SparkFun Forums

[toneskater]

Hello World
I have a problem with msp430 microcontroller f2013
I'm a student, and I can not find what I need.
I downloaded all the manuals, and I understand in theory what should I do, but in practice I can not write the code.
I want to write c code to read an external voltage to analyze a signal, and insert it in any register of the microcontroller in order to use it later. Do not think that I have not tried to do it, I downloaded numerous examples, but unfortunately do not know where to begin. Can you give me a hand?
Andrea

[toneskater]

I write this code:

Code: Select all

SD16AE = SD16AE3;                 //External input from channel 3
  	SD16INCTL0 = SD16INCH_3;    // Input control register
  	SD16CTL =                  // Control register
   		0 +                      //   clock divider
      	0 +                	 //   low power mode (for enable SD16LP)
        0 +                      //   clock divider
        SD16SSEL1 +              //   use ACLK 
        0 +                      //   V(MID) buffer off (not in 2013?)
        SD16REFON +              //   reference on
        SD16OVIE ;               //   enable overflow interrupt
  	SD16CCTL0 =                 // Channel 0 control register
    	SD16UNI +                 //   unipolar mod
      //SD16XOSR +                //   extended mode, 1024 sampling
      	SD16SNGL +                //   single conversion
        SD16OSR1 + SD16OSR0 +    //   32 oversampling
        SD16LSBTOG +                       //   don't toggle on SD16MEM0 reads
        SD16LSBACC +              //   read the low order 16-bits
        0 +                       //   offset binary, not 2s complement
        SD16IE +                  //   interrupt enable
        SD16SC ;                  //   start conversion
    volt = SD16MEM0 

and then i connect the positive and negative cable to the corrects pins
There are any error??[/code]

[fll-freak]

A couple of things I noticed.

1) You did not show instructing the MSP that the pin you want to use is assigned as a peripheral and not GPIO. Read the section on GPIO in the user's manual.

2) You request the conversion and then immidiately ask for the converted value. The ADC is fast, but not that fast. You should either delay a while, or better yet, ask for the conversion complete to generate an interrupt. Inside the interrupt handler you can copy the value from the ADC to your memory.

[Philba]

there is a lot of sample code available on the TI site. It's been a while since I used the ADC on that chip but I recall starting with TI sample code. You might have to dig around a bit unless they've improved the site.