74HC165-HSPI+Intrrupt.ino

/* 74HC165 ESP8266 ~ NodeMCU 1.0 (ESP-12E Module)
 * speed-test reading 18 shift (in) registers
 * 
 * adapted from article by João Alves
 * https://jpralves.net/post/2015/09/08/multiple-inputs-parallel-to-series.html
 * 
 * Pinos usados: 
     D0  (gpio16) - Load Pin (1) do 74HC165 
     D1  (gpio5)  - Interrupt Pin do Diodes
     D6  (hmiso)  - Q7 Pin (9) do 74HC165 
     D5  (hsclk)  - CLOCK Pin (2) do 74HC165 
 * Sketch que usa a comunicação SPI + interrumpir. 
*/ 

#include <SPI.h> 

const byte LATCH = D0;
const byte INTER = D1;
const byte chips = 18; // number of 74HC165 (8bit) chips used

static unsigned long lastMillis;
static unsigned long frameCount;
static unsigned int framesPerSecond;
const int seconds = 1;

// FIXME: finish interrupt support ...

void setup() {
 SPI.begin (); 
 SPI.beginTransaction(SPISettings(32000000, MSBFIRST, SPI_MODE3)); // 32MHz
 Serial.begin(230400); 
 pinMode (LATCH, OUTPUT); 
 digitalWrite (LATCH, HIGH); 
}

void loop() {
  unsigned long now = millis();
  frameCount ++; // Once around the moon ...
  
  byte Switch[chips];
  
  digitalWrite (LATCH, LOW); 
  digitalWrite (LATCH, HIGH); 

  for (byte i=0; i<chips; i++) { 
    Switch[i] = SPI.transfer(0); 
  }
    
  if (now - lastMillis >= seconds * 1000) {
    framesPerSecond = frameCount / seconds;
    
    for (byte i=0; i<8; i++) { 
      Serial.print((Switch[0] & (1<<i)) != 0 ? 0 : 1); 
    } 

    Serial.print(" "); 

    for (byte i=0; i<8; i++) { 
      Serial.print((Switch[1] & (1<<i)) != 0 ? 0 : 1); 
    } 
        
    Serial.print(" "); 
    Serial.print(framesPerSecond);
    Serial.println(" fps"); 

    frameCount = 0;
    lastMillis = now;
  }
}