DTMF module with dual audio outputs and MCU/dialing keyboard interface Key benefits Enables control by MCU or keyboard to generate standard 16 DTMF tones using two independent audio outputs. Supports simultaneous use of two 3.5 mm audio jacks, increasing flexibility for testing, routing, or direct dial tone output. Wide input voltage range simplifies integration with different power supplies (5 to 24 V DC). Simple MCU integration through a 7pin 2.54 mm header for easy signaling and power delivery. What it does Designed for dialing keyboard and MCU interfaces to generate the 16 dualtone multifrequency tones from audio outputs 1 and 2. Two 3.5 mm audio jacks allow parallel or independent audio connections for realtime tone output. Power and voltage Power port: DC power input via a 2.1 x 5.5 mm DC power jack. Wide voltage range: can be powered from 5 V to 24 V DC. Interfaces and connectors Audio ports: two 3.5 mm audio jacks for simultaneous use. MCU input port: 7 x 2.54 mm header with pins designated as 5V, GND, D3, D2, D1, D0, and STD. Technical specifications (summary) Working voltage: 5 to 24 V DC Working current: 6 to 8 mA Power port: 2.1 x 5.5 mm DC power jack Audio ports: two 3.5 mm audio jacks MCU interface: 7pin 2.54 mm header (5V, GND, D3, D2, D1, D0, STD) Function: generate 16 DTMF tones via Audio outputs 1 and 2 Applications: dialing keyboards, MCUcontrolled tone generation, dual audio output testing Use scenarios MCU controlled dialer: Connect the module to a microcontroller, issue D3..D0 codes to generate the corresponding DTMF digits for dialing or signaling, using Audio 1 and Audio 2 as tone sources. Telecommunication prototype: Use the dual 3.5 mm jacks to route tones to separate audio paths (e.g., one for a speaker, one for a test signal input) while keeping MCU control intact. Keyboard dialing tester: Interface a physical keypad or keyboard to trigger DTMF tones for testing voice or signaling paths in embedded telecommunication projects. Notes The module is intended for straightforward integration with MCU projects and keyboardbased dialing interfaces. All specifications are provided to assist in design and connection planning; no additional components or firmware details are implied beyond the described interface and capability.