Hello,
It looks like you are trying to adapt one of my example programs to work with 2 ds1621 chips.

First thing to look at is if your hardware has been addressed correctly.

To address the first ds1621 connect pin 7 (A0), pin 6 (A1) and pin 5 (A2) to GND.
This will address the first ds1621 to hex 90.
Hex 90 is the WRITE address of the first ds1621 and the READ address is the WRITE address + 1 (hex 91)
WRITE address is hex 90.
READ address is hex 91.


To address the 2nd ds1621 connect pin 7 (A0) to +5V, pin 6 (A1) to GND and pin 5 (A2) to GND.
This will address the 2nd ds1621 to hex 92.
Hex 92 is now the WRITE address of the 2nd ds1621 and hex 93 is now the READ address.

Also, did you remember to put pull-ups on the SDA and SCL lines?
About 4k7 should been fine.

And now its up to you to look through your software.
I see a small error under **constants**.

Greetings,
Drifter2006