dht11 with a 7 segment display displaying test pattern?

Other Hardware Sensors
1

so i got this neat 7 segment display module, and it works fine using SevSeg library, so i thought id add the dht11 sensor, eventually make a little weather station. so the dht11 works fine over serial, 7 segment display works fine for a counter, but i cant seem to send the dht to the 7seg. whats weird is i get the leds to blink either randomly, or in their test pattern, which i am thoroughly confused by.

#include <DHT.h>
#include <DHT_U.h>
#include <SevSeg.h>

SevSeg sevseg; //Instantiate a seven segment object

DHT dht(A0, DHT11);

  byte numDigits = 4;
  byte digitPins[] = {0,1,2,3};
  byte segmentPins[] = {4,5,6,7,8,9,10,11};
  bool resistorsOnSegments = false; // 'false' means resistors are on digit pins
  byte hardwareConfig = P_TRANSISTORS; // See README.md for options
  bool updateWithDelays = false; // Default 'false' is Recommended
  bool leadingZeros = true; // Use 'true' if you'd like to keep the leading zeros
  bool disableDecPoint = true; // Use 'true' if your decimal point doesn't exist or isn't connected
  


void setup() {
  
  
  sevseg.begin(hardwareConfig, numDigits, digitPins, segmentPins, resistorsOnSegments,
  updateWithDelays, leadingZeros, disableDecPoint);
  sevseg.setBrightness(90);

  dht.begin();
 
}

void loop() {


  sevseg.setNumber(8008);
  sevseg.refreshDisplay();
  delay(1000);
  sevseg.setNumber(880);
  sevseg.refreshDisplay();
  delay(1000);


  /*
  delay(1000);
  unsigned long h = dht.readHumidity();
  sevseg.setNumber(h);
  delay(100);
  sevseg.refreshDisplay();
  delay(1000);
  sevseg.setNumber(dht.readTemperature(true));
  delay(100);
  sevseg.refreshDisplay();
 */
}

the commented part of the loop has segments light up randomly, so i commented it and tried to get it to at least say something specfic. that cycles through each segment A-G, instead. i am confused because i would expect an error in this code to at least cycle between 2 things, not a full rotation. it still updates depending on how long a delay i set too. i am aware that usb communication uses pins 0 and 1, those are the left-most digits and are disconnected. 60 second countdown timer displays just fine, but i cant seem to manually set the display, im about to peel my face off with some of these libraries

2

I quote from the library documentation:

Your program must run the refreshDisplay() function repeatedly to display the number. Note that any delays introduced by other functions will produce undesirable effects on the display.

You should call it at least about 100 times a second to get a clear display. As you have several delay() calls in your code this doesn't happen.

3

you are correct, removing delays lets me set it manually. i still find it extremely bizarre that it displays the pattern like it does. i guess i need to rework it to use millis() instead then?

4

Correct.

5

for the sake of anyone who finds this through google or wherever, a basic loop() for what im doing looks like this:

  unsigned long oldtime = 0;
  unsigned long ntime;
  unsigned long refRate = 1000;
//note-above variables i actually have at the top with library inclusions, dont know if that matters in this case


ntime = millis();

    if (ntime - oldtime >= refRate){
       oldtime = ntime;
       sevseg.setNumber(dht.readTemperature(true));
    }
    
    sevseg.refreshDisplay();

above works as expected