Test the timing of indivisual ones and zeros on the DCC protocol.

DCC_Timing_tester_esp8266.ino

#include "ESP8266WiFi.h"
#include "WiFiClient.h"

const int baudrate = 250000;
const int dccpin = 0; //D3 on wemos board
int olddcc = 0;
unsigned long t = 0;
unsigned long lastchangeus = 0;
byte ones[16384];
byte zeros[16384];
unsigned  int ptr = 0;
unsigned long loops = 0;
unsigned long loopstime = 0;
void setup() {
  Serial.begin(baudrate);
  pinMode(dccpin, INPUT_PULLUP);
  Serial.println("Welcome to the DCC tester, set the serial to baud rate 2,000,000");
  Serial.println("first number is is low usecs, second is high usecs");
  //Serial.println(2000000);
  loopstime = millis();
  WiFi.mode( WIFI_OFF );
  WiFi.forceSleepBegin();
  //ESP.wdtDisable();
  delay(10);
}

void loop() { //an ESP loop has an overhead of 5us!
  unsigned long steppedmicros = micros(); //as loading millis takes nearly 5 usecs!
  for (int i = 0; i < 100; i++) {
    loops++;
    int newdcc = digitalRead(dccpin);

    if (newdcc != olddcc) {
      unsigned long newt = micros();
      lastchangeus = newt;
      steppedmicros = newt;
      if (newdcc == 0) {
        ones[ptr] = newt - t;
        ptr++;
      } else {
        zeros[ptr] = newt - t;
      }
      //Serial.print('.');
      t = newt;
    }
    olddcc = newdcc;
    if ((steppedmicros - lastchangeus > 2000000) || (ptr > 16000)) {
      lastchangeus = micros();
      steppedmicros = micros();
      Serial.print(steppedmicros);
      Serial.print(' ');
      Serial.print(lastchangeus);
      Serial.print(" Total number of samples:");
      Serial.println(ptr);
      for (unsigned int i = 0; i < ptr; i++) {
        Serial.print(zeros[i]);
        Serial.print('\t');
        Serial.println(ones[i]);
        yield();
      }
      ptr = 0;
      
      if (loops > 1000000) {
        Serial.print(loops);
        Serial.print(" loops done in ms ");
        Serial.println(millis() - loopstime);
        loopstime = millis();
        loops = 0;
      }
    }

  }
}