C2000 Piccolo - blinking an LED

Ok, this is my first program with the C2000 Launchpad, so I would start with something really basic, the MCU "Hello World" : Blinking an LED.

First of all, let's add the basic things we will probably always need :
We need the basic header file, we probably need to set the clock (clk + pll), stop the watchdog and access the gpio to blink the LED.

I recon we could start with something like this :


#include "DSP28x_Project.h"     // DSP28x Headerfile

#include "f2802x_common/include/clk.h"
#include "f2802x_common/include/gpio.h"
#include "f2802x_common/include/pll.h"
#include "f2802x_common/include/wdog.h"



void main()
{

 WDOG_Handle myWDog;
 myWDog = WDOG_init((void *)WDOG_BASE_ADDR, sizeof(WDOG_Obj)); 
 WDOG_disable(myWDog);
}

I know, this does not do much, right?
Let's see how we can add some more interesting stuff

  CLK_Handle myClk;
  PLL_Handle myPll;
  myClk = CLK_init((void *)CLK_BASE_ADDR, sizeof(CLK_Obj));
  myPll = PLL_init((void *)PLL_BASE_ADDR, sizeof(PLL_Obj));


 //Select the internal oscillator 1 as the clock source
   CLK_setOscSrc(myClk, CLK_OscSrc_Internal);

The clocking user guide states that there are two internal oscillators, both working with a base frequency of 10MHz, there are obviously also external options which we will not consider for this experiment.
To select the second internal oscillator we should use "CLK_Osc2Src_Internal"
Based on the oscillator frequency (10MHz if internal) the PLL (each internal oscillator has a pll) can be configured to set a multiplier and divider.

 PLL_setup(myPll, PLL_Multiplier_12, PLL_DivideSelect_ClkIn_by_2);
// the demo program states : 
// Setup the PLL for x10 /2 which will yield 50Mhz = 10Mhz * 10 / 2
// it looks more a 10MHz * 12 / 2 = 60 to me, which is the max speed of this device (and the multiplier_12 is the maximum value found in the enum declared in the header file)

the multiplier has a value from 1 to 12 and the divider can be 1,2,4.

The blue leds installed on the board (C2000 launchpad) are connected to gpio 0,1,2 and 3.
We will just use gpio_0, so let's configure it as output gpio pin.

 GPIO_Handle myGpio;

 myGpio = GPIO_init((void *)GPIO_BASE_ADDR, sizeof(GPIO_Obj));

 GPIO_setMode(myGpio, GPIO_Number_0, GPIO_0_Mode_GeneralPurpose);
 GPIO_setDirection(myGpio, GPIO_Number_0, GPIO_Direction_Output);

Actually, I found out that to turn the onboard LEDs we need to drive the signal low, and to turn them off the signal must be high.
For this reason, by default, all 4 leds are on (or at least this happened to me), so I specifically switched all them off before the loop for the blink.


    GPIO_setMode(myGpio, GPIO_Number_0, GPIO_0_Mode_GeneralPurpose);
  GPIO_setDirection(myGpio, GPIO_Number_0, GPIO_Direction_Output);
  GPIO_setMode(myGpio, GPIO_Number_1, GPIO_1_Mode_GeneralPurpose);
  GPIO_setDirection(myGpio, GPIO_Number_1, GPIO_Direction_Output);
  GPIO_setMode(myGpio, GPIO_Number_2, GPIO_2_Mode_GeneralPurpose);
  GPIO_setDirection(myGpio, GPIO_Number_2, GPIO_Direction_Output);
  GPIO_setMode(myGpio, GPIO_Number_3, GPIO_3_Mode_GeneralPurpose);
  GPIO_setDirection(myGpio, GPIO_Number_3, GPIO_Direction_Output);

  GPIO_setHigh(myGpio, GPIO_Number_0);
  GPIO_setHigh(myGpio, GPIO_Number_1);
  GPIO_setHigh(myGpio, GPIO_Number_2);
  GPIO_setHigh(myGpio, GPIO_Number_3);

Now, let's add a loop that turns the led on and off and le'ts cross our fingers :)

while(1)
{      
  GPIO_setLow(myGpio, GPIO_Number_0);
  DELAY_US(1000000);
  GPIO_setHgh(myGpio, GPIO_Number_0);
  DELAY_US(1000000);
}

Build, debug...
Does it work?
Not as expected for me, but I found out why.
What happened is that the delay was completely skipped.
By control-clicking it I found that function is actually defined in the DSP2802x_Examples.h file.
Something came back to my mind, while reading about the C2000 workshop I read something about memory segments and stuff that must be placed in the correct place... and I told to myself : "do I really need to care about that thing?".
Turns out that, yes, I have to.
To be honest, I didn't really get how the thing works yet (still reading), but the solution is to copy the functions from one area to another (or whatever is accomplished with the following lines).


#ifdef _FLASH
    memcpy(&RamfuncsRunStart, &RamfuncsLoadStart, (size_t)&RamfuncsLoadSize);
#endif

That, does the trick, but really, I will not attempt to explain it right now, I need to better understand it before.
Finally, this is my led blink source code :


/*
 * main.c
 */

#include "DSP28x_Project.h"     // DSP28x Headerfile

#include "f2802x_common/include/clk.h"
#include "f2802x_common/include/gpio.h"
#include "f2802x_common/include/pll.h"
#include "f2802x_common/include/wdog.h"


#ifdef _FLASH
    memcpy(&RamfuncsRunStart, &RamfuncsLoadStart, (size_t)&RamfuncsLoadSize);
#endif


void main()
{
 WDOG_Handle myWDog;
 myWDog = WDOG_init((void *)WDOG_BASE_ADDR, sizeof(WDOG_Obj));
 WDOG_disable(myWDog);

 CLK_Handle myClk;
 PLL_Handle myPll;
 myClk = CLK_init((void *)CLK_BASE_ADDR, sizeof(CLK_Obj));
 myPll = PLL_init((void *)PLL_BASE_ADDR, sizeof(PLL_Obj));

  CLK_setOscSrc(myClk, CLK_OscSrc_Internal);

  PLL_setup(myPll, PLL_Multiplier_12, PLL_DivideSelect_ClkIn_by_2);

  GPIO_Handle myGpio;
  myGpio = GPIO_init((void *)GPIO_BASE_ADDR, sizeof(GPIO_Obj));

  GPIO_setMode(myGpio, GPIO_Number_0, GPIO_0_Mode_GeneralPurpose);
  GPIO_setDirection(myGpio, GPIO_Number_0, GPIO_Direction_Output);
  GPIO_setMode(myGpio, GPIO_Number_1, GPIO_1_Mode_GeneralPurpose);
  GPIO_setDirection(myGpio, GPIO_Number_1, GPIO_Direction_Output);
  GPIO_setMode(myGpio, GPIO_Number_2, GPIO_2_Mode_GeneralPurpose);
  GPIO_setDirection(myGpio, GPIO_Number_2, GPIO_Direction_Output);
  GPIO_setMode(myGpio, GPIO_Number_3, GPIO_3_Mode_GeneralPurpose);
  GPIO_setDirection(myGpio, GPIO_Number_3, GPIO_Direction_Output);

  GPIO_setHigh(myGpio, GPIO_Number_0);
  GPIO_setHigh(myGpio, GPIO_Number_1);
  GPIO_setHigh(myGpio, GPIO_Number_2);
  GPIO_setHigh(myGpio, GPIO_Number_3);

  while(1)
  {
    GPIO_setLow(myGpio, GPIO_Number_0);
    DELAY_US(1000000);
    GPIO_setHigh(myGpio, GPIO_Number_0);
    DELAY_US(1000000);
  }

}

... and it blinks.

I also found a few issues with the linker not finding whatever it needed, I temporarily solved by cloning the demo project, removing the source and adding my new source.
Yup, I still have plenty of things to learn, that's he beauty of it, right?

[update : thanks to Trey@TI I found out what needs to be specified in the project properties when creating a new project from scratch (reporting it here just in case you encounter the same issue) :

1) in project -> properties -> CCS Build -> C2000 Compiler -> Include Options -> add dir : "C:\ti\controlSUITE\development_kits\C2000_LaunchPad"

2) in project -> properties -> CCS Build -> C2000 Linker -> File Search Path -> Include library : "C:\ti\controlSUITE\development_kits\C2000_LaunchPad\f2802x_common\lib\driverlib.lib"

]