{"product_id":"3x4-tastenfeld-matrix-eingabefeld","title":"3x4 matrix keypad - 5 V or 3,3 V","description":"\u003ch3\u003eProduct overview\u003c\/h3\u003e \u003cul\u003e \u003cli\u003e3*4-key keypad in a matrix arrangement for inputs and control commands\u003c\/li\u003e \u003cli\u003e12 individual keys in four columns and three rows\u003c\/li\u003e \u003cli\u003eConnection via eight signal lines, four for columns and four for rows\u003c\/li\u003e \u003cli\u003e5 V or 3.3 V power supply\u003c\/li\u003e \u003cli\u003eWith stable push buttons and Zener diodes for contact debouncing\u003c\/li\u003e \u003cli\u003eWireless design, connection cable fitted with a pin header\u003c\/li\u003e \u003c\/ul\u003e \u003ch3\u003eProduct description\u003c\/h3\u003e \u003cp\u003eThis 3*4 matrix keypad is an input interface for embedded systems and microcontrollers. The twelve keys can be read via eight signal lines: four lines control the columns, while four sensor lines detect the rows. This significantly reduces the number of connection pins required compared with twelve separate inputs.\u003c\/p\u003e \u003cp\u003eTo ensure reliable inputs, Zener diodes for contact debouncing are integrated. The signal voltages are 5 V or 3.3 V, depending on the controller board used. No power supply is required during input because the switches are passive; connection is made via a fitted pin header.\u003c\/p\u003e \u003cp\u003eFor test purposes, such keypads are used in combination with an LCD and scrolling text as feedback in combination locks. Robot control boxes use a keypad for mode management and setting limit values. Test setups for alarm systems or access controls require inputs without a mains connection, which this keypad provides. Machine protection using the two-person principle can also be prototyped with a dual keypad matrix.\u003c\/p\u003e \u003cp\u003eThe keypad requires a driver routine in the microcontroller or a suitable library. The power supply must be matched to the logic level of the board; if necessary, a level shifter must be installed between the keypad and the board. The keys themselves are unencapsulated; embedding them in epoxy resin or using a separate cover depends on the design.\u003c\/p\u003e \u003ch3\u003eSafety notice\u003c\/h3\u003e \u003cp\u003eThis keypad is intended exclusively for building prototypes and test and development setups. It is not intended for continuous use in safety circuits or household electrical circuits. Work on or immediately adjacent to electrical installations may only be carried out by a qualified electrician; if in doubt, consult a qualified electrician before commissioning.\u003c\/p\u003e \u003ch4\u003eScope of delivery\u003c\/h4\u003e \u003cul\u003e \u003cli\u003e1x 3x4 keypad \/ matrix - input keypad\u003c\/li\u003e \u003c\/ul\u003e","brand":"Funduino","offers":[{"title":"Default Title","offer_id":65997955039581,"sku":"F23106449","price":1.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1074\/5649\/5965\/files\/3x4-tastenfeld-matrix-eingabefeld-funduino-6497751.png?v=1791495595","url":"https:\/\/funduino.com\/en\/products\/3x4-keypad-matrix-input-panel","provider":"Funduino","version":"1.0","type":"link"}