need advice

[mustafasei]

Hi

 I'm new user for Labview and arduino and recently start to use the arduino with labview via Linx firmware and labview 2013 and doing some small projects or experiments but i have some difficulties with some sensors of arduino which i have it now the 37 kit like the 18B20 and DHT11 and so.

I have no idea about the arduino programming language C++ which is I'm totally far away from it.

i need your support for how to define some of the arduino sensors to be known in labview menu  like (makerhub-linx-sensors-temp-tmp3x)

i have searched in makerhub forums and got answer that i have to use the custom command which is something i cannot use due to my poor ability in C++.

 

please advise

[mustafasei]

When I use the arduino code for the DHT11 it works good but when i use the Labview VI in examples not work and give me the error above

[AustinStanton]

You should be able to use those directions to guide you in making another custom command. If you get stuck at any part you can ask and I will try my best to talk you through it.

[mustafasei]

Hi Austin

 Is it possible to use your instructions above as a standard form for any kind of codes ?

i have some codes in this page http://www.locobots.com/node/24 and I want to use one of them ( Knob control and DVD tray stepper:) as custom command , is it same procedure or there  will be some differences

 

 

[AustinStanton]

Glad to hear, let me now if you want me to explain the Arduino or LabVIEW code in greater detail. 

-Austin

[mustafasei]

Thank you very much for your support.

it is work now and every thing is OK

 

[AustinStanton]

Once you have the "Arduino_Uno_Serial" example opened go to Sketch-> Include Library->Manage libraries. In the library manager search "DHT sensor library", once it comes up click on it and then select the install button that pops up. After it is installed restart Arduino IDE and then reopen "Arduino_Uno_Serial"

Now click File-> save as and then save it with a name like "DHT". This way you don't make any changes to the template. 

Once your new file is opened add the DHT library by putting 

#include <DHT.h> 

Then add 

int dht();

Next add the following code to the setup() function to attach the custom command to the LINX listener (in this case called LinxSerial connection)

 LinxSerialConnection.AttachCustomCommand(2, dht);

Finally at the bottom of the firmware, after the void loop, add your custom function. The custom function that will work with "LINX interactions DHT11.vi" example in Labview is pasted below. 

int dht(unsigned char numInputBytes, unsigned char* input, unsigned char* numResponseBytes, unsigned char* response)
{
  if (numInputBytes != 1)
  {
    return 1;
  }

  DHT dht(input[0], DHT11);

  dht.begin();
  delay(1000);

  unsigned char h = dht.readHumidity();
  // Read temperature as Celsius (the default)
  unsigned char t = dht.readTemperature();
  // Read temperature as Fahrenheit (isFahrenheit = true)
  unsigned char f = dht.readTemperature(true);

  // Check if any reads failed and exit early (to try again).
  if (isnan(h) || isnan(t) || isnan(f)) {
    return 1;
  }

  unsigned char hif = dht.computeHeatIndex(f, h);
  // Compute heat index in Celsius (isFahreheit = false)
  unsigned char hic = dht.computeHeatIndex(t, h, false);

  response[0] = h;
  response[1] = t;
  response[2] = f;
  response[3] = hic;
  response[4] = hif;

  *numResponseBytes = 5;

  return 0;
}

I have attached my code as well so you can copy and paste from there or use it if you would like. Once you are finished, upload the code to your board and then you will be able to use the LINX DHT11 example. 

DHT_example.ino

 

[AustinStanton]

Ok so I am going to walk you through the process of writing a custom command for the DHT11.

Before we start 

1) Generated the LINX firmware libraries in the appropriate location for Arduino IDE

• do this by opening LabVIEW and under the Tools tab go to MakerHub –> LINX –> Generate Firmware Libraries

 

2) Then restart arduino IDE and then in the arduino IDE open the LINX example for the Arduino uno

• This will open us a template for making a custom command

Once you have done that I will tell you how you can modify it to use it with the DHT11

 

[mustafasei]

Arduino Uno

[AustinStanton]

I am going to try and test it out and I will get back to you, which board are you using?

[mustafasei]

When I use the arduino code for the DHT11 it works good but when i use the Labview VI in examples not work and give me the error above

 

any idea

[mustafasei]

I tried all above and nothing new just the same error message which I attached before.

[AustinStanton]

Have you gotten the Interactions DHT to work yet?

If not here are a few things you should do

• Make sure you are using the right COM port 
• Make sure you have the correct DHT data pin selected
  • Maybe try a few different pins 
• Use LINX firmware wizard to reload LINX firmware onto your board

Try these things and let me know what happens, you shouldn't need to paste your code anywhere to make this VI work. 

 

[mustafasei]

Any advice please 

[mustafasei]

 

 

13 hours ago, AustinStanton said:

Actually, the DHT11 already has a Sub Vi. Open LabVIEW and go to Help>Find Examples and search DHT11, "LINX- Interactions DHT11.vi" will pop up. That is an example showing you how to read the DHT11 sensor. From the block diagram of a VI you can find the Read block for the DTH11 by right clicking to open the functions palette and then selecting Makerhub>LINX>Sensors>Digilent>Interactions>DHT11 Read. 

 Which other sensors do you need help with? 

 

13 hours ago, AustinStanton said:

I found the DHT11.vi  in the examples and run it but i got the error message as attached ,and regarding the function palette I didnt found the Digilent>interaction>DHT11 Read 

any advice  

13 hours ago, AustinStanton said:

Actually, the DHT11 already has a Sub Vi. Open LabVIEW and go to Help>Find Examples and search DHT11, "LINX- Interactions DHT11.vi" will pop up. That is an example showing you how to read the DHT11 sensor. From the block diagram of a VI you can find the Read block for the DTH11 by right clicking to open the functions palette and then selecting Makerhub>LINX>Sensors>Digilent>Interactions>DHT11 Read. 

 Which other sensors do you need help with? 

Hi

 Thank you for your replay, I'm still struggle for building a custom command due to my very poor experience in C++.

I have seen the makerhub which you send to me many times but I have no idea how to copy and paste my codes of arduino sensors which i have in my 37 sensor kit

so let us say in this way :

if i have the below code for the DHT11:

(

#include <dht.h>
 

 
#define dht_apin A0 // Analog Pin sensor is connected to
 
dht DHT;
 

void setup(){
 
  Serial.begin(9600);
 
  delay(500);//Delay to let system boot
 
  Serial.println("DHT11 Humidity & temperature Sensor\n\n");
 
  delay(1000);//Wait before accessing Sensor
 
}//end "setup()"
 

 
void loop(){
 
  //Start of Program
 
  DHT.read11(dht_apin);
 

 
    Serial.print("Current humidity = ");
 
    Serial.print(DHT.humidity);
 
    Serial.print("%  ");
 
    Serial.print("temperature = ");
 
    Serial.print(DHT.temperature);
 
    Serial.println("C  ");
 
  delay(5000);//Wait 5 seconds before accessing sensor again.
 
  //Fastest should be once every two seconds.
 
}// end loop()

)

where shall i past the above code on what has explained in makerhub website for how to create the custom command

thanx

 

[AustinStanton]

This is another custom command example 

https://www.labviewmakerhub.com/doku.php?id=learn:tutorials:libraries:linx:misc:custom_command_example&s[]=write&s[]=custom&s[]=command

[AustinStanton]

First make sure to generate the LINX firmware libraries in the appropriate location for your device's IDE by opening LabVIEW and under the Tools tab go to MakerHub –> LINX –> Generate Firmware Libraries. Then restart arduino IDE and then in the arduino IDE open the LINX example for the device and interface you're using. (ex. File»Examples»LINX»Arduino_Uno_Serial). This will open up a template for making a custom command. The Makerhub link I sent you goes over the basics of where things go but I have attached an example of a custom DHT11 command, this command was written for the WF32 so the beginning will be different because it calls different libraries but it will help you understand where the custom code goes. 

Let me know if you have any more questions

 

DHT.ino

[mustafasei]

Hi

 Thank you for your replay, I'm still struggle for building a custom command due to my very poor experience in C++.

I have seen the makerhub which you send to me many times but I have no idea how to copy and paste my codes of arduino sensors which i have in my 37 sensor kit

so let us say in this way :

if i have the below code for the DHT11:

(

#include <dht.h>
 

 
#define dht_apin A0 // Analog Pin sensor is connected to
 
dht DHT;
 

void setup(){
 
  Serial.begin(9600);
 
  delay(500);//Delay to let system boot
 
  Serial.println("DHT11 Humidity & temperature Sensor\n\n");
 
  delay(1000);//Wait before accessing Sensor
 
}//end "setup()"
 

 
void loop(){
 
  //Start of Program
 
  DHT.read11(dht_apin);
 

 
    Serial.print("Current humidity = ");
 
    Serial.print(DHT.humidity);
 
    Serial.print("%  ");
 
    Serial.print("temperature = ");
 
    Serial.print(DHT.temperature);
 
    Serial.println("C  ");
 
  delay(5000);//Wait 5 seconds before accessing sensor again.
 
  //Fastest should be once every two seconds.
 
}// end loop()

)

where shall i past the above code on what has explained in makerhub website for how to create the custom command

thanx

 

[AustinStanton]

Actually, the DHT11 already has a Sub Vi. Open LabVIEW and go to Help>Find Examples and search DHT11, "LINX- Interactions DHT11.vi" will pop up. That is an example showing you how to read the DHT11 sensor. From the block diagram of a VI you can find the Read block for the DTH11 by right clicking to open the functions palette and then selecting Makerhub>LINX>Sensors>Digilent>Interactions>DHT11 Read. 

 Which other sensors do you need help with? 

[AustinStanton]

https://www.labviewmakerhub.com/doku.php?id=learn:tutorials:libraries:linx:misc:adding_custom_command

That is a walkthrough showing how to add a custom command 

http://playground.arduino.cc/Main/DHT11Lib

That link will take you to a bunch of example code for the DHT11Lib 

https://blog.digilentinc.com/how-to-use-linx-custom-commands/

Finally this link is a blog post called "How to use LINX Custom Commands" 

Let me know if you have any problems figuring things out