Description:
  This kit adopts 20s voice recording circuit ISD1820P to achieve the save and restore of voice signal.
The chip adopts CMOS technique, the no power consumption information can be saved for 100 years.

Integrated circuit pin function is:
11 pin is power positive (VCC); 8, 14 pin connects power negative (GND);
1 pin is recording port (REC), high level valid; when the REC gets higher, the chip will start recording;
2 pin is edge trigger play (PLAYE); when this port has high level, the chip will start playing the voice;
after playing, it can release PLAYE;
13 pin is recording indication port (RECLED); when it is on recording state, this port is low, and it can drive LED;
4, 5 pin connects microphone input port (MIC);
6 pin connects auto gain control (AGC) port;
7, 9 pin connect loudspeaker output (SP+, SP-), and it can directly more than 8 ohm loudspeaker;
10 pin connects oscillation resistor (ROSC), connect oscillation resistor to GND.

Adjust oscillator resistor R4 connected with ROSC, it can stepless adjust the voice speed; the shorter of the recording voice, the better of the sound quality will be; otherwise, it will be worse.
Note: please do not adjust the resistor for too small, we recommend more than 100K ohm.

Parameter:
Operating Voltage: DC 3-5V

Component List:

NOTE:You can complete the installation by PCB silk screen and component listing.

Circuit Diagram:

Finished Product Picture:

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