Assembler routine within Arduino Code.

Forum 2005-2010 (read only) Software Syntax & Programs
1

I have a clock signal of 90 khz and need to read the data.
So far I have not been able to get my code quick enough to read the data.

Is it possible to branch from the Arduino's code to an assembler routine and back to the Arduino's code.

The psudeo code is somethin like this

Wait till clock low for 100 ms 
   jump to assembler routine
      loop 20 times
           on clock falling edge read data 
           if data = 1 
             result = result +1 
            else 
             shift left result 
      end loop
   end assember routine
serial.print(result)
2

Yes, it's possible to call pure assembly functions. The rules for doing so are described here:

http://www.nongnu.org/avr-libc/user-manual/FAQ.html#faq_reg_usage

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3

Of course it is possible. For a very quick and dirty example have a look here
http://www.arduino.cc/playground/Main/LogicAnalyzer

Udo

4

Thanks chaps.

Been busy tidying the house after the earthquake. 7.1 about 30 km from our house ! No real damage to our place but quite a lot to may others.

I have downloaded the AVR instruction set and some intro to assembler documentation. I'll try and process this all.

Cheers Wallace

5