converter that connects to the same Pins as the Nextion display would (see below).
- Download, install and open the Nextion Editor.
- For firmwares up to v4.1.3 you need Nextion Editor v1.61.1 (Download as ZIP (portable) or Installer).
- For firmware versions 4.1.4 to 4.2.0-beta.5 you need Nextion Editor v1.62.1 which is not available for download anymore; Nextion wants to force people to use v1.63.x and newer. For the record, here are the broken links: ZIP (portable), Installer. Workaround: download the "Source Code" zip file attached to the release and open the .HMI file that can be found in the extraced zip content under
Syntherrupter_Nextion/Syntherrupter_Nextion.HMI. You can use pretty much any Nextion editor version but I'd recommend v1.63.3 (see next point). Once you opened the file in the editor, contine with the steps below. - For firmware versions 4.2.0-beta.6 and newer you need Nextion editor v1.63.3 (Download as ZIP (portable) or Installer).
- Click "Debug" on the top right. A file dialog opens. Select the Syntherrupter_Nextion_NX8048T050.tft file from the release zip file.
- A new window opens. At the bottom left select "User MCU Input" and then the COM port of the Serial to USB converter. Baud rate is 115200baud/s.
- You may need to reset the Tiva.
- You should see the Syntherrupter logo. Since its a touch screen firmware, you can only use your mouse; no keyboard.
Tiva pins:
- PA4 connects to Nextions RX pin (yellow)
- PA5 connects to Nextions TX pin (blue)
Both Tiva pins are 3.3V logic pins, capable of 2mA current. They are 5V tolerant.
The Nextion display requires regulated 5V at 1A. If possible you should not power the display through the Tiva LaunchPad. The PWM modulated backlight causes a rather strong ripple that may cause issues. If you're facing weird behavior you can try adding a low ESR capacitor in the ballpark of 220uF across the DC input jack on the Nextion screen itself. This greatly reduces the PWM ripple.