HMR3500 User's Guide
Request Data: None
DPOWER Wakeup Message
The compass sends the DPOWER message upon power-up, hardware or software reset, and whenever it receives a
POWER request message from the host. The reply data is a readable string of ASCII characters, terminated with a null. In
addition to establishing copyright rights, this message also serves as a diagnostic aid since it is easily seen on a terminal
emulator. An incorrect baud rate, parity, etc., will generate garbage characters; these should be readily recognizable.
A sample wakeup message might be:
0x0d, 0x0a, "~Copyright © 2000-2002 Point Research Corp. COMPASS Vrsn. 1.00CD"
The message ends with the firmware version, both major and minor, and suffixes which indicate build options which were
in effect, information which could be helpful to Honeywell for diagnosing problems.
However, do not try to process this string with software. All information in it, and then some, is also available in the
DVRSN message described on page 13.
Set Baud Rate
Request Data: 1 byte:
A few milliseconds after sending the DBAUD acknowledgment, the compass will switch the baud rate for both sending
and receiving to the new rate. Any messages being received by the module during this switch will be lost. When the host
requests a baud rate change, it should send no other messages for at least 25 milliseconds after the acknowledgment has
Baud rate changing has no effect on other compass operations. Dead reckoning, etc., continue uninterrupted.
If a value other than 0 through 3 is supplied, the DBAUD reply is the code for the current rate, and there is no change.
A baud rate set with the BAUD command has no effect after a reset or power-up, both of which restore the default baud
rate for which the module is configured at the factory. This will be 9600 baud unless other arrangements have been made.
Requested baud rate. Codes are:
0 = 4,800 baud
1 = 9,600 baud
2 = 19,200 baud
3 = 38,400 baud
New baud rate. Codes are same as above.