# Extra LEDs and Buzzer control from VOXL 2 J3/J5

Source: https://forum.modalai.com/topic/1789/extra-leds-and-buzzer-control-from-voxl-2-j3-j5
Category: VOXL 2 and VOXL 2 Mini (https://forum.modalai.com/category/26/voxl-2-and-voxl-2-mini)
Tags: voxl-2
Posted: 2023-02-07 09:23:15 UTC by Byron_Ch
Replies: 5 · Views: 1445

## Byron_Ch · 2023-02-07 09:23:15 UTC

Hi Modal AI team,
I have an extension board that connect from VOXL2 J3/J5 to control extra LEDs and a buzzer, what GPIOs can control LEDs and any PWM output can control buzzer?

## Reply by Vinny (ModalAI staff) · 2023-02-07 16:12:23 UTC

@Byron_Ch Hi,
All the signals (GPIOs) on J3 and J5 are native 1.8V with only about 2-4ma drive. Please use a FET or other driver/buffer to drive any LEDs or buzzers.
We don't have any true PWM signals on those interfaces. Usually buzzers are just a few KHz and not duty cycle sensitive, so you could get away with a software routine to toggle the gpios. 
An alternative is a simple MCU or I2C to PWM/GPIO IC that can easily do all that too.
Adafruit sells a good I2C to PWM breakout you can experiment with.
Hope that helped.

## Reply by Byron_Ch · 2023-02-08 04:58:29 UTC

Hi Venny,
Very thanks.

## Reply by Ray.Liao · 2023-02-10 02:00:28 UTC (in reply to Vinny)

@Vinny Hi,

Based on Byron question.
We will have a extension board to connect VOXL2 J3/J5, the extension board will redirect to the  Microhard Add-On Board. 
So several pins of J3 connector will be occupied by Microhard Add-On Board. 
I know that J3/J5 connector already have some GPIO defined 

Could you help us to know has current system image already config that GPIOs?
We want to use some GPIO pins(at least 6) for further control. 
Could you helps us check which GPIOs allow us do that?

## Reply by Vinny (ModalAI staff) · 2023-02-11 15:54:06 UTC (in reply to Ray.Liao)

Hi @Ray-Liao 
I'm not in SW, but I think this will help.
https://docs.modalai.com/voxl2-linux-user-guide/

## Reply by Ray.Liao · 2023-02-13 06:04:51 UTC

Hi @Vinny ,

Thanks for your information, 
I already know current GPIO status.