Producing a square wave on a gumstix GPIO
|
View:
New views
3 Messages
—
Rating Filter:
Alert me
|
 |
Producing a square wave on a gumstix GPIO
by Scott Harris
::
Rate this Message:
I need to generate a square wave on a gumstix GPIO pin in order tor drive a piezo buzzer for user feedback. I'd like to achieve this in python if possible, but I'm not averse to writing some C code to do fiddle with pxaregs. I also need the beeper code not to block my main python loop, since that code is pretty busy.
Does anyone have some suggestions on a minimum hassle path to achieve this? Thanks, -Scott ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ gumstix-users mailing list gumstix-users@... https://lists.sourceforge.net/lists/listinfo/gumstix-users |
|
|
Re: Producing a square wave on a gumstix GPIO
by Ryan Rapetti
::
Rate this Message:
Maybe a second thread to do the beeping? Then the main thread just
signals. I'd still worry about the buzzer thread getting preempted
though. Now that I think about it, the serial port produces a nice
clean square wave. By playing with the data and the baud rate you could
probably make it work ok. Then all you need to do is write the proper
data to the buffer and be on your way. You'd need an amplifier circuit
to isolate the UART from the buzzer, but an op-amp or a properly wired
transistor should work nicely for that.
Ryan Scott Harris wrote: I need to generate a square wave on a gumstix GPIO pin in order tor drive a piezo buzzer for user feedback. I'd like to achieve this in python if possible, but I'm not averse to writing some C code to do fiddle with pxaregs. I also need the beeper code not to block my main python loop, since that code is pretty busy. ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ gumstix-users mailing list gumstix-users@... https://lists.sourceforge.net/lists/listinfo/gumstix-users |
|
|
Re: Producing a square wave on a gumstix GPIO
by gumstix_user
::
Rate this Message:
If you are doing low frequency stuff you can treat the GPIO lines as files. They are located in /proc/gpio
just open the I/o line you want such as "/proc/gpio/GPIO66" etc and then fprint or fwrite "GPIO out set" or "GPIO out clear" to set the logic level for that bit. Sometimes you may need to change the tristate state of the line before you use it. This can easily be done with a script.
|
| Free Forum Powered by Nabble | Forum Help |