topic Re: i.MX51 buzzer driver using IO in i.MX Processors

i.MX51 buzzer driver using IO

alsaleem — Sun, 30 Oct 2011 23:00:44 GMT

Hi,

Is there a way to output a variable frequency signal (audio range, 200-4K) square wave from i.MX51 to drive an external buzzer?

Thanks.

Re: i.MX51 buzzer driver using IO

JerryFan — Wed, 02 Nov 2011 05:26:38 GMT

PWM was recommended for this case. It is more accurate and need less arm core's involvement.

Re: i.MX51 buzzer driver using IO

alsaleem — Wed, 02 Nov 2011 05:45:44 GMT

The driver only allows to set the pulse width not frequency (fixed on initialization) using brightness. How do I change the PWM frequency?

Thanks.

Re: i.MX51 buzzer driver using IO

JerryFan — Wed, 02 Nov 2011 07:49:39 GMT

That's right, PWM is designed for brightness tuning, but it can also be used flexibly. Actually, the PERIOD can be programmed (see Chapter 47.2.2.5, mx51RM for the detail.) and the frequency is much accurate that GPIO way. Anyway, if the accuracy is not important, such as for a buzzer, the GPIO method should be OK.