Research
Features using the ISD1932
- Direct mode can save up to 8 different messages
- Has a microphone to record messages
- The R_osc of 53.3 kΩ will achieve a sampling rate of 12 kHz
- Works with 8Ω speakers
- Can use this for both the fount and the cup
- Many examples to reference from
- Max current at 30 mA
- Operates at 2.4 to 5.5V
- Price per unit: $6.32 from digikey.com
Circuit Diagram
Table representing message count
Table for R_osc and amount of allowed time
The duration's the messages can be at 12 kHz sampling rate in seconds
Therefore with a sampling rate at 12 kHz we get 2 messages that can be 10.65 seconds for the fount.
Block Diagram
Alternatives
The WTV020-SD
- This would be a backup driver if the ISD1932 is not a good option
- You can use an SD card as memory and it can hold an SD card that has up to 1GB of memory
- Sampling rate from 6 kHz to 36 kHz
- Voltage rating of 2.7-3.5 volts
- $19.95 from sparkfun.com
Speakers for the fount
Speaker COM-10722
Description
- Thin Speaker that could be used for the fount
- Impedance of 8 Ω so it will work with the driver as well
- Frequency range from 0 – 20 kHz
- Sound level is at 96 dB so it is much louder than the small speaker
- Maximum power is .4W which is a lot less than the speaker for the cup
- Price: $0.95 from sparkfun.com
Backup Speaker
- Bigger speaker that could be used for the fount
- Impedance is 8 Ω so it will work with the driver
- The maximum power is .5 W which is still relatively low
- Price $1.95 from sparkfun.com
Pseudocode for the Fount
The founts audio will be triggered when the cup is taken away from the fount and when the pouring action is complete
Void playAudio(int audiotype)
{
//Turn of all sound
M1 = 0;
M2 = 0;
Switch(audiotype){
Case cupisnthomeSound: M1 = 1;
Case pourActionCompleteSound: M2 = 1;
}
}
Main()
While(1)
{
if (cupIsntHome and cupisnthome audio hasn’t begun)
playAudio(cupisnthomesound);
else if (pourActionComplete and pourActionComplete audio hasn’t begun)
playAudio(pourActionCompleteSound);
}Flowchart
References
- 1. Nuvoton, “Single-chip, Multi-message Voice Record/Playback Device,” ISD1900 datasheet, Jan. 2009
- 2. WT, “Audio-Sound Breakout - WTV020SD,” WTV020-SD datasheet
- 3. Sanco Electronics Co., “Speaker, PCB mount,” EMB-3008A
- 4. Covor Industrial Co., “Thin speaker,” COM-10722
- 5. Sparkfun, “Speaker – 0.5 W (8 Ohms),” BA01282, Online. Available: www.sparkfun.com. on Sept. 25, 2013