- Directly controlled by 1.5V and 3.3V microcontroller serial ports. Whatever the serial output, the device reports it as spoken audio. For example, sending printf("Hello everyone") results in the device broadcasting "Hello everyone". It supports numbers, letters and Chinese characters. Practical, convenient and economical. - USB to TTL testing: can be connected directly to a USB to TTL module for quick testing. - Fixed baud rate: 9600, 8 data bits, no parity, 1 stop bit (9600,8,N,1). - Wiring and color code: red = 5V, green = RX, yellow = TX, black = GND. Use scenarios: -DIY microcontroller projects: add audible prompts or spoken feedback for interfaces, dashboards or educational kits. -Development testing: listen to serial outputs during hardware prototyping to verify data and flow without a display. -Small automation or smart devices: provide simple spoken status updates or alerts in compact setups.