我已經完成了這個在C和python上的pi和arduino上。根據我的經驗，@woodrow douglas說您需要捕獲循環中的位或使用中斷（更好），並使用每次接收到一點時增加的超時，然後在確定擁有所有位後將其打印出來（時間到）。
這是我如何使用中斷在arduino上完成的。
void zero(){
bit_count ++;
bit_holder = (bit_holder << 1) + 0; //shift left one and add a 0
timeout = t;
}
void one(){
bit_count ++;
bit_holder = (bit_holder << 1) + 1; //shift left one and add a 1
timeout = t;
}
void loop() {
timeout --;
if (timeout == 0 && bit_count > 0){
lcd.clear();
lcd.print("Dec:");
lcd.print(bit_holder);
lcd.setCursor(0,1);
lcd.print("Hex:");
lcd.print(String(bit_holder,HEX));
Serial.print("bit count= ");
Serial.println(bit_count);
Serial.print("bits= ");
Serial.println(bit_holder,BIN);
oldbit = bit_holder; //store previous this value as previous
bit_count = 0; //reset bit count
bit_holder = 0; //reset badge number
}
}
我從來沒有用C皮上的任何問題，但我沒有得到使用Python，因爲它是不是真正的時間問題。它能夠在Python中工作的唯一方式是使用中斷，並且我管理的讀取率也降到了1比200，但從未完全刪除它。
我最後做的是使用一些C來收集位，然後調用我的Python腳本的位進行處理。
如果你有興趣，這是C代碼我使用：
#include <wiringPi.h>
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <time.h>
int r1data0 = 6; //pin 22
int r1data1 = 7; // Pin 7
// green goes to same as relay
int r1beep = 0; //pin 11
int r2data0 = 10; /* P1-24 */
int r2data1 = 11; /* P1-26 */
//green goes to same as relay
int r2beep = 0;
int i1 = 0;
int i2 = 0;
//generic variables
int t = 5;
int blank; //blank variable to reset bits
int rel1time = 0;
int rel2time = 0;
int rel1 = 5;
int previoust;
//reader 1variables
int r1bits; // Collected bits storage area
int r1bit_count = 0; //to measure the size of bits
int oldr1bit_count = 0; //somewhere to store bitcount to send to python
int r1timeout; //timout to return correct value
char r1command[40];
int r1ret;
//reader 2 variables
int r2bits; // Collected bits storage area
int r2bit_count = 0; //to measure the size of bits
int oldr2bit_count = 0;
int r2timeout; //timout to return correct value
char r2command[40];
pthread_t threads;
void access_denied(int red){
int pin;
if(red = 1){pin = r1beep;}
if(red = 2){pin = r2beep;}
pinMode(pin, OUTPUT);
digitalWrite(pin, LOW);
delay(300);;
digitalWrite(pin, HIGH);
delay(200);
digitalWrite(pin, LOW);
delay(300);
digitalWrite(pin, HIGH);
delay(200);
digitalWrite(pin, LOW);
delay(300);
digitalWrite(pin, HIGH);
}
void *r1python_thread(void *val){
sprintf(r1command,"python access.py r1 %X %X", oldr1bit_count, val); //build python command
FILE* file = popen(r1command, "r"); //execute command using popen
char buffer[5];
fscanf(file, "%100s", buffer); //read command output
pclose(file);
//printf("buffer is : %s\n", buffer);
rel1time = atoi(buffer); //convert returned string to int
if(rel1time == 0){access_denied(1);}
pthread_exit(NULL);
}
void *r2python_thread(void *val){
sprintf(r2command,"python access.py r2 %X",val); //build python command
FILE* file = popen(r2command, "r"); //execute command using popen
char buffer[5];
fscanf(file, "%100s", buffer); //read command output
pclose(file);
//printf("buffer is : %s\n", buffer);
rel2time = atoi(buffer); //convert returned string to int
pthread_exit(NULL);
}
//reader 1 bit functions
void onebit0(){ //adds a 0
r1bit_count ++; //increase bit count
r1bits = (r1bits << 1) + 0;
r1timeout = t; //reset timeout
}
void onebit1(){ //adds a 1
r1bit_count ++;
r1bits = (r1bits << 1) + 1;
r1timeout = t;
}
//reader 2 bit functions
void twobit0(){ //adds a 0
r2bit_count ++; //increase bit count
r2bits = (r2bits << 1) + 0;
r2timeout = t; //reset timeout
}
void twobit1(){ //adds a 1
r2bit_count ++;
r2bits = (r2bits << 1) + 1;
r2timeout = t;
}
int main(){
wiringPiSetup(); //initialise wiringPi
pinMode (r1data0, INPUT); // set reader 1 data0 as input
pinMode (r1data1, INPUT); // set reader 1 data1 as input
pinMode (r2data0, INPUT); // set reader 2 data0 as input
pinMode (r2data1, INPUT); // set reader 2 data1 as input
//reader 1
wiringPiISR(r1data0, INT_EDGE_FALLING, onebit0); // set interrupt on data 0 if it falls call bit0 function
wiringPiISR(r1data1, INT_EDGE_FALLING, onebit1); // set interrupt on data 1 if it falls call bit1 function
//reader 2
wiringPiISR(r2data0, INT_EDGE_FALLING, twobit0); // set interrupt on data 0 if it falls call bit0 function
wiringPiISR(r2data1, INT_EDGE_FALLING, twobit1); // set interrupt on data 1 if it falls call bit1 function
while (1){ //loop
if (r1bit_count > 0){ //if bits is not empty
r1timeout--; // reduce timeout by 1
if(r1timeout == 0){ //and it has timed out ie no more bits coming
//printf("%X\n",r1bits);
pthread_create(&threads, NULL, r1python_thread,(void *) r1bits); //start new thread for python program
oldr1bit_count = r1bit_count;
r1bit_count = 0; //reset bit count
r1bits = blank; //clear bits cariable
r1timeout = t; //reset timeout
}
}
if (r2bit_count > 0){ //if bits is not empty
r2timeout--; // reduce timeout by 1
if(r2timeout == 0){ //and it has timed out ie no more bits coming
pthread_create(&threads, NULL, r2python_thread,(void *) r2bits); //start new thread for python program
r2bit_count = 0; //reset bit count
r2bits = blank; //clear bits cariable
r2timeout = t; //reset timeout
}
}
if (rel1time > 0){
pinMode(rel1, OUTPUT);
int diff = time(NULL) - previoust;
if(diff >= 1){
previoust = time(NULL);
rel1time--;
}
}
else{
pinMode(rel1, INPUT);
previoust = time(NULL);
}
delay(1);
}
return 0;
}
我現在已經改變了我的代碼爲Java。它正在做同樣的事情 –
同樣的問題 - 我建議在你的while循環中添加一個超時（或其他一些同步機制）。這個代碼看起來幾乎是不確定的。 –