8266 V-pin Cmd error/Login timeout

Arduino Model? (example: Arduino Uno)

Adafruit HUZZAH ESP8266 breakout

Arduino Ethernet / WiFi Shield? (example: Ethernet Shield W5100)

Adafruit HUZZAH ESP8266 breakout

Please describe the bug / issue. Attaching any relevant screenshots would be very helpful!

Rather constant Cmd errror/Login timeout that results in all the V-pins not being polled and written before the next time out. Resulting in higher numbered Vpins never being successfully reported to the server.

I’m sure the problem is with my code, but if it could be a timeout rule that can be extended that might be nice.

The code-

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

#include "DHT.h"
#define CAYENNE_DEBUG         // Cayenne Code Uncomment to show debug messages
#define DHTPIN 4              // what digital pin we're connected to
#define CAYENNE_PRINT Serial  // Cayenne Code Comment this out to disable prints and save space
// #include <CayenneEthernet.h>  // Cayenne Code Change this to use a different communication device. See Communications examples.
#include <CayenneWiFi.h>

// Cayenne authentication token. This should be obtained from the Cayenne Dashboard.
char token[] = "your token";
// Your network name and password.
char ssid[] = "your ssid";
char password[] = "your password";

// Uncomment whatever type you're using!
#define DHTTYPE DHT11   // DHT 11
//#define DHTTYPE DHT22   // DHT 22  (AM2302), AM2321
//#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.
// Note that older versions of this library took an optional third parameter to
// tweak the timings for faster processors.  This parameter is no longer needed
// as the current DHT reading algorithm adjusts itself to work on faster procs.

void setup() {
  pinMode(4, INPUT);
  Serial.println("DHTxx test!");
  Cayenne.begin(token, ssid, password);

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

  // 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 (the default)
  float t = dht.readTemperature();
  // Read temperature as Fahrenheit (isFahrenheit = true)
  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("Failed to read from DHT sensor!");

  // Compute heat index in Fahrenheit (the default)
  float hif = dht.computeHeatIndex(f, h);
  // Compute heat index in Celsius (isFahreheit = false)
  float hic = dht.computeHeatIndex(t, h, false);

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


// These functions are called when the Cayenne widget requests data for the Virtual Pin.
  Cayenne.virtualWrite(V0, dht.readTemperature(true));

  Cayenne.virtualWrite(V1, dht.readHumidity());

  Cayenne.virtualWrite(V2, dht.readTemperature());

  Cayenne.virtualWrite(V3, dht.readHumidity());

  Cayenne.virtualWrite(V4, dht.readTemperature(true));

Note the sporadic placement of the data points in the below graphs. Vpins 3 and 4.


@Ian was saying that setting pinmode is a no-no. Do you need to explicitly set it?

I don’t think this is your problem though. You’ve got a 1.5 second delay before returning to the Cayenne.Run process.

I recommend you strip out the delay and measurements and prints in the main loop, and see what you get with the virtual requests.


After seeing your code I thought I remembered from my previous days with Ardiuno that pinMode was required. Keep in mind I’m old and am suffering from CRS (can’t remember s***).

A 2 second delay is recommended for the DHT 11 because it is like me, old and slow. My plan was to scrub all the excess crap out of the code and give it a go. I have already played with the timing going from 1 second to 10 seconds and I seem to have the best success with the 1.5 seconds.

As always, thanks for your insight!


I get that, but understand that the Cayenne.Run isn’t getting serviced while it is waiting. Better to use a counter, and only do the read once the counter has counted out the equivalent of 2 seconds.

You will know this though, if you just comment out your code in the main loop and see if the timeout error goes away.



A couple additions/corrections to my OP.

The photo of the dashboard is the wrong board, should have been the 8266 not the Arduino. Here is the proper photo, not much different, but more accurate.

It is also important to note that I made changes to the CayenneWiFi.h as outlined by Adam below.

Sorry for the omissions,


You can try to revert those changes to see what happens

Stripping code now…

Not being a code guy I’m sure I’m going to break some stuff.

Not really stripping, rem-ing out, that should give you an idea of how old I am.


Still seeing similar activity. This one shows just Cmd error no Login timeout I wonder if there is a difference?

[601709] >msg 20,7,4
[601709] <msg 20,7,12
[606710] Cmd error
[608485] Connecting to arduino.mydevices.com:8442
[608688] <msg 2,1,10
[610542] >msg 0,1,200
[610542] Ready (ping: 1774ms).
[610542] <msg 17,24,71
<ver1.0.0h-beat10buff-in256devESP8266buildJun 27 2016 18:56:31
[612143] >msg 0,24,200
[613918] >msg 20,1,10
[615419] >msg 20,2,10
[617194] >msg 20,3,10
[618694] >msg 20,4,10
[620469] >msg 20,5,10
[621970] >msg 20,6,4
[621970] <msg 20,6,11
[626971] Cmd error
[628746] Connecting to arduino.mydevices.com:8442
[628971] <msg 2,1,10
[630894] >msg 0,1,200
[630894] Ready (ping: 1774ms).
[630895] <msg 17,25,71
<ver1.0.0h-beat10buff-in256devESP8266buildJun 27 2016 18:56:31
[632517] >msg 0,25,200
[634292] >msg 20,1,10

Winner Winner Chicken Dinner!

I would have gotten to this eventually, thanks for putting a fire under my keyboard!

Thanks Craig!

Moving to resolved.


I guess I don’t have the ‘resolved’ spell.

Benny please move this to reslolved.

@kreggly set me right.


Archived…unarchived…closed…opened. I love it lol.

I just created a resolved category for Arduino Beta :slight_smile:


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Just because I don’t know what I’m doing isn’t an excuse for not stabbing at every button available.

Probably why I let smoke out of so much stuff.

Thanks Benny!


The request for the analog value happens about every 2 seconds, so you don’t need any delays in your main loop.

Also, I’m writing a median filter to take a bunch of measurements, sort them, then pluck the middle one. This helps when you get bad reads and don’t want them to average. There are some libraries, but they don’t want to work right. Simple enough to throw together something (or steal it).


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