Computer-controlled Signal-randomized Translingual Neurostimulator

This project was commissioned by Diego in Canada in order to work with the MathAddict browser extension, whose GitHub repository may be found here, which itself builds off of MathAcademy. This system then controls the previously-built signal-randomized translingual neurostimulator using an Arduino Nano as a bridge between the computer and the translingual neurostimulator, enabling the neurostimulator to be USB-controlled.

Assembled TLNS boards

See ordering instructions and design files here:

https://www.instructables.com/Signal-randomized-Translingual-Neurostimulator-TLN/

USB-C to mini USB-B cable

https://www.amazon.com/Cable-Matters-Mini-Feet-Black/dp/B00UUBS0SS

Silicone-insulated wire, 20 gauge, 2 conductors

https://www.amazon.com/TUOFENG-Silicone-Electrical-Conductor-Parallel/dp/B0981P286D

Transistor, MPSA06

https://www.amazon.com/50PCS-MPSA06-NPN-Transistors-TO92/dp/B0DMT35ZLR

Resistors, 1.5k, 3.3k, and 10k, all 250mW

https://www.amazon.com/Molence-Resistor-Resistors-Assortment-Experiments/dp/B0C5N47J51

Capacitor, 10uF MLCC

https://www.amazon.com/Capacitance-Transparent-Electronic-Professionals-Enthusiasts/dp/B0GDS6L12N

Perfboard

https://www.amazon.com/Tulead-Perfboard-Prototyping-Circuit-Experiment/dp/B07V9LSJLZ

Arduino Nano clone with CH340 USB-to-TTL serial converter, best found through ebay -- item listings are named things like "MINI USB Nano V3.0 ATmega328P CH340G 5V 16M Micro-controller board for arduino"

https://www.ebay.com/itm/177244633950

Spar Urethane

https://www.truevalue.com/product/helmsman-11-5-oz-aerosol-high-gloss-spar-urethane/

Double-sided mounting tape

https://www.homedepot.com/p/Gorilla-1-in-x-1-67-yd-Black-Heavy-Duty-Mounting-Tape-6055002/308910063

Masking tape

https://www.homedepot.com/p/3M-ScotchBlue-1-88-In-x-60-Yds-Original-Multi-Surface-Painter-s-Tape-3-Rolls-2090-48EP3/305218415

Toothbrush

https://www.amazon.com/GuruNanda-DentalGuru-Gum-Massager-Toothbrush/dp/B0CHGQ4VHY

Distilled or deionized water

https://www.amazon.com/Distilled-Steam-Distilled-Drinking-Appliances-Medical/dp/B0FX43RGCT

Isopropanol (91%)

https://www.amazon.com/Isopropyl-Alcohol-Antiseptic-Topical-Solution/dp/B0FNK4FQLC

Rectangular food storage container

https://www.walmart.com/ip/Rubbermaid-Red-Plastic-Food-Storage-Container-3-Count/16664882

Lithium-Ion cells with built-in protection circuit (450mAh)

https://www.amazon.com/dp/B0CQ71ZS1X

Soldering iron (I'm using a MINIWARE TS100 -- since replaced by the TS101)

https://www.amazon.com/NovelLife-TS101-Soldering-Adjustable-Temperature/dp/B0BLNHB11B

Solder (SN100C alloy, 3% NC601 flux, 0.032" diameter)

https://www.amazon.com/FCT-SN100C-NC601-Clean-Solder/dp/B07RWRSYKK

AVR programmer (Atmel-ICE)

https://www.digikey.com/en/products/detail/microchip-technology/ATATMEL-ICE/4753379

Pin header (1x4, 2.54mm spacing)

https://www.digikey.com/en/products/detail/w%C3%BCrth-elektronik/61300411121/4846827

Personal computer (I'm using a CHUWI MiniBook X N100 -- since replaced by MiniBook X N150)

https://www.chuwi.com/product/items/chuwi-minibook-x-n100.html

Atmel Studio (version 7.0.2389)

https://sourceforge.net/projects/gcbasic/files/Support%20Files/ATMELCompilers/ATMEL7Studio_installer-7.0.2389-full.exe/download

The modified TLNS firmware is found on this project's GitHub repository,

https://github.com/quicksilv3rflash/computer-controlled-signal-randomized-translingual-neurostimulator

at /2026_04_02_TLNS_firmware/TLNS/main.c

Follow the TLNS firmware flashing instructions at

https://www.instructables.com/Signal-randomized-Translingual-Neurostimulator-TLN/

steps 9 through 14, but using the modified firmware linked above.

For the firmware flashing process, it is necessary to have a battery attached to the TLNS board (or an alternate means of powering it), but the battery is not required for operation of the final device configuration, as it draws USB power from the computer it is connected to.

This schematic shows how the TLNS device is connected to the Arduino Nano, the five additional discrete components required to facilitate communication, and the single component which must be removed from the TLNS board to allow for proper operation.

Solder the Arduino Nano to the perfboard, then add the communication bridge circuitry and output lead wires. The output wires from the MPSA06 transistor on the perfboard can now be connected to the TLNS device, across switch K1.

The CH340 integrated circuit on the Arduino Nano requires its own driver software to work properly with the computer. Sparkfun has created a detailed and useful guide to installing the required driver software at

https://learn.sparkfun.com/tutorials/how-to-install-ch340-drivers/all

There is also additional information -- and yet more potential driver installation files -- (though it appears partially out-of-date) at

https://sparks.gogo.co.nz/ch340.html

The Arduino Nano firmware is found on this project's GitHub repository,

https://github.com/quicksilv3rflash/computer-controlled-signal-randomized-translingual-neurostimulator

at /2026_05_11_arduino_bridge_firmware/2026_05_11_arduino_bridge_firmware.ino

The Arduino Nano bridge firmware was written and flashed using Arduino 2.3.6 on Linux Mint. It *should* work with any version of the Arduino IDE, but I am noting the precise version number and operating system used in the event that there are any compatibility issues of which I am unaware. Open the firmware in the Arduino IDE, select the correct port (Tools > Port > [should be the only available option, /dev/ttyUSB0 on my system]), board (Tools > Board > Arduino Nano), and bootloader variant (Tools > Processor > Atmega328P (Old Bootloader) ), then press Ctrl+R and then Ctrl+U.

Remove resistor R5 from the TLNS board. It is an imperial 0603 resistor (1608 metric), so it is easy to simultaneously reflow both of its solder joints and remove it from the board with the tip of the soldering iron.

Solder the 3.3kOhm resistor to the TLNS device as shown.

The remaining wires between the Arduino Nano and the TLNS device can now be soldered.

The test webpage is available at

https://www.neuroplustech.com/gedge_serial.html

if you wish to use it to test your hardware configuration. It is also in the project's GitHub repository,

https://github.com/quicksilv3rflash/computer-controlled-signal-randomized-translingual-neurostimulator

as gedge_serial.html if you would prefer a local copy.

The original design notes for this project may be of use to you, so they are included here.

The computer is connected to the Arduino Nano using a USB cable, and the Arduino's CH340 integrated circuit identifies itself to the computer as a serial COM port. Commands are then sent from the computer to the Arduino Nano at 115200 baud. These commands are in the format F#####I##D###### (e.g. F00200I17D000500) -- while designed with all integer values in mind, and assuming that the numeric portions would be fixed-length, the implementation in the code allows for more flexible input. The first character can be any letter, as the code simply checks if it is a non-zero value, but the second and third characters must be 'I' and 'D'. The length of the numbers is unlimited (within the Arduino Nano's 2kB of available memory). The first number, frequency, after 'F' and before 'I', is read as a string and then converted with a .toDouble() function -- a decimal point could be used to request a fractional value if desired. The second number, intensity, after 'I' and before 'D', is read as a string and then converted with a .toInt() function -- it must be an integer between 0 and 20, inclusive. The third number, duration (in milliseconds), after 'D', is read as a string and converted with a .toDouble() function -- a decimal point could be used to request a fractional value if desired.

The Arduino Nano bridge firmware listens to the COM port at 115200 baud for a command in the format described in the previous step, and then converts it to a pulse train and an analog value produced using pulse width modulation.

The Arduino Nano outputs a pulse-width modulated analog value and a pulse train -- the analog value defines the output pulse width of the translingual neurostimulator, ranging between 20 microseconds and 80 microseconds in 20 microsecond steps, and the pulse train defines the frequency with which the translingual neurostimulator produces these pulses -- one digitalWrite(2, HIGH); command in the Arduino corresponds to one pulse from the translingual neurostimulator.

As with the previous signal-randomized translingual neurostimulator design, the selection of the active electrode is randomized -- the connected computer controls the duration and frequency of output pulses, but not which electrode is being activated; which electrode on the grid is activated is reselected pseudorandomly within the TLNS device for each output pulse.