It running at 12MHz.
I'm making a soccer robot.
The serial data is the light sensors values.

WHEN it detected the ball, the 89C2051 will send the state of the FOUR light sensors value to the 89S52 at MODE 1, 62.5kbps.

After detected the ball, says the right light sensor detected the ball, it have to do a right turn UNTIL the front light sensor detect the ball, which means the ball is in front of it now. But THE PROBLEM is when it detected that the ball is on its right hand side, it turn and TRY to read the NEW data from the SBUF, but it does NOT refresh the values of the light sensor.

Stanley