Note on Download Speed
----------------------

Some people reported problems with a "receive status error" while
downloading Hex-files to EyeBot, escpecially when using the new binary
format (generated by srec2bin), which should reduce the time needed for
download by a factor of 2.5. (A RoBios-Version of 4.0 or higher is
needed.)

The problem is caused by odd baudrates on both, EyeBot and the sending
PC. On the EyeBot, the baudrate of the Serial_1-port is derived from the
CPU clock. Depending on the frequency of this clock, the 115 kbaud can
be generated more or less preceisely. Have a look at the following table
showing the
percental errors:

CPUfreq Div   act.Baud  Error
----------------------------------
16777   5       104856  9,9%    -
17826   5       111413  3,4%    ok
18874   5       117963  2,3%    ok
19923   5       124519  7,5%    -
20972   6       109229  5,5%    -
21469   6       111818  3,0%    ok
22020   6       114688  0,4%    ok
23069   6       120151  4,1%    ok
24117   7       107665  7,0%    -
25166   7       112348  2,5%    ok
26214   7       117027  1,6%    ok
27263   7       121710  5,3%    -
28312   8       110594  4,2%    ok
29360   8       114688  0,4%    ok
30409   8       118785  3,0%    ok
31457   9       109226  5,5%    -
32506   9       112868  2,1%    ok
33554   9       116507  1,1%    ok
34603   9       120149  4,1%    ok
35652   10      111413  3,4%    ok
36700   10      114688  0,4%    ok
37749   10      117966  2,3%    ok
38797   11      110219  4,5%    ok
39846   11      113199  1,8%    ok
40894   11      116176  0,8%    ok
41943   11      119156  3,3%    ok

The allowed deviation is less than 5%, assuming a PC sending at exactly
115200 baud. Depending on the crystal precision of the EyeBot and the
baudrate generator on the PC, even a smaller deviation can cause
problems. In some cases, even when the deviation is slightly too high,
transferring ASCII-Hex-Files works, since in these files all characters
are 7-bit chars only. Transferring binary files, which contain 8-bit
chars might fail however!

To solve the problem, just select a "better" CPU frequency, which can be
entered in the info_type entry of the HDT for the robot (use the two
first digits of the desired frequency, e.g. 33 for 33554 kHz).
________________________________________________________________________
 Michael Kasper, Universitaet Kaiserslautern, 2002
