User Manual

VMA449
V. 01 – 12/02/2020 4 ©Velleman nv
Overview
1. MIC – Microphone input. The microphone input transfers its signals to the on-chip
amplifier.
2. REPEAT – Loop play the recorded sounds.
3. ISD1820 – Record/playback chip.
4. FT – Feed Through. This mode connects the speaker driver to the microphone amplifier.
5. Lead out header – VCC (3-5VDC)/LED/NC/FT/GND – VCC/REC/PLAYE/PLAYL/GND.
6. P2 – Default short connection Rosc to 100 kΩ resistor R4, which means the record duration
is 10 seconds.
7. PLAYL – Playback, level activated. When this input transits from LOW to High a playback
cycle is initiated.
8. PLAYE – Playback, edge-activated. When a HIGH going transition is detected the recorded
message will be played until the end of the recording.
9. REC – The REC input is an active HIGH record signal, the device records whenever REC is
high. REC takes precedence over either PLAYL or PLAYE.
10. Speaker outputs – The SP+ and SP- provide direct drive for an 8Ω loudspeaker, or can
also be used to connect to an amplifier (for example VMA408).
6. Operating Guide
1. Hold the REC button to record. The REC LED (D1) will light. Releasing the REC button will
stop the recording.
2. Select the playback mode:
o PLAYE: push one time and the full recording will be played.
o PLAYL: the recording plays as long as the button is pushed.
o REPEAT: move this sliding switch to the other position and the recording will continue
playing time after time.
o FT mode: move this switch to the other position, all the sound captured by the MIC will
go directly.