KIT188 40-Second Voice Recorder & Playback Module Kit with ISD1740 IC

The KIT188 40-Second Voice Recorder and Playback Module Kit is a versatile DIY audio project built around the advanced ISD1740 voice recording IC, providing high-quality, non-volatile voice and audio recording for a wide range of electronic applications. Designed for students, hobbyists, product developers, and embedded system designers, this module offers an easy-to-build solution for adding voice prompts, recorded messages, alarms, and audio playback to custom electronic projects.

Replacing the earlier KIT146 based on the obsolete ISD2540, the KIT188 incorporates the modern ISD1740 integrated circuit, delivering improved functionality while maintaining approximately 40 seconds of recording time at the default 8 kHz sampling frequency. The ISD1700 family supports adjustable sampling frequencies between 4 kHz and 12 kHz, allowing designers to optimise the balance between recording duration and audio quality for their specific application.

Unlike compressed digital voice recorders, the ISD1740 stores audio directly in onboard Flash memory without digital compression. This preserves natural voice and music quality while ensuring recordings remain safely stored even when power is removed. The non-volatile memory eliminates the need for backup batteries or external storage devices.

The module supports both standalone operation and SPI (Serial Peripheral Interface) control, making it suitable for simple push-button voice playback systems as well as sophisticated microcontroller-based designs. In standalone mode, the module can operate independently, while SPI mode allows complete control of recording and playback functions from compatible embedded systems.

Audio can be recorded using the onboard electret microphone or through the analogue line-level input, providing flexibility for recording voice, music, announcements, or externally generated audio. Playback is available directly through an 8 speaker driven by the onboard amplifier or via the analogue auxiliary output for connection to external amplifiers or audio systems.

An onboard LED provides clear visual feedback during operation, remaining illuminated while recording and flashing during playback, making the module easy to monitor during use.

As a DIY electronic kit, the KIT188 offers valuable practical experience in soldering, PCB assembly, digital audio electronics, embedded systems, and audio signal processing while producing a highly practical voice recording module suitable for numerous commercial, educational, and hobby applications.

Features

• Based on the ISD1740 voice recording and playback IC
• Records up to 40 seconds of high-quality audio
• Non-volatile Flash memory retains recordings without power
• Audio stored without digital compression for improved sound quality
• Adjustable sampling frequency from 4 kHz to 12 kHz
• Operates in standalone or SPI-controlled modes
• Built-in electret microphone for direct voice recording
• Analogue line input for external audio sources
• Direct speaker output for 8 loudspeakers
• Auxiliary analogue output for external amplifiers
• Onboard LED indicates recording and playback status
• Excellent for voice prompts, announcements, alarms, and embedded audio projects
• DIY electronic kit ideal for education and product development

Specifications

• Product Code: KIT188
• Device Type: Voice Recorder and Playback Module Kit
• Recording IC: ISD1740
• Operating Voltage: 8-24 VDC
• Recording Time: 40 seconds (at default sampling rate)
• Default Sampling Frequency: 8 kHz
• Adjustable Sampling Frequency: 4-12 kHz (via external resistor)
• Memory Type: On-chip non-volatile Flash memory
• Audio Storage: Direct analogue recording (no digital compression)
• Operating Modes: Standalone mode and SPI interface mode
• Audio Input: Onboard electret microphone and analogue line input
• Audio Outputs: Direct 8 speaker output and analogue auxiliary output
• Status Indicator: Onboard LED (steady during recording, flashing during playback)
• Construction: DIY electronic kit
• PCB Type: Through-hole component assembly
• Typical Applications: Voice announcements, alarm systems, talking projects, educational electronics, embedded systems, interactive displays, access control, automation equipment, toys, information kiosks, and custom audio playback systems.

What's in the box
1 x KIT188 40-Second Voice Recorder & Playback Module Kit with ISD1740 IC