Pages: [1]   Go Down
Author Topic: Trying to understand the CAT9532 i2c IC.  (Read 953 times)
0 Members and 1 Guest are viewing this topic.
Scunthorpe, UK
Offline Offline
Full Member
***
Karma: 0
Posts: 129
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Hello all.

Am trying to understand how to use the CAT9532 IC so hope someone can help. Am i correct in thinking that you have to send 2 bits of data per i/o pin and can i send a big hex number to control all 16 i/o's in one transmission for example 0x55555555 (to turn all outputs on) or do you have to split it down to 4bytes?

http://www.onsemi.com/pub_link/Collateral/CAT9532-D.PDF

Thanks.
« Last Edit: October 05, 2012, 03:11:32 am by Pavilion1984 » Logged

Switzerland
Offline Offline
Faraday Member
**
Karma: 112
Posts: 5281
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
you have to send 2 bits of data per i/o pin

Yes.

Quote
can i send a big hex number to control all 16 i/o's in one transmission

No.

Quote
do you have to split it down to 4bytes?

Yes, you have to send 4 bytes because you have to send everything split up into bytes over the I2C.

On page 11 of the datasheet you'll find an example of a complete command operation. The right column shows the data going over the I2C channel. Keep in mind that although the address data going over the I2C channel is 0xC0 (in the example), you have the specify the 7bit address (0x60) to the Wire library.
Logged

Scunthorpe, UK
Offline Offline
Full Member
***
Karma: 0
Posts: 129
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Ok thats great. Hmmm, i don't need all the blink stuff so might be better going for a basic i2c expander chip for eaiser coding.

Thanks.
Logged

Pages: [1]   Go Up
Jump to: