Re: [Gumstix-users] Using the PCF8591 A/D driver

[Neil C. <nc...@ba...>]

Got a step further.

Loaded the module
modprobe pcf8591

now see a device in sys/bus/i2c/devices/0-0048

However looking at the wiki "program for interacting with I2C devices"

I don't have the I2C program. 

I also dont see the SCLK signal change  state apart from at boot up 
(though I don't expect it to if I cant execute i2c)

So how do I compile i2c in build-root?

Neil
 
Neil Cobbett wrote:
> Hi,
>
> Can anyone tell me the best way to connect to the PCF8591 A/D chip.
>
> It's an I2C A/D D/A 8 bit convertor.  I have wired it all up on breadboard but I am now at the satge of trying to access the device.
>
> I've read the wiki on I2C and see you can access the registers but I also notice there is a specific kernel module.  I have compiled this in to my kernel.
>
> Can anyone tell me how to load the module and what commands I need to use to access the device A/D lines?  There is a way of it polling each A/D in turn.  If this can be done automatically and then I just read a register for the value then that would be great.
>
> So how does the PCF8591 driver integrate with the other I2C modules?
>
> Many thanks
> Neil
>
>
> ____________________________________
>
>    Neil Cobbett    BENG MIET
>    Research Engineer
>    British Antarctic Survey
>    Physical Sciences Division
>    High Cross
>    Madingley Road
>    Cambridge
>    CB3 0ET
>
>    Telephone : +44(0) 1223 221585
>    Fax: +44(0) 1223 221226                         
>    E-Mail: nc...@ba...       
>    Web: www.antarctica.ac.uk          
> _______________________________________
>   


--  
This message (and any attachments) is for the recipient only.  NERC is subject
to the Freedom of Information Act 2000 and the contents of this email and any
reply you make may be disclosed by NERC unless it is exempt from release under
the Act.  Any material supplied to NERC may be stored in an electronic
records management system.