MiniMexleIO - Revision history

Balogh at 09:53, 5 November 2008

2008-11-05T09:53:50Z

Balogh at 09:32, 5 November 2008

2008-11-05T09:32:37Z

Balogh at 09:32, 5 November 2008

2008-11-05T09:32:16Z

Balogh at 09:32, 5 November 2008

2008-11-05T09:32:04Z

Balogh at 09:31, 5 November 2008

2008-11-05T09:31:15Z

Balogh at 09:30, 5 November 2008

2008-11-05T09:30:01Z

Balogh at 09:23, 5 November 2008

2008-11-05T09:23:45Z

Balogh at 09:16, 5 November 2008

2008-11-05T09:16:34Z

Balogh at 09:13, 5 November 2008

2008-11-05T09:13:05Z

Balogh at 11:52, 28 January 2008

2008-01-28T11:52:54Z

New page

The usual "Hello, World!" program in the area of the single chip microcontrollers is
to connect a pushbutton and LED and to control them.

We already have the pushbutton and the LED on the MiniMexle board, so here is an excerpt
from the whole schematics

[[Image:Example.jpg]]

And here is a short C-code for controlling them:

<source lang="c">
#include <avr\io.h>

int main()
{
while (1) {

if (PORTA&&0x0F) then
PORTD = 0x01;
else
PORTD = 0x01;

}

}
</source>

Task:

The task is to control the on and off state of the LED with a
single button. First press of the button will set LED on, second
press off. Hint: You will need a memory to store the actual LED
state to change it.

@@ Line 11: / Line 11: @@
 <source lang="c">
-#include <avr\io.h>
+/* ************************************************************************** */
 int main()
@@ Line 18: / Line 33: @@
 /* ***************** Initialization ************************ */
 /* Port settings for LED *********************************** */
       DDRB = 0b00000100;     // bin: 0000 0100  1 = out, 0 = in
      PORTB = 0xFF;           // bin: 1111 1111  1 = LED off
 /* Port settings for Switch ******************************** */
       DDRC = 0b00000000;     // bin: 0000 0000  1 = out, 0 = in
      PORTC = 0xFF;           // bin: 1111 1111  1 = pull-up active
-   while (1) {
+/* ***************** Main Endless Loop ********************** */
-−
-   if (PINC & 0b00000001) then
-      PORTB = 0x04;
+   while (1) {              // toto rob stale dokola
    else
       PORTB = 0x00;
+   }
 </source>

@@ Line 6: / Line 6: @@
 also active low (i.e. LED lights when port is logic 0).
-[[Image:MiniMexleIO.png|center|thumb|200px|Connection of the LED and pushbutton on the MiniMEXLE board.]]
+[[Image:MiniMexleIO.png|center|thumb|350px|Connection of the LED and pushbutton on the MiniMEXLE board.]]
 And here is a short C-code for controlling them:

@@ Line 32: / Line 32: @@
    if (PINC & 0b00000001) then
-      PORTD = 0x04;
+      PORTB = 0x04;
    else
-      PORTD = 0x00;
+      PORTB = 0x00;
+   }

@@ Line 32: / Line 32: @@
    if (PINC & 0b00000001) then
-      PORTD = 0x01;
+      PORTD = 0x04;
    else
-      PORTD = 0x01;
+      PORTD = 0x00;
+   }

@@ Line 14: / Line 14: @@
 int main()
 /* ***************** Initialization ************************ */
@@ Line 25: / Line 26: @@
      PORTC = 0xFF;           // bin: 1111 1111  1 = pull-up active
+/* ***************** Endless loop ************************* */
    while (1) {
    if (PINC & 0b00000001) then
       PORTD = 0x01;

@@ Line 2: / Line 2: @@
 to connect a pushbutton and LED and to control them.
-We already have the pushbutton and the LED on the MiniMexle board, so here is an excerpt
+We already have the pushbutton and the LED on the MiniMexle board - the pushbutton
-from the whole schematics
+is connected to the pin PC0 and is active low, the LED is connected to PB2 and is
-[[Image:MiniMexleIO.png]]
+[[Image:MiniMexleIO.png|center|thumb|200px|Connection of the LED and pushbutton on the MiniMEXLE board.]]
 And here is a short C-code for controlling them:
@@ Line 18: / Line 19: @@
 /* Port settings for LED *********************************** */
       DDRB = 0b00000100;     // bin: 0000 0100  1 = out, 0 = in
-     PORTB = 0xFF;           // bin: 1111 1111  1 = LED zhasni
+     PORTB = 0xFF;           // bin: 1111 1111  1 = LED off
 /* Port settings for Switch ******************************** */
-      DDRB = 0b00000100;     // bin: 0000 0100  1 = out, 0 = in
+      DDRC = 0b00000000;     // bin: 0000 0000  1 = out, 0 = in
-     PORTB = 0xFF;           // bin: 1111 1111  1 = LED zhasni
+     PORTC = 0xFF;           // bin: 1111 1111  1 = pull-up active
+{