IBM H8 user manual Key’s and LED’s, LEDSPEEDINIT4

HTEB1

User manual

3.1 Key’s and LED’s

The first demo program shows the usage of LEDs and keys on HTEB1. For time-controlling we use TIMER_A as an periodic interval timer. The interrupt service routine (isr) is checking the state of the keys, actualising the LED port and reading out the AD1-channel to determine the running light speed. If you want to do some experiments, first check out to find if other LED pattern maybe in form of a table read out or calculate them by functions developed by yourself. If speed control should be changed, first change the calculation of the A/D-conversion value to timer ticks.

/*------------------------------------------------------------------

**KeysLEDs.c contains some sample code for using LEDs and Key's

**on TinyEvalBoard

**in addition Timer_A is used for timer tick with irq

**-----------------------------------------------------------------*/

#include "mydefs.h"		// for all nec. includes
/* defines */
#define KEY_1	0x10
#define KEY_2	0x20
#define KEY_3	0x04
#define KEY_4	0x02

#define KEY_ALL		(KEY_1KEY_2KEY_3KEY_4)
#define KEY_RELEASED		0x40
#define	KEY_PROCESSED	0x80
#define	LED_SPEED_INIT4		// = 4/32 = 1/8s = 125ms

/* variables */ u8 KeyCode=0;

u8 LED_Out, LED_Dir, LED_Run, LED_Speed;

/* functions */ void KeyCheck(void)

{

if ((PDR1 & KEY_ALL) != KEY_ALL) // is any key pressed ?

{

if (!(PDR1 & KEY_1)) KeyCode = KEY_1;

else if (!(PDR1 & KEY_4)) KeyCode = KEY_4; else if (!(PDR1 & KEY_3)) KeyCode = KEY_3; else if (!(PDR1 & KEY_2)) KeyCode = KEY_2;

}
else
{
KeyCode = KEY_RELEASED;	// no, mark key_released
}
}
void RunningLightUpdate(void)	// check for keypresse
{	// and update LEDs
u8 dummy;
u16 adval;

if (!(KeyCode & KEY_RELEASED))

{

if ((KeyCode & KEY_1)==KEY_1) LED_Dir = 1;

else if ((KeyCode & KEY_4)==KEY_4) LED_Dir = 0; else if ((KeyCode & KEY_2)==KEY_2) LED_Run = 0; else if ((KeyCode & KEY_3)==KEY_3) LED_Run = 1; KeyCode = KEY_RELEASED;

Issue 0.2 Page 33 07/2002