ISD1820 Voice Recording Module On-board Microphone

Reference : SEN18004

€4.90

Tax included

Voice Recorder/Player, with built-in microphone on board to record up to 10 seconds of voice and can play 20 seconds of audio.

Description

If you have any questions on this product please feel free to contact us.

*Disclaimer: The images are merely illustrative.

Specification

Operating Voltage	3~5Vdc
Color	Green, Black, Blue
Material	Plastic + iron + copper
Weight	19g
Dimensions	5.4 cm x 3.8 cm x 1.6 cm

Key Features of ISD1820 voice record and playback module

Record and playback up to 10 seconds of audio.
Pushbutton and MCU controllable
Edge or level activated playback
Built-in microphone
On-chip 8 ohm speaker driver
Duration and sample rate can be modified up to 20 seconds with resistor change
Auto power down mode
2.6 -5V operation

With the built-in microphone, you can record one message that is up to 10 seconds long. This can be extended up to 20 seconds with a resistor change. The message can be rerecorded up to 100,000 times and is non-volatile.

A small built-in audio amplifier can drive an 8 ohm speaker.

The main features of the module are shown below. Functions such as Record, PlayE and PlayL can be activated by pushing a button or input a logic HIGH on the header pin with the same name.

ISD1820 Voice Record and Playback Module - Connections

REC	RECORD – Pin is active HIGH to start recording and must remain high while the recording is in process. The red LED will light while recording. Once the pin goes LOW or it runs out of memory, an End-Of-Message (EOM) marker is automatically recorded. Pressing and holding down the pushbutton will also record a message. Release the button to stop the recording.
PLAYE	PLAY Edge – Pin is edge activated when it transitions to HIGH. The recording will play until the EOM is reached. The pin can be set LOW while message plays and it will not terminate the message. When EOM is reached the red LED will flash. Pressing the pushbutton will play the entire recorded message.
PLAYL	PLAY Level – Pin is active HIGH. When pin goes HIGH, the message will play until the pin is set back to LOW or the EOM is reached. Pressing the pushbutton will play the recorded message until the button is released or the EOM is reached.
REPEAT	REPEAT Switch – if moved to the right will play the recorded message continuously.
FT	FT Switch – if moved to the right will enable a Feed Thru mode of operation. In this mode of operation, any audio picked up by the mic will be sent directly out to the speaker
LED	LED Output – Normally HIGH, goes LOW when LED is lit
VCC	VCC can range from 2.6 to 5.5V. Only one VCC pin needs to be connected
GND	Ground should be common with the uC. Only one GND pin needs to be connected
NC	No Connect

The ISD1820 chip has a Resistor Controlled Oscillator input (ROSC) input. A resistor placed between the ROSC pin and ground sets the oscillator frequency and therefore sample rate and thus the maximum duration of the audio. As per the table below, a tradeoff can be made between using a shorter duration recording, but with a higher sample rate and bandwidth or the duration can be extended up to 20 seconds with a lower sample rate and bandwidth.

The module ships with a 100K resistor in location R4 that is connected to the ROSC pin on the ISD1820P chip. It is put into the circuit with the jumper at location P2. 100K is what sets the 10 second duration for the recording. R4 can be replaced, or the jumper can be removed and a different value can be jumpered from the header pin next to R4 to ground to change the recording characteristics per the table below.

ROSC	Duration	Sample Rate	Bandwidth
80K Ohm	8 Secs	8.0kHz	3.4kHz
100K Ohm	10 Secs	6.4kHz	2.6kHz
120K Ohm	12 Secs	5.3kHz	2.3kHz
160K Ohm	16 Secs	4.0kHz	1.7kHz
200K Ohm	20 Secs	3.2kHz	1.3kHz

It is also possible to record at one rate and play back at another. That will serve to speed up or slow down the playback which might be useful for creating sound effects. A pot can be wired in for this purpose.

The power output is sufficient to drive a small speaker or the output can be used to drive the input of an audio amplifier if a louder sound is desired.