H48C 3-Axis Accelerometer

Ritu

I am trying to program the Hitachi H48C_3-Axis with the Javelin, so I need to code in JAVA and the example given on the parallax website is in Basic, and I am having a hard time converting it to JAVA, is there anyone who would know how to have the accelerometer supply information to the Javelin in the programming language JAVA.
Thanks

Peter Verkaik

This should get you going.
regards peter


Post Edited (Peter Verkaik) : 6/30/2006 8:59:59 AM GMT

Ritu

When I try to run this an error comes up, [noparse][[/noparse]Error JVM-0029} Method H84C_test::gForce contains out of range(Integer 55296) How could I fix this?
Thanks

Peter Verkaik

Fixed version attached.

regards peter

Ritu

Thanks for all you help, sry but one more question. I seem to keep getting just 0 for the x, y, and z, even when I move it. What could be the problem there, bad wiring?
Thanks again

Peter Verkaik

Try changing the CPU.POST_CLOCK_MSB into CPU.PRE_CLOCK_MSB and see
what results that gives.
regards peter
·

Ritu

Hmm I am still getting just 0s, it might be my wiring but I am not sure.
Thanks anyway

Peter Verkaik

Make sure both the H48C and the javelin share the same GND.
regards peter

Ritu

Hmmm, I have no idea why it still isnt working.

Ritu

Anyone have any more suggestions, I dont think it is the wiring anymore, but something in the code.
thanks

Peter Verkaik

Have you tried the basic code using a basic stamp?
If not, it could be a bad chip. Do you have another chip?

regards peter

Ritu

I only have the javelin, and I have gotten other programs to work on it, so I am pretty sure the problem is in the code.
Thanks

Chris Savage

Ritu,

·· Juts because the Javelin works fine doesn't mean something hasn't hapened to the Accelerometer, which is what Peter is suggesting.· By trying known code on a BASIC Stamp that would help narrow things down.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support
csavage@parallax.com

Ritu

K I tried it with the basic stamp and it works, so I am still confused about the java code.

Peter Verkaik

Ok, try the attached program.
I added debug statements to print the refValue and adcValue for each reading.
Let us know if these values are always -1 as they are preset,
or if they have other values which indicates bits are read.
Edit: and notice I used pins 13, 14 and 15.
Change that to the pins you used in your wiring.

regards peter

Post Edited (Peter Verkaik) : 7/6/2006 8:24:25 PM GMT

Ritu

Everything is zero, not -1
thanks for all the help you have given me so far

Ritu

Actually no, the refValue and the adcValue equal 1

Peter Verkaik

In the basic code there was no initialization for the clock and datapin.
The documentation for the javelin shiftIn() and shiftOut() tells such
initialization is required.
Try the attached program. I added initialization code at the start of main().
If results remain 0 or 1 for adc and ref, try other combinations for the
clk and data init values.



regards peter

Ritu

Hmm still doesnt work, no matter what combination I did of true and falses.
thanks

Peter Verkaik

And you are absolutely sure you didn't
interchange the clock, data and cs pins?
If the basic stamp worked, and you use the same
socket for the javelin and the same pin definitions
(so you know the wiring is correct), then it should work.

Edit: unless one of the used javelin pins is defect.
Have you tried pulsing a led on the clock, data and cs pin,
and have tried to read a button on the data pin?
Just to make sure your javelin pins·are ok.

regards peter

Post Edited (Peter Verkaik) : 7/7/2006 2:18:52 PM GMT