Getting the data from HMR3500 Magnetic Compass Module

[jtc]

hello.

We are planning to use a new instrument/sensor that will give us an Azimuth value (0-360deg). The sensor is called TruePoint Digital Magnetic Compass. The maker is Honeywell which they told me they dont have LabVIEW code interface yet. At this moment I have the sensor with me to borrow for a week time. I want to get the data I need (Azimuth) but I do not know how to interpret the data I am getting from the sensor. The connection between my PC and the sensor is via RS232. In my VI (pls see the attached), I can only read the hexadecimal data. I also attached a screen shot file while the VI is running capturing the hexadecimal data.

Using the Sensors Utility software the data coming from the sensor looks the one i attached (log data sample).

This is my first time to encounter hexadecimal data and I have no experience how to interpret or change them to a readable one so that I can pick the data that i need. Can anyone teach me how to decode the data i am getting. I would greatly appreciate any advise. Thanks in advance.

bon

LV8.0

[JasonSmith]

The key to your success is going to be finding a description of the binary data that the compass is transmitting.  Hopefully this is available from Honeywell.  If it is not, then you have a much more difficult task ahead of you, as you will have to attempt to decode the binary data yourself.  This is probably beyond the scope of what I would expect someone on the forum to help you with, unless they have worked with this exact instrument in the past.

Once you know what the data format is, converting it to readable data types is going to consist of extracting the appropriate substrings from your long hex string, then typecasting them to the proper data types.  This is actually fairly simple to do, but only if you have a reference telling you how the output data is formatted.

See if you can find a reference for the data format, and then it will be much easier for me or others on the forum to help you figure out how to extract the data in LabVIEW.

- Jason S.

[jtc]

Hi Jason.

Thank you for your reply and kind advise/s. I have been trying to inquire about the kind of data being transmitted from the sensor to Honeywell (maker) but so far I am not getting any reply. The distributor had given me a 12 page Programming Example in "C" code but I am not familiar with C code or the Message Packet Structure and I still do not understand how to decode it.

I know that I am asking too much but I just need something to start with .

Do you think this 12 page example is all I need to start capturing the data from the sensor?

Any advise I would greatly appreciate.

Thank you very much.

bong

LV 8

[Brian_Beal]

You may be better off posting this question here: http://dtsn.darpa.mil/ibb/categoryindex.aspx?boardID=1.  Some of the Grand Challenge teams used Point Research navigation products.  Some of the teams I talked to mentioned that the units didn't do everything they were advertised as doing.  Also, I'm not sure what effect the Honeywell buyout had on tech support.