Source: https://mokxi.com/parts/ttp223 Updated: 2026-11-10 Part # Touch sensor, TTP223 A finger on the pad drives SIG high within 60 ms. No pull-up, no bounce. See every part - 3 pins - 2 settings - In 1 project - In 1 lesson Drawn live by the editor's own code, at the size you see it. At a glance ## The Touch sensor, TTP223 in brief What it is, and every setting the properties panel gives it. The TTP223 module is the small red square with a round pad printed on it, a capacitive touch sensor: a finger adds a few picofarads to the pad, and the chip drives SIG in response. It has three pins, SIG, VCC and GND, and runs from 2.0 to 5.5 volts, so it powers from an Arduino Uno’s 5 volts or straight from an ESP32’s 3.3 volts, keeping SIG safe for its pins. SIG is a push-pull output, so it needs no pull-up and does not bounce. Mokxi follows the Tontek datasheet: a touch takes the full 60 milliseconds to reach SIG and so does a release, so a shorter tap is never seen, and SIG sits at its power-on state for half a second while the chip calibrates. A finger already on the pad when that time ends becomes part of the pad, which is the classic fault of a module that ignores its first touch. The toggle and activelow properties are the B and A solder jumpers on the back, for toggle or active-low output. Sensitivity, slow recalibration and water on the pad are not modeled. Family Inputs Pins 3 toggle false activelow false A circuit built around it, running and explained: the Touch sensor simulator. Pins ## 3 pins Named as the editor names them, so a wire lands where you expect it. Pin Role What it does SIG Output A push-pull output, HIGH while touched as shipped. VCC Input or output Supply, 2.0 V to 5.5 V. GND Input or output Ground. How to use it ## How to use the TTP223 touch sensor with an Arduino SIG to a digital pin, VCC to a supply and GND to GND. SIG is a real output, so set the pin to plain INPUT, not INPUT_PULLUP, and it reads HIGH while a finger is on the pad. The climate display here powers the module from the Uno’s 3V3 pin, and its 3.3 V high still reads as HIGH on the 5 V Uno. To make the pad a switch, act on the rising edge, the moment SIG goes from LOW to HIGH, not on the level; holding a finger there then flips the setting once. Keep fingers off the pad for the first half second after power-up: the chip is calibrating then, and a finger still on the pad when it finishes becomes part of the pad until it lifts off. Part pin Board pin SIG Pin 2 VCC 3V3 GND GND On an ESP32 power it from 3.3 V and read SIG on any GPIO; the ESP32-C3 desk robot reads its pad on GPIO 3. Hold the button This is the simulator itself, running here. Click anything to open it in the editor. Open this project in the editor Read the full tutorial Flipping on each touch, from the climate display How it is modeled ## What is true about the Touch sensor, TTP223, here In its help article’s own words: what the simulation gets right, and where it stops. ### Modeled From the Tontek TTP223 datasheet: Response time. Up to 60 ms in fast mode, which is the only mode the six-pin chip on these modules has. A touch takes 60 ms to reach SIG, and so does a release. A tap shorter than that is never seen. Power-on calibration. For about half a second after power comes up the chip is measuring the pad and ignores it. A finger already on the pad when that time ends becomes part of the pad: it has to come off and go back on before it counts. The output. A real push-pull output: 8 mA sink and 4 mA source at 3 V, so it drives a pin or an LED with no pull-up. No time limit. The module's chip has its maximum-on-time timeout disabled, so SIG stays high for as long as the finger stays. ### Not modeled Sensitivity (the pad feels a finger or it does not), the slow recalibration while untouched, and water on the pad. From TTP223 touch sensor, in full. Projects ## See the Touch sensor, TTP223 in a project One built-in project uses it. It opens in the editor, already wired. Lessons ## Where it turns up in a lesson One lesson places it in its own circuit. ### Learn articles 1 lesson - Arduino Touch Sensor (TTP223): Wiring and Code Boards ## The boards it is shown on This board has a built-in project with the Touch sensor, TTP223 in it. - Arduino Uno R3 More parts ## The rest of the bench Every one of these is drawn and simulated the same way. Full-size breadboard A real 0.1 inch grid with the rails and the center channel, 63 columns wide. Jumper wires Drag from any pin or hole to any other. Corners snap, and you can drag them. Power A supply rail at the voltage you choose. Ground The other end of every circuit. LED Lights when current flows. Five colors, and the brightness is what your eye would see. Filament lamp A tungsten bulb in a holder: an inrush when it is switched on cold, tens of milliseconds to warm up, and dim on half its voltage. Resistor Any value you like, with the color bands drawn to match. ESP32-C3-DevKitM-1 A RISC-V board that runs your firmware at 160 MHz on the real memory map. Pushbutton A 12 mm tactile switch. Hold it while the simulation runs. Raspberry Pi Pico The RP2040 board on our own Cortex-M0+ core. Pick a program and press Run. Raspberry Pi Pico W Raspberry Pi Pico W (RP2040). The same board and the same pinout as a Pico, with the CYW43439 on it. The WiFi is simulated (no radio; real internet through the Cloud panel’s switch), and the on-board LED, which hangs off that chip rather than off GP25, is driven through the same path. Everything else is the Pico. Raspberry Pi 4 Model B Raspberry Pi 4 Model B: the 40-pin header, driven by main.py with RPi.GPIO or gpiozero. See every part ## Wire up the Touch sensor, TTP223 Open the editor and push it into the breadboard. It is free, and it runs on your own machine. Start building free Open the editor