/**************************************************/

/*** File Name: 256.c ***/

/*** Product Name: SRC-256 ***/

/*** Description: 6 channel DMX controller ***/

/*** MCU: At89c2051(or At89c1051u) Xtal: 8MHz ***/

/*** Author: Hawk Wang, Date: 08/12 ***/

/*** Version: Rev 1.0 ***/

/**************************************************/

/*** IO assign map ***/

/*** P1 ---DAC data out ***/

/*** P3_0 ---NC ***/

/*** P3_1 ---Txd ***/

/*** P3_2 ---comparator out ***/

/*** P3_3 ---4051 a chanel ***/

/*** P3_4 ---4051 b chanel ***/

/*** P3_5 ---4051 c chanel ***/

/*** P3_7 ---573LE(not use) ***/

#pragma ROM(SMALL) OPTIMIZE (5,SIZE)

#include "AT892051.H"

//define crystal frequence

#define XTAL 8 //XTAL: 8MHz

//variable declare

unsigned char AdcDataList[7]; //0:master,1:channel1,2:channel2,etc.

//function declare

void Init(void);

unsigned char GetAdcValue(unsigned char ch_n); //ch_n range: 0~6(channel7 not use)

void DmxOut(void);

//main function

void main(void)

{

unsigned char adc_channel;

Init();

while(1) //runtime of while loop: 37ms(xtal=8mhz)

{

for(adc_channel=0;adc_channel<=6;adc_channel++)

{

AdcDataList[adc_channel] = GetAdcValue(adc_channel);

}

DmxOut();

}

}

/*** Initialize IO,UART ***/

void Init(void)

{

IE = 0x00; //disable all interrupt

P1 = 0xff;

P3 = 0xff;

TCON = 0x00;

#if XTAL == 8

PCON = 0x80; //SMOD=1

#else

PCON = 0x00; //SMOD=0

#endif

SCON = 0x88; //UART mode2,TB8=1,disable receive

}

/*** get adc value ***/

/*** ch_n=0: master ***/

/*** ch_n=1: ch1 ***/

/*** ........... ***/

/*** ch_n=6: ch6 ***/

unsigned char GetAdcValue(unsigned char ch_n)

{

unsigned char value;

P3 = (P3&0xc3)|(ch_n<<3)|0x04; //select ADC channel

P1 = 0xff;

for(value=0xff;(P3_2==1)&&(value>0); )

{

P1 = --value;

}

return (value);

}

void DmxOut(void)

{

unsigned char dimmer_number;

unsigned char delay_time;

TXD = 0; //sent reset,mark after reset

delay_time = 20; //delay (20*6+7)*1.5us>88us

while(delay_time--);//(delay_time*6+7)*12/XTAL

TXD = 1;

delay_time =2; //delay>8us

while(delay_time--);

SBUF = 0x00; //sent start code

while(!TI);

TI = 0;

for(dimmer_number=1;dimmer_number<=6;dimmer_number++)

{

SBUF = (unsigned char) (((unsigned int)(AdcDataList[dimmer_number]+1))*AdcDataList[0]>>8); //runtime=43*(12/XTAL)

while(!TI);

TI = 0;

}

}