Thanks a bunch :-)

Anyone got a Quadrature encoder up and running on the Due ?
Can you share the setup ?
The tables and the timer (TC) are somewhat bewildering to me and I cannot find any examples on Atmels website for the SAM3X chip that shows any source code

Cheers
K

Might be worth to try it with a SR Latch on the input.
This way it would eliminate any input issues

You properly should not do anything like serial.print inside the ISR.
Just set a flag and print elsewhere.
I think print is buffered or something as the code locks up on a mega when triggering the interrupt.

On the 8bit Arduino boards I have, the firmware appears to be doing something strange at each startup, so could be tied up with that.
I will try to run your code on another board when I get home tonight.

I haven't got a Due board, so Im guessing.

Is the 2.5V well within the specs for a high ?, maybe try 3V

Are the other pins floating, try tying high or low

Have you tried on another board, ie 8 bit, whats the result ?

Also on the output shown, is that without pressing the button at all ? like never pressing the button

Just really my lack of knowledge of C, but its improving heaps

Thanks

Main reason is debugging really, dump 50 bytes etc., but also after speed, tho with the 32bit Due this is probably not going to be much of an issue.
But you are right, I do get flashbacks, lots at times.

Do I have to do it in Assembly or can this be done in C ?

How do I assign variables to a fixed location in ram in C ?

I have a quite a few variables declared as static and what I would like to do is to place these variables in a set order and then later send these via serial in a set order by starting a ram address xx

Or should I just let the compiler take care of this ?

Ta

Kim

Thanks

Coming from Assembly and a bit of basic, I'm trying to get my head around the GNU C compiler and the way it does things.
Been reading the GNU documentation, but sometimes it is "clear as mud" :-)

K

Interesting and thank for clarifying this.

One question tho

When allocation static memory does that automatically become a global variable ?

Kim

There is a great tutorial on youtube which explains all the basic operations of the DC Motor.

I think its important that the Library be made so it can run as a background task in a scheduler.
Also that the auto transmit messaging be selected to be optional as sometimes you don't want it to keep transmitting.

K

Maybe some consideration should be given to a "Time Triggered" OS
Link here to a free book
http://www.tte-systems.com/books/pttes
Also they have quite a few seminars on YouTube.

Their hybrid system is a co-operative scheduler with just one interrupt.
This system gives a lot of predictability (in terms of time) and by allowing just one interrupt, all the issues relating to pre-emptive multi-tasking are virtually bypassed.

Their system is often used in safety related applications, ie car, planes,

Here is a link to a port to Arduino (well a beginning anyway)
http://chrisbarlow.wordpress.com/2012/09/13/reliable-task-scheduling-with-arduino-avr/#comments

Just my 2c

Kim

Well, from what I can gather, I properly need to update speed/count/corrections every 1mS or so.
It seems that generally a PI function is used, instead of a PID, when it comes to motor control.

I'll spend some time trolling through PIC, Freescale, etc website looking for papers.
Some of the specific motor control chips may have some S/W that I can look at.

Thanks for the AccelStepper suggestion. Their site has some good stuff and the forum is usefull :-)
in case someone else is looking, here is the link
http://www.open.com.au/mikem/arduino/AccelStepper/

K