Trouble talking to HMC6364 Compass

CountMurphy

I recently purchased this chip in hopes it would be simple to interface with the propeller. The documentation said in order to use the chip, I'd have to:

[FONT=sans-serif]
1. [/FONT][FONT=sans-serif]Appl[/FONT][FONT=sans-serif]y power to the VDD pins (nominally[/FONT]

[FONT=sans-serif]2.[/FONT][FONT=sans-serif]Wait at least 5[/FONT][FONT=sans-serif]00[/FONT][FONT=sans-serif] milli[/FONT][FONT=sans-serif]-[/FONT][FONT=sans-serif]seconds for device initialization. The HMC6343 is in the default Run Mode.[/FONT]


[FONT=sans-serif]3.[/FONT] [FONT=sans-serif]Send 0x32 and 0x50 to command the Heading and Tilt Data to be clocked out next.[/FONT]


[FONT=sans-serif]4.[/FONT][FONT=sans-serif]Wait at least 1 milli[/FONT][FONT=sans-serif]-[/FONT][FONT=sans-serif]second[/FONT] [FONT=sans-serif]to allow the HMC6343 to process the comm[/FONT][FONT=sans-serif]and.[/FONT]


[FONT=sans-serif]5.[/FONT][FONT=sans-serif]Send  0x33  and  clock  back  six  more  response  Bytes  from  the  HMC6343.  These  will  be  the  Heading,  Pitch  and [/FONT]
[FONT=sans-serif]Roll  Byte  pairs[/FONT][FONT=sans-serif];  binary  format  in  tenths  of  a  degree[/FONT] [FONT=sans-serif]with  2’s  compliment  on  pitch  and  roll  angles.  (0  to  3600 [/FONT][FONT=sans-serif]heading, [/FONT]
[FONT=sans-serif]±900 pitch, and ±9[/FONT][FONT=sans-serif]00 roll)[/FONT]


[FONT=sans-serif]6.[/FONT][FONT=sans-serif]Repeat [/FONT][FONT=sans-serif]steps 3 [/FONT][FONT=sans-serif]-[/FONT][FONT=sans-serif]5 [/FONT][FONT=sans-serif]every 2[/FONT][FONT=sans-serif]00 milli[/FONT][FONT=sans-serif]-[/FONT][FONT=sans-serif]seconds or longer to ge[/FONT][FONT=sans-serif]t fresh data from the default 5[/FONT]Hz update rate

Sounds simple right? Yet no matter what I do I only am reading "0" as an output. Could someone please proof read my spin code and let me know if I am doing something really dumb?

CON
  _clkmode=xtal1+pll16x
  _xinfreq=5_000_000

  device=$32 <<1

obj
  serial : "Simple_Serial"
  SN : "Simple_Numbers"
  i2c : "Basic_I2C_Driver"


pub main|X
  serial.init(1,30,4800)
  waitcnt(clkfreq+cnt)
  i2c.Initialize(22)'set our clock plus +1 for sda
  waitcnt(clkfreq+cnt)
  repeat
    i2c.start(22)
    i2c.Write(22,device)
    i2c.Write(22,$50) 'get tilt heading info!
    i2c.stop(22)
    waitcnt(clkfreq/1000 + cnt)     'wait milisecond
    i2c.start(22)
    i2c.Write(22,$33)
    X:=(i2c.Read(22,i2c#ACK) << 8) | (i2c.Read(22,i2c#ACK))
    serial.str(SN.dec(X))
    i2c.stop(22)
    serial.str(string("   "))
    waitcnt(clkfreq + cnt)

I know there are objects to read this chip in the object exchange already, but I couldn't get them working either. Thanks in advance!




Using Basic I2C Routines Version 1.3

Leon

Schematic?

CountMurphy

Leon wrote: »

Schematic?

http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Magneto/HMC6343_v13.pdf


As for how its hooked up, scl is pin 22, and sda is pin 23. Data sheet is here: http://www51.honeywell.com/aero/common/documents/myaerospacecatalog-documents/Missiles-Munitions/HMC6343.pdf

CountMurphy

As of now if the code above is run with the most current i2c Driver it prints out :

0   775   7   1   0   0   7   1   0   0   7   257   1   256   0   1   257   257   1   0   0   0   1   0  .......

Now it prints this with out me touching the compass (stays stationary) so I know these are not proper heading values. If I run the code above using Tim Moore's clock stretching i2c driver I get all zeros. If it helps any I am using this breakout from spark fun https://www.sparkfun.com/products/8656 (so I am assuming I dont need pull up resistors since it works as is with an arduino).

CountMurphy

I've also started playing more with Tim's HMC6343 object code (found here: http://obex.parallax.com/objects/372/) in hoping I could at the very least get that working. Here is my go at it:

CON
  _clkmode=xtal1+pll16x
  _xinfreq=5_000_000

  device=$32 <<1

obj
  serial : "Simple_Serial"
  uarts : "Simple_Serial"
  SN : "Simple_Numbers"
  i2c : "Basic_I2C_Driver"
   i2cObject     : "basic_i2c_driver"                    '0 COG
  hmc           : "hmc6343object"
VAR
  long i2cSCL

pub main|X,Y,Z
  i2cSCL := 22
  ' setup i2cObject
  i2cObject.Initialize(i2cSCL)
  uarts.init(1,30,4800)
  repeat
    hmc.GetHeading(i2cSCL, device,@X,@Y,@Z)
    uarts.str(string("Heading XYZ: "))
    if X < 0
      uarts.str(string("-"))
    uarts.str(SN.dec(||X/10))
    uarts.str(string("."))
    uarts.str(SN.dec(||X//10))
    uarts.str(string(" "))
    if Y < 0
      uarts.str(string("-"))
    uarts.str(SN.dec((||Y)/10))
    uarts.str(string("."))
    uarts.str(SN.dec((||Y)//10))
    uarts.str(string(" "))
    if Z < 0
      uarts.str(string("-"))
    uarts.str(SN.dec(||Z/10))
    uarts.str(string("."))
    uarts.str(SN.dec(||Z//10))
    'uarts.tx(0,13)

This code returns

Heading XYZ: 25.7 25.7 25.7

only when tilted. if i move the compass, I get nothing but zeros again. I dont know what I am doing wrong, and the device itself works with my arduino uno, so I know the chip isn't bad. I've also tried using different pins on my prop for the i2c communication but that didn't give me different results either.