用51单片机制作ps2接口的工业小键盘.doc

用51单片机制作ps2接口的工业小键盘经过我的验证，是完全可行的。#include #include #define uchar unsigned char#defineSEM_FULL 1#define SEM_EMPTY 0uchar bdata ps2char;uchar bdata keystatus;uchar bdata parity_buf;uchar bdata s_buf,r_buf;uchar data last_s;sbit date=P30;sbit clock=P32;sbit key0=P20;sbit key1=P21;sbit key2=P22;sbit key3=P23;sbit key4=P24;sbit key5=P25;sbit key6=P26;sbit key7=P27;sbit s_buf0=s_buf0;sbit r_buf7=r_buf7;sbit parity_buf0=parity_buf0;bit ps2_tx_sem=SEM_EMPTY;bit ps2_sendbyte(uchar c);void delayus(uchar us) while(-us);void delayms(uchar ms) uchar i; while(ms-) for(i=0;i120;i+);bit parity() bit PARITY=1;uchar i;for(i=0;i1;return PARITY; void ps2_tx_sem_take()ps2_tx_sem0:EA=0;if(ps2_tx_sem=SEM_FULL) EA=1; delayus(30);delayus(30); goto ps2_tx_sem0; ps2_tx_sem=SEM_FULL;EA=1;return;void ps2_tx_sem_give() EA=0; ps2_tx_sem=SEM_EMPTY; EA=1; return;void ps2_clk_check()ps_tx_sem:EA=0;if(clock=0)/ if PS2_CLK low, wait for 50us EA=1; delayus(30); goto ps_tx_sem; EA=1;return;void ps2_send(uchar dat) ps2_tx_sem_take(); ps2_clk_check(); if(date=1) ps2_sendbyte(dat); ps2_tx_sem_give();uchar ps2_recbyte()/ Return receice data，Error return 0uchar i;bit PARITY;r_buf=0;while(!clock);/ Wait KBCLK Highdelayus(10); if(date) / KBDATA shoud be low，mean received start bit ps2_send(0xfe); / if KBDATA is High, return and send error status date(0xfe) return 0;delayus(30);clock=0; / Device control the KBCLK signalfor(i=0;i1;delayus(10);clock=0;delayus(30);clock=1;delayus(10);if(!clock) return 0; / if KBCLK pull down, mean Host cancelled this sending PARITY=date; / Receive odd parity bitdelayus(10);clock=0;delayus(30);clock=1;delayus(10);/ Receive Stop bit, should be highif(!date) / Otherwise,send error status date(0xfe) ps2_send(0xfe); return 0;date=0;/ Send ACK bit, mean have receive data donedelayus(10);clock=0;delayus(30);clock=1; / Set KBCLK and KBDATA highdelayus(10);date=1;delayus(10); parity_buf=r_buf;if(PARITY=parity()/ Check Odd parity return r_buf;else ps2_send(0xfe); return 0;delayus(30);bit ps2_sendbyte(uchar c)/ Success return 1，Fail return 0 uchar i; bit PARITY;clock=1;if(!clock)/ Host prevent Keyboard sending data return 0; parity_buf=c;PARITY=parity();/ Calculate value about sending data odd paritylast_s=c; / Save last sending datas_buf=c; if(!clock)/ Host prevent Keyboard sending data return 0;if(!date)/ Host prepared sending command data to keyboard return 0; date=0; / Falling edge of KBCLK send data, start bit 0delayus(10); clock=0; for(i=0;i1; delayus(10); clock=0; delayus(10); clock=1;delayus(10); if(!clock) / if KBCLK is low，mean Hos prevent Keyboard sending data return 0; date=PARITY;/ Sending odd parity bitdelayus(10); clock=0;delayus(10); clock=1;delayus(10); date=1; / Sending stop bitdelayus(10); clock=0;delayus(30); clock=1;delayus(30); delayus(10); return 1;bit bat() if(P2!=0xff) return 1; else return 0; void re_send ( ) ps2_send(last_s);void reset() clock=1; date=1; while(!clock|!date);/ Wait KBCLK and KBDATA high if(bat()ps2_send(0xfc);/ Self-Check failed else ps2_send(0xaa);/ Self-Check successedbit Check_command ( )/ Keyboard receive host command，return 1 clock=1; date=1; if(!clock&!date)return 1; elsereturn 0;void receive_process()uchar command;if(!Check_command() return;command=ps2_recbyte();if(!command) return;switch(command) case 0xff: / reset command ps2_send(0xfa); reset(); break; case 0xfe: / re-send command ps2_send(0xfa); re_send(); break; case 0xf3:/ Set Typematic Rate/Delay ps2_send (0xfa); break; case 0xf2:/ Read ID ps2_send(0xfa); ps2_send(0xAB); ps2_send(0x83); break; case 0xee:/ respond command ps2_send(0xee); case 0x00: ps2_send(0xfe); break; default: ps2_send(0xfa);/ other command, just send a response of 0xFA break; void main()P2=0xff;if(bat() ps2_send(0xfc);else ps2_send(0xaa); while(1) if(Check_command() receive_process(); key4=0; while(!key4) if(!key0)delayms(5); if(!key0) ps2_sendbyte(0x1C); delayms(5); ps2_sendbyte(0xF0); delayms(1); ps2_sendbyte(0X1C); while(!key0); else if(!key1)delayms(5);if(!key1) ps2_sendbyte(0x32); delayms(5); ps2_sendbyte(0xF0); delayms(1); ps2_sendbyte(0X32); while(!key1); else if(!key2)delayms(5);if(!key2) ps2_sendbyte(0x21); delayms(5); ps2_sendbyte(0xF0); delayms(1); ps2_sendbyte(0X21); while(!key2); else if(!key3)delayms(5);if(!key3) ps2_sendbyte(0x23); delayms(5); ps2_sendbyte(0xF0); delayms(1); ps2_sendbyte(0X23); while(!key3); else key4=1; key5=0; while(!key5) if(!key0)delayms(5); if(!key0) ps2_sendbyte(0x24); delayms(5); ps2_sendbyte(0xF0); delayms(1); ps2_sendbyte(0X24); while(!key0); else if(!key1)delayms(5);if(!key1) ps2_sendbyte(0x2B); delayms(5); ps2_sendbyte(0xF0); delayms(1); ps2_sendbyte(0X2B); while(!key1); else if(!key2)delayms(5);if(!key2) ps2_sendbyte(0x34); delayms(5); ps2_sendbyte(0xF0); delayms(1); ps2_sendbyte(0X34); while(!key2); else if(!key3)delayms(5);if(!key3) ps2_sendbyte(0x33); delayms(5); ps2_sendbyte(0xF0); delayms(1); ps2_sendbyte(0X33); while(!key3); else key5=1; key6=0; while(!key6) if(!key0)delayms(5); if(!key0) ps2_sendbyte(0x43); delayms(5); ps2_sendbyte(0xF0); delayms(1); ps2_sendbyte(0X43); while(!key0); else if(!key1)delayms(5);if(!key1) ps2_sendbyte(0x3B); delayms(5); ps2_sendbyte(0xF0); delayms(1); ps2_sendbyte(0X3B); while(!key1); else if(!key2)delayms(5);if(!key2) ps2_sendbyte(0x42); delayms(5); ps2_sendbyte(0xF0); delayms(1); ps2_sendbyte(0X42); while(!key2); else if(!key3)delayms(5);if(!key3) ps2_sendbyte(0x4B); delayms(5); ps2_sendbyte(0xF0); delayms(1); ps2_