> I am trying to interface a ds1624 to a pic 16f84. Here is my problem..
> picbasic wants to send a control byte the highest bit of which says
whether
> the following address variable is to be sent as 8 or 16 bits. The example
> they give is using an eeprom. The control variable for it is %01010000 the
> device code is the 1010 and the pin straps are the 000 on the end. They
add
> a 0 on the front end because the address to be sent is only 8 bits.  A
> ds1624 however has a device code of 1001. I have my straps set to 010.
But
> it needs one more bit(the least significant) to tell it whether the
command
> is to be writen or read to the ds1624.  The "control" variable is only 8
> bits so my byte would look like %1001010x. I am pretty sure the address
for
> the ds1624 is 8 bits.  but this would configure it to 16.  How can I fix
> this?  Has anyone out there interfaced a ds1624 and picbasic?
>
I took a quick look at the datasheet and I would try the following
The control byte contains a 4 bit control code which is '1001' for read and
write operations.
The next 3 bits are the device select bits, in your case '010' (A2/A1/A0).
The last bit is a '1' when a read operation will be performed, else '0' for
write.

So to start you send a 'start' condition on th I2C bus
    High SDA
    High SCL
    Low SDA
    Low SCL

Now we send the control byte
    Send out %10010100
    (Meaning 1001 = control code / 010 = device select / 0 = write
operation)

Wait for ack ....

Send command to DS1624 ...

Hope this helps,
    Thierry Vanmarcke