Chris Borrill
Published © MIT

Stress Tester for Text UI Input Fields

The project is useful for stress testing text UI input fields. It generates characters at a controlled rate by emulating a keyboard.

BeginnerFull instructions provided4 hours141
Stress Tester for Text UI Input Fields

Things used in this project

Hardware components

Pro Micro - 5V/16MHz
SparkFun Pro Micro - 5V/16MHz
The Pro Micro uses an Atmel32U4 MCU which is capable of emulating a HID USB keyboard.
1.8 Inch TFT LCD Display Module
This display uses the ST7735 driver IC.
SPDT Sub-Miniature Toggle Switch
SPST PCB Mount Tactile Switch
USB-A to Micro-USB Cable
USB-A to Micro-USB Cable
Use this to connect the device to a USB socket on your PC.


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Key Typer Schematic

I built this device using Vero board, but it could easily be built on a breadboard.


Key Typer

The code for the device. The code in repository has the configuration files to allow it to be imported into the PlatformIO development environment, alternatively it may be edited in the Arduino IDE. The code uses three libraries; Bounce2 to software debounce the buttons and switch, the Arduino TFT library to drive the display and the Ticker library to control character generation rate.


This library is used by the project for software debouncing.

Arduino TFT

This library is used to drive the display.


The Ticker library to the control character generation rate.


Chris Borrill

Chris Borrill

2 projects • 4 followers