ESP8266 Community Forum

Posted: **Sat Dec 05, 2020 11:26 am**

Hey,

I'm a bit desperate, because I tried to build a NodeMCU powered WiFi-Clock using a 4 digit seven segment display. As shown in the code block my programming skills are very poor.
Flashed on the ESP8266 the code just shows 3 digits and the forth digit is dark. Not every number is displayed correctly, BUT I checked the wiring (including resistors) merely a thousand times.

I just need a helping hand, giving me advice to make this display work correctly. Would be awesome!

Code: Select all

#include <ESP8266WiFi.h>
#include <NTPClient.h>
#include <WiFiUdp.h>


// ESP8266 Pins
int aPin = 14;  //         A
int bPin = 16;  //    ________
int cPin = 1;  //    |        |
int dPin = 13;  // F |        |  B
int ePin = 15;  //   |   G    |
int fPin = 0;  //    |________|
int gPin = 10;  //   |        |
int GND1 = 2; //     |        |
int GND2 = 4; //   E |        |   C
int GND3 = 5; //     |________|
int GND4 = 3; //       
int dPnt = 12;//         D       O dPnt

int DTime = 1; //delay für Itterationen, 16ms default, 4 ms jetzt


// Netzwerk-Credentials
const char *ssid     = "ssid";
const char *password = "password";

// NTP Client 
WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP, "pool.ntp.org");

void setup()
{
  pinMode(aPin, OUTPUT);
  pinMode(bPin, OUTPUT);
  pinMode(cPin, OUTPUT);
  pinMode(dPin, OUTPUT);
  pinMode(ePin, OUTPUT); 
  pinMode(fPin, OUTPUT);
  pinMode(gPin, OUTPUT);
  pinMode(GND1, OUTPUT);
  pinMode(GND2, OUTPUT);
  pinMode(GND3, OUTPUT);
  pinMode(GND4, OUTPUT);
  pinMode(dPnt, OUTPUT);
  
  // Serial Monitor
  Serial.begin(115200);
  
  // Connect to Wi-Fi
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

// NTPClient initialisieren
  timeClient.begin();
  timeClient.setTimeOffset(3600);
}


void loop()
{
  
  // alle digits ausschalten
  digitalWrite( GND1, HIGH);
  digitalWrite( GND2, HIGH);
  digitalWrite( GND3, HIGH);
  digitalWrite( GND4, HIGH);

 
  timeClient.update();

  int currentHour = timeClient.getHours();
  int digi1;
  digi1 = currentHour/10;
  
  int digi2;
  digi2 = currentHour%10;
    
  int currentMinute = timeClient.getMinutes();
  int digi3;
  digi3 = currentMinute/10;
  
  int digi4;
  digi4 = currentMinute%10;
  
  digitalWrite( GND4, LOW);    //digit 4
  pickNumber(digi4);
  delay(DTime);
  digitalWrite( GND4, HIGH);
  
  digitalWrite( GND3, LOW);    //digit 3
  pickNumber(digi3);
  delay(DTime);
  digitalWrite( GND3, HIGH);
 
  digitalWrite( GND2, LOW);   //digit 2
  pickNumber(digi2); 
  digitalWrite(dPnt, HIGH); //Dezimalpunkt
  delay(DTime);
  digitalWrite( GND2, HIGH);
  digitalWrite(dPnt, LOW);
 
  digitalWrite( GND1, LOW);   //digit 1
  pickNumber(digi1);
  delay(DTime);
  digitalWrite( GND1, HIGH);
}
 
void pickNumber(int x){
   switch(x){
     case 1: one(); break;
     case 2: two(); break;
     case 3: three(); break;
     case 4: four(); break;
     case 5: five(); break;
     case 6: six(); break;
     case 7: seven(); break;
     case 8: eight(); break;
     case 9: nine(); break;
     default: zero(); break;
   }
}

void clearLEDs()
{  
  digitalWrite(  aPin, LOW); // A
  digitalWrite(  bPin, LOW); // B
  digitalWrite(  cPin, LOW); // C
  digitalWrite(  dPin, LOW); // D
  digitalWrite(  ePin, LOW); // E
  digitalWrite(  fPin, LOW); // F
  digitalWrite(  gPin, LOW); // G
  digitalWrite(  dPnt, LOW); // Dezimalpunkt
}

void one()
{
  digitalWrite( aPin, LOW);
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH);
  digitalWrite( dPin, LOW);
  digitalWrite( ePin, LOW);
  digitalWrite( fPin, LOW);
  digitalWrite( gPin, LOW);
}

void two()
{
  digitalWrite( aPin, HIGH);
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, LOW);
  digitalWrite( dPin, HIGH);
  digitalWrite( ePin, HIGH);
  digitalWrite( fPin, LOW);
  digitalWrite( gPin, HIGH);
}

void three()
{
  digitalWrite( aPin, HIGH);
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH);
  digitalWrite( dPin, HIGH);
  digitalWrite( ePin, LOW);
  digitalWrite( fPin, LOW);
  digitalWrite( gPin, HIGH);
}

void four()
{
  digitalWrite( aPin, LOW);
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH);
  digitalWrite( dPin, LOW);
  digitalWrite( ePin, LOW);
  digitalWrite( fPin, HIGH);
  digitalWrite( gPin, HIGH);
}

void five()
{
  digitalWrite( aPin, HIGH);
  digitalWrite( bPin, LOW);
  digitalWrite( cPin, HIGH);
  digitalWrite( dPin, HIGH);
  digitalWrite( ePin, LOW);
  digitalWrite( fPin, HIGH);
  digitalWrite( gPin, HIGH);
}

void six()
{
  digitalWrite( aPin, HIGH);
  digitalWrite( bPin, LOW);
  digitalWrite( cPin, HIGH);
  digitalWrite( dPin, HIGH);
  digitalWrite( ePin, HIGH);
  digitalWrite( fPin, HIGH);
  digitalWrite( gPin, HIGH);
}

void seven()
{
  digitalWrite( aPin, HIGH);
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH);
  digitalWrite( dPin, LOW);
  digitalWrite( ePin, LOW);
  digitalWrite( fPin, LOW);
  digitalWrite( gPin, LOW);
}

void eight()
{
  digitalWrite( aPin, HIGH);
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH);
  digitalWrite( dPin, HIGH);
  digitalWrite( ePin, HIGH);
  digitalWrite( fPin, HIGH);
  digitalWrite( gPin, HIGH);
}

void nine()
{
  digitalWrite( aPin, HIGH);
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH);
  digitalWrite( dPin, HIGH);
  digitalWrite( ePin, LOW);
  digitalWrite( fPin, HIGH);
  digitalWrite( gPin, HIGH);
}

void zero()
{
  digitalWrite( aPin, HIGH);
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH);
  digitalWrite( dPin, HIGH);
  digitalWrite( ePin, HIGH);
  digitalWrite( fPin, HIGH);
  digitalWrite( gPin, LOW);
}

Posted: **Tue Dec 08, 2020 8:17 am**

I hope you're either using LCD 7 segment displays or are buffering the I/O ports with transistors: the GPIO's of an ESP can only source around 12mA and a single (red) LED segment can easily draw 20mA (it may work in the beginning, but might/will fail when used for a prolonged period of time).

Then your current problem (having had a quick glance at it):

GPIO1 and GPIO3 are used for serial, so you can't use serial at the same time (remove the "Serial.XXX" lines)
GPIO10 is used by the flash memory, you can't use that one

For ease of programming and hardware (saving GPIO's), you might want to consider using a shift register instead. :idea:

Posted: **Tue Dec 08, 2020 12:52 pm**

This won't help if you are fixed on a particular display but given a choice one can use a 4 digit display like a TM1637 which is controlled by I2C and needs just 2 GPIO.

Posted: **Sat Dec 12, 2020 1:26 pm**

QuickFix wrote:I hope you're either using LCD 7 segment displays or are buffering the I/O ports with transistors: the GPIO's of an ESP can only source around 12mA and a single (red) LED segment can easily draw 20mA (it may work in the beginning, but might/will fail when used for a prolonged period of time).

Absolutely true, but the GPIOs can sink around 20mA continuously according to a post at Espressif's BBS.

Post your schematic, oxymoron.

ESP8266 Community Forum

4 digit 7 segment display clock, help appreciated

4 digit 7 segment display clock, help appreciated

Re: 4 digit 7 segment display clock, help appreciated

Re: 4 digit 7 segment display clock, help appreciated

Re: 4 digit 7 segment display clock, help appreciated