LED and Piezo

arien009

Hi,

May I know what command can I use to get the LED to flash and piezospeakers to beep at the same time? Eg. LED to flash 6 times with 1 second interval, and concurrently piezospeaker to beep with 1 second interval.

Thanks.

Spiral_72

If the led and resistor were connected to PIN2 and the pizo connected to PIN5 =>

If the pizo has a built in oscillator, then you just send it a output:

FOR i = 1 to 6
PIN2 = 1 turns on LED
PIN5 = 1 turns on pizo
PAUSE 1000 do nothing for 1000 milliseconds
PIN2 = 0 turn off LED
PIN5 = 0 turn off pizo
PAUSE 1000
next i



Otherwise you would:
FOR i = 1 to 6
PIN2 = 1 turns on LED
FREQOUT 5,1000, 2000 oscillates pizo at 2000Hz for 1000 milliseconds
PIN2 - 0 turns off LED
PAUSE 1000 do nothing for 1000ms
next i

You'll need to setup your pins as outputs of course. I hope this helps



P.S. yea I didn't use the code feature so all my formatting is gone. sorry.

arien009

Hi, does the boe-bot come with an oscillator?

What if I do not have one?

electrosys

Some piezo speakers has a built in oscillator, they will output a beep if you just connect a relevant voltage to it's +pin and -pin
No, I don't think the beo-bot piezo speakers has a built in oscillator, you have to use the FREQOUT command (look at Spiral_72 code)
You could also have a look at the (What’s a Microcontroller? v3.0 (.pdf) and the ( BASIC Stamp Manual v2.2 (.pdf)

Phil Pilgrim (PhiPi)

There's no reason you can't drive the LED from the same pin you're using with FREQOUT for the piezo. The LED will be driven at the audio frequency but will look as if it's on constantly during those one-second intervals that the piezo is beeping.

-Phil

arien009

thanks people!