Basics with DHT11 "Ack Low error

Other Hardware Sensors
1

I just bought the sensor DHT11 and trying to test it with the library code its in Arduino/libraries/DHTlib at master · RobTillaart/Arduino · GitHub
im using arduino 1.65 ver programmer AVRISP mkII
im totally new in arduino i just install the program and input the library to the places, and in using this ic too
wiring :
-left to 5v
-mid to data 5
-right to ground

//
//    FILE: dht11_test.ino
//  AUTHOR: Rob Tillaart
// VERSION: 0.1.01
// PURPOSE: DHT library test sketch for DHT11 && Arduino
//     URL:
//
// Released to the public domain
//

#include <dht.h>

dht DHT;

#define DHT11_PIN 5

void setup()
{
  Serial.begin(115200);
  Serial.println("DHT TEST PROGRAM ");
  Serial.print("LIBRARY VERSION: ");
  Serial.println(DHT_LIB_VERSION);
  Serial.println();
  Serial.println("Type,\tstatus,\tHumidity (%),\tTemperature (C)");
}

void loop()
{
  // READ DATA
  Serial.print("DHT11, \t");
  int chk = DHT.read11(DHT11_PIN);
  switch (chk)
  {
    case DHTLIB_OK:  
		Serial.print("OK,\t"); 
		break;
    case DHTLIB_ERROR_CHECKSUM: 
		Serial.print("Checksum error,\t"); 
		break;
    case DHTLIB_ERROR_TIMEOUT: 
		Serial.print("Time out error,\t"); 
		break;
    case DHTLIB_ERROR_CONNECT:
        Serial.print("Connect error,\t");
        break;
    case DHTLIB_ERROR_ACK_L:
        Serial.print("Ack Low error,\t");
        break;
    case DHTLIB_ERROR_ACK_H:
        Serial.print("Ack High error,\t");
        break;
    default: 
		Serial.print("Unknown error,\t"); 
		break;
  }
  // DISPLAY DATA
  Serial.print(DHT.humidity, 1);
  Serial.print(",\t");
  Serial.println(DHT.temperature, 1);

  delay(2000);
}
//
// END OF FILE

and heres the output

DHT TEST P 
LIBRARY VERSION: 0.1.20

Type,	status,	Humidity (%),	Temperature (C)
DHT11, 	Ack Low error,	0.0,	0.0
DHT TEST PROGRAM 
LIBRARY VERSION: 0.1.20

Type,	status,	Humidity (%),	Temperature (C)
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0

any idea for this error ?

12092475_10204907850398855_555708438_n.jpg
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12092221_10204907846958769_66516232_n.jpg
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2

Your code: #define DHT11_PIN 5

The picture shows the sensor output not connected to pin 5, but to pin 2.
Leo..

3

okay that was stupid i remembered changing the pinthough well what done is done. So after i tried to change it to pin 5 the same output came out

DHT TEST PROGRAM 
LIBRARY VERSION: 0.1.20

Type,	status,	Humidity (%),	Temperature (C)
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0
DHT11, 	Ack Low error,	0.0,	0.0

with the same program and the baud in the serial monitor is 115200
wiring as in the picture
red to 5v
green to 5 digital pin
black to ground
im using a 10k resistor too

test.jpg
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4

Your picture is a bit unclear, but is seems the left wire of the 10k resistor is connected to an empty strip.
Leo..

5

i connect the resistor to pin 1 and pin 2 of dht 11

6

Did you check. I see the left wire of the resistor clearly plugged into an unused strip.
Leo..

7

yeah, did i do it wrong ?

12081516_10204910911515381_410303462_n.jpg
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8

Much better picture.
Seems to be connected right.
Maybe Rob Tillaart (moderator here) can check if there is a problem with the code.
Leo..

9

ouw okay, i dunno wat else to do haha

10

Bump pleasehelp

11

Please try the DHT-stable version 0.1.13 as the 0.1.20 is a highly optimized version that can have some unwanted side effects as it is not verified on all boards.

Please post the output,
Rob

12

uhm it already work sorry for the trouble the breadboard i use seems to be broken because after i use different one it work

13

Good to hear it is solved.

14

Today i've encountered very similar issue with two DHT11 from different suppliers.

DHTLib v0.1.21 constantly reports DHTLIB_ERROR_CONNECT and sometimes DHTLIB_ERROR_ACK_L for both sensors.

DHTLib v0.1.13 constantly reports DHTLIB_ERROR_TIMEOUT only for one those sensors, but second works perfectly (without any errors)

DHT11.h v0.4.1 works like a charm with both sensors.

15

URL's
v0.4.1. - Arduino Playground - HomePage
DHTLib - Arduino/libraries at master · RobTillaart/Arduino · GitHub