Arduino Forum

Using Arduino => General Electronics => Topic started by: chaosmoon on Jan 31, 2011, 02:41 am

Title: 4051 s0,s1,s2 pin jitter
Post by: chaosmoon on Jan 31, 2011, 02:41 am
i'm building a simple midi fader box with an ATmega328 and 4051 multiplexer.The analog input goes bananas if i get close(with my hand) to the 4051 "input select" pins or their digital inputs on the ATmega. So far(since this pivture was taken) i've added a 103 capacitor between Vcc and GND on the 4051 and a 104 between AREF and GND on the ATmega.

(http://chaosmoon.info/sf/midifader01.jpg)
Title: Re: 4051 s0,s1,s2 pin jitter
Post by: RuggedCircuits on Jan 31, 2011, 02:48 am
Those pins are inputs to the 4051, so they need to be outputs of the Arduino (not inputs). I'd recommend 10k resistors on each of those pins to GND. It might be your outputs (inputs?) are floating.

--
The Rugged Motor Driver (http://ruggedcircuits.com/html/rugged_motor_driver.html): two H-bridges, more power than an L298, fully protected
Title: Re: 4051 s0,s1,s2 pin jitter
Post by: chaosmoon on Jan 31, 2011, 03:03 am
aah yes inputs..10k resistors. check.
will do after some sleep, its 3.a.m.
Title: Re: 4051 s0,s1,s2 pin jitter
Post by: chaosmoon on Jan 31, 2011, 03:36 am
no sleep till brooklyn.

the 10K resistors fixed it, thanks