Digital Potentiometers

farrelli

Hi, I am new to this forum and in need of some help. I am looking for a digital pot that will allow me to control 555 timers for PWM, however I want one that will use as little of the basic stamp pins as possible, I am using the BS2 module. Any help would really be appreciated, thanks

Henry Casson

I'm just as new as you. The 'what's a microcontroller ' book and the BS2 education kit show a digital Pot called an AD5220 which seems to need 2 pins and power and ground . It seems to provide 128 steps between 78 ohms and 10 K. I did the example program and it worked.However, you might look into doing your PWM with the microcontroller, which makes it really easy. You can get the AD5220 from Parallax for $3.25( I read somewhere)

Mike Green

The smallest number of pins is two. You can use either a pot with up/down pins or you can use an I2C protocol. In the first case, the BS2 code is quite simple. In the second case, the code is more complicated, but you can attach several pots to the same pair of pins. It's much easier to do I2C control with a BS2p/pe/px, but you can do it with a BS2. There's a good Nuts and Volts article with examples (#115) for the BS2.

Look at the Dallas Semiconductor website for a variety of digital pots.