MCP41100 Digital Pot. IC help Please

No

hi,

Im having bit of a trouble programming this MCP4110 digital potentiometer. I have it hooked up per spec sheet(javascript[noparse]:o[/noparse]penreq('http://www.datasheetcatalog.org/datasheet/microchip/11195c.pdf') Pin 1,4,7 connected to VSs. 8,5 to Vdd. Pin 2, and 3 to bs2 pins(0,1). And pin 6 to the positive lead of my voltmeter, neg lead attached to Vss. i get a read out of 2.48V, which im assumin is the mid range voltage.

What i did was sent a low signal the SCK pin(2 of IC) , then a pulsout command to the SI pin(3 of IC), then sent a high signal to SCK pin (2 of IC).

Low 0
Pulsout 1,5
high 0

In the data sheet is says it execute the command on the rising edge of the Sck pin which woukld mean that the wiper wouldnt shift till the SCK goes from a low to High?

Should i be using a·pulsout command for this specific IC?

I noticed that the internal schematic looks a but more complex as oppose to the AD5220. Can anyone help?

Erik Friesen

This will take a modification of an spi routine that you should be able to find in the object exchange or perhaps in your bs2 programs. There is a fair bit of documentation on the use of SPI but I don't recall seeing any directly dealing with this chip. I have used this chip with the propeller with success. It will take a bit of study on the datasheet to get the communication down but it shouldn't be too hard.

No

thanks for the input. Ive been lookin over the datasheet today while at work, i have a few things im gonna try when i get home, ill keep ya posted on how it turns out.