HM-55B Compass Help
Hello,
·· I recently purchased a BS2-SX Stamp, Super Carrier Board and the HM-55B Compass Module to play with.· My first compass module seemed to work·(sending data to debug) and then stopped working altogether so I ordered 2 more just in case one of them went bad again.· I got the new modules in and started playing with them today and they wouldn't work either.· I found out that none of them will work while I have the EN (NOT)·connected to the Stamp (P4 on the stamp).· This is supposed to be the Reset Line that works with the·Shiftout command to prepare the HM-55 to receive data from the stamp.· Once I disconnect this line it starts working and continues to send data to the debug window.. providing a heading from the HM-55. even without this·wire connected.··It seems irratic because I can see the RCV light in the debug window and I only get updates every now and then.· I also get updates faster in some areas than in others when I am rotating the breadboard.· The data stops altogether when I reconnect the EN wire back to the HM-55 and even resetting the stamp doesn't get the data going again until I remove the wire.·
I don't think it's loose wires because I've checked them a zillion times already...· Has anyone else played with this module and experienced the same problems?
I am using the code provided on the Parallax site for the HM-55B module testing / calibrating and I even tried the HM-55 Grapical Program... it doesn't seem to work either.
Any ideas on what could be going on here?
Cheers,
Dave
·
·· I recently purchased a BS2-SX Stamp, Super Carrier Board and the HM-55B Compass Module to play with.· My first compass module seemed to work·(sending data to debug) and then stopped working altogether so I ordered 2 more just in case one of them went bad again.· I got the new modules in and started playing with them today and they wouldn't work either.· I found out that none of them will work while I have the EN (NOT)·connected to the Stamp (P4 on the stamp).· This is supposed to be the Reset Line that works with the·Shiftout command to prepare the HM-55 to receive data from the stamp.· Once I disconnect this line it starts working and continues to send data to the debug window.. providing a heading from the HM-55. even without this·wire connected.··It seems irratic because I can see the RCV light in the debug window and I only get updates every now and then.· I also get updates faster in some areas than in others when I am rotating the breadboard.· The data stops altogether when I reconnect the EN wire back to the HM-55 and even resetting the stamp doesn't get the data going again until I remove the wire.·
I don't think it's loose wires because I've checked them a zillion times already...· Has anyone else played with this module and experienced the same problems?
I am using the code provided on the Parallax site for the HM-55B module testing / calibrating and I even tried the HM-55 Grapical Program... it doesn't seem to work either.
Any ideas on what could be going on here?
Cheers,
Dave
·
Comments
Are you thinking differently?
If looks as if you are using the schematic for the SX interface which says RB4 in the document.
The BS2 schematic stays off the ground pin and has software toogle the EN/
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"If you want more fiber, eat the package.· Not enough?· Eat the manual."········
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Chris Savage
Parallax Tech Support
csavage@parallax.com
·· I was referring to the HM-55B manual where PIN 1 & 2 are Din / Dout respectively, Pin 3 is ground, pin 4 is CLK, Pin 5 is /EN, pin 6 is Vcc....· I am using the 3-wire interface where P6 of th stamp goes to Din/Dout (pin 1&2 HM-55), P4 goes to pin 5 (/EN) and P5 goes to CLK...
I have tried the code on P0 - P3 and P7-P9 (Stamp Pins) with the same results and have tried·both of the brand new compass modules with the same results.· I thought I might have damaged the I/O pins on the Stamp until I accidently removed the /EN pin from the HM-55 module and it started working.· Everytime I have the /EN pin hooked up the compass module stops working.· As soon as I remove it, the debug window shows heading information but is not consistantly·receiving information...· It is also not very accurate and jumps around a lot when it does send information.· Even if I am not moving the module.
Dave
··· Just to confirm...Are you using code from our webiste or code that you typed in?· Also, is the code unmodified, except for the pin number changes?· If this is the case please call our Tech Support Dept. tomorrow and we'll see if we can't work this through on the phone.· Take care.
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Chris Savage
Parallax Tech Support
csavage@parallax.com
Do you have to calibrate the compass before you run the graphic display?
I can call tech support tomorrow as you suggested but I work during the week so I won't have the compass or code in front of me.·
Just to clarify, I bought the first module from Jameco,· and the second two modules directly from Parallax.· Was there a firmware change or board layout change recently that would affect the /EN pin?· The first module worked with the /EN pin if I remember correctly... before it quit working.
Thanks,
Dave
The graphical app won't work if the stamp is already talking back via the debug terminal. Make sure that you have the debug terminal closed before you run the compass exe file.
Make sure you have the correct COM port selected, and the correct Baud rate set as well.
Ryan
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Ryan Clarke
Parallax Tech Support
RClarke@Parallax.com
·· Roger that.· I did have hyperterminal working because it seemed to allow for faster updating than the debug window but I shut down the port before I opened the graphic copmpassviewer.· It didn't work at all... is it supposed to be a real time update in the GUI or does it update once and then you have to start the program again?· I would figure it would show the little ball turning and the heading in the middle as a real time update as you turn the compass...·
Maybe I am just seeing noise... I don't know... but I do know that I don't get anything unless the /EN wire is disconnected.· I'll try to·borrow an o-scope from work today to see if I can look at the signals.
Cheers,
Dave
·
The Compass app should update real-time- (you spin the compass, the dot in the window moves, as fast as you can spin it)-
Just to clarify: you can see data from the debug terminal? Do the values change when you spin the compass? Are they consistent?
Ryan
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Ryan Clarke
Parallax Tech Support
RClarke@Parallax.com
·· The app doesn't move at all, it gets stuck at 22.5 degrees and displays 7219 degrees in the center.
The debug window DOES display data.. the values change but are not very consistant.· It reads close to what my magnetic compass is reading.. for example if I am at 180 degrees it will read 166, 188, 202, 0,0,180,0,177.....bla bla and continue but never dead on... it does come up with a lot of zero's though.· In some areas of the rotation it doesn't send data at all and sometimes it will get stuck at a certain point.. like 172 degrees for the whole 180 to 270 range of the circle... then no data... then once i get back to 180 it will start sending again.· Weird..· but all of this only works when I have the /EN wire disconnected.
If I connect the /EN wire to the Stamp it stops sending data...· I tried using a pull down resistor between ground and the /EN pin and it stops sending data as well... even with the Stamp connected.
I'm gonna try to call tech support since you are open 3 hours longer than I work (relatively)...I'm on th East Coast.· [noparse]:)[/noparse]
-Dave
·
·· Update on this:· I called tech support and spoke with one of the Parallax guys there.· While I was on the phone he told me that since I was using a BS2-SX that the chip was running too fast for the code the way it was written... at the same time he was telling me this my BS2-SX chip went up in smoke for some reason.· I didn't change anything and it was set up the same way it had been for the past week plus.· Dunno what happened there.....
He told me that he was going to send a new BS2 to me in the mail so I could get this working·and I just got back off of my business trip and here it sits.·[noparse]:)[/noparse]· I'll be making sure that the Super carrier board wasn't damaged when the BS2 smoked and then I'll try this setup again.
Thanks Parallax for the super support so far!· [noparse]:)[/noparse]
Dave
*Edit*· I didnt see the BS2 that was shipped and was asking about it, then I found it stashed away under another pile of mail.· Sorry...
Post Edited (toofastdave) : 7/21/2006 3:07:55 AM GMT