Connecting 2 Grove devices to Stalker 3.0

Hi,

I'd like to solve this soon since I have to complete the data logging and ship it to South America to be installed on the projects we're working on in Honduras.

The DHT11 is still not working plugged into the D7/D8 port in the base Stalker 3.0 shield.
The DHTTYPE is DHT11, the DHTPIN is 7 the result is the same:

Code:

nan
0.00
32.00
Failed to read from DHT sensor!

What about this? Does the Stalker 3.0, which runs at 8Mhz need to have the threshold adjusted? I've already tried the following: 0 through 30 and the results are all over the map. No humidity reading at all and wildly incorrect temperature readings.

Code:

// Initialize DHT sensor for normal 16mhz Arduino
DHT dht(DHTPIN, DHTTYPE);
// NOTE: For working with a faster chip, like an Arduino Due or Teensy, you
// might need to increase the threshold for cycle counts considered a 1 or 0.
// You can do this by passing a 3rd parameter for this threshold.  It's a bit
// of fiddling to find the right value, but in general the faster the CPU the
// higher the value.  The default for a 16mhz AVR is a value of 6.  For an
// Arduino Due that runs at 84mhz a value of 30 works.
// Example to initialize DHT sensor for Arduino Due:
//DHT dht(DHTPIN, DHTTYPE, 30);

This is the exact testing code I'm using. I've tried the PHTPIN on A0, 7 and 8. I've tested with the DHTTYPE set to DHT11 and DHT22 (though I am using a DHT11) and oddly, the results are the same (see above).

I thought the idea with grove was near plus and play (or close). The barometer I'm using (plugged into the 12C port) works perfectly (mind you, it's different).

Interestingly enough I tested the DHT11 on the 12C port... it doesn't work there either. I've also tested 3 different DHT11 units on the stalker 3 base shield, none work and there are still no usable results.

Code:

// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, public domain

#include "DHT.h"

#define DHTPIN 7    // what pin we're connected to

// Uncomment whatever type you're using!
#define DHTTYPE DHT11   // DHT 11
//#define DHTTYPE DHT22   // DHT 22  (AM2302)
//#define DHTTYPE DHT21   // DHT 21 (AM2301)

// Connect pin 1 (on the left) of the sensor to +5V
// NOTE: If using a board with 3.3V logic like an Arduino Due connect pin 1
// to 3.3V instead of 5V!
// Connect pin 2 of the sensor to whatever your DHTPIN is
// Connect pin 4 (on the right) of the sensor to GROUND
// Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor

// Initialize DHT sensor for normal 16mhz Arduino
DHT dht(DHTPIN, DHTTYPE);
// NOTE: For working with a faster chip, like an Arduino Due or Teensy, you
// might need to increase the threshold for cycle counts considered a 1 or 0.
// You can do this by passing a 3rd parameter for this threshold.  It's a bit
// of fiddling to find the right value, but in general the faster the CPU the
// higher the value.  The default for a 16mhz AVR is a value of 6.  For an
// Arduino Due that runs at 84mhz a value of 30 works.
// Example to initialize DHT sensor for Arduino Due:
//DHT dht(DHTPIN, DHTTYPE, 30);

void setup() {
  Serial.begin(9600);
  Serial.println("DHTxx test!");

  dht.begin();
}

void loop() {
  // Wait a few seconds between measurements.
  delay(2000);

  // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  float h = dht.readHumidity();
  // Read temperature as Celsius
  float t = dht.readTemperature();
  // Read temperature as Fahrenheit
  float f = dht.readTemperature(true);
 
  // Check if any reads failed and exit early (to try again).
  //if (isnan(h) || isnan(t) || isnan(f)) {
    Serial.println(h);
    Serial.println(t);
    Serial.println(f);
    Serial.println("Failed to read from DHT sensor!");
    return;
  //}

  // Compute heat index
  // Must send in temp in Fahrenheit!
  float hi = dht.computeHeatIndex(f, h);

  Serial.print("Humidity: ");
  Serial.print(h);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(t);
  Serial.print(" *C ");
  Serial.print(f);
  Serial.print(" *F\t");
  Serial.print("Heat index: ");
  Serial.print(hi);
  Serial.println(" *F");
}

Statistics : Posted by byronjbignell • on Sat Jan 03, 2015 5:33 pm • Replies 8 • Views 372

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