Description

ISD1820 Voice Recording module can be used for multi-segment recording. The mic is present on board and there is two pins (SP+ and SP-) present onboard to connect the speaker. Other than Speaker output pins there are 6 more pins on the

ISD1820 module i.e., Vcc, GND, FT, REC, PE and PL. Vcc and GND is used to power up the module by 3V-5V DC. FT pin is used to activate Feedthrough mode. In Feedthrough mode the input voice through the mic is played directly through the speaker. Whenever the REC pin receives an active high signal module starts recording the voice. PE is an Edge activated pin and it remains activated until the End of Message(EOM) or end of the memory space is reached. PL is a level-activated pin when the level changes from low to high it starts a playback cycle.

There are three buttons on the ISD1820 voice recording module which are REC, PLAYE and PLAYL. REC button is red in colour, unlike PLAYE and PLAYL which are black in colour. REC button as the name suggest is used to initiate the voice recording. The voice is recorded for the duration of time the REC button is kept hold (the maximum length of audio which can be recorded by the module is 20 seconds). When the REC button is released the module stops recording voice. By pressing PLAYE button whole speech can be played back. PLAYE button works on trigger mode. Whereas PLAYL button works on jog mode. Hence, the voice recording is played back for the duration of time PLAYL button is kept hold. As soon as the PLAYL button is released playback stops.

In the ISD1820 module flash memory is embedded on board used to save voice recordings. As this is a non-volatile memory, it can keep data stored even without power input. There is an internal audio amplifier in the module which is used to drive a speaker of up to 8 ohms 0.5W load.