I2C MyRio Labview HIH-Honeywell sensor

[Tung_nguyen]

Hi everyone, 

i am new to the group. I just had issues entering command mode with the sensor HIH-8000( i'm using labview myRio I2C for the project). 

It is said: Start_CM command has to be sent before 10ms Command window expired. I tried to send Start_CM command but the sensor stay remain in normal mode. So i think the problem is 10ms Command window, i don't know how to get through this with labview. 

I am out of ideas how to create VI for this command mode. 

Thank you for your help, have a nice day guys. 

p/s: here is the datasheets for my sensor: https://www.digikey.de/short/4qqf1t

[Bob_Schor]

When attaching code (especially for an RT system such as a myRIO), it is especially helpful to attach the entire Project (which provides such things as the TypeDefs you use) and potentially lets those of us with myRIOs to watch your code run.  If you compress the folder holding your Project files, you can attach the resulting .ZIP file.

Some questions:

• Do you have previous experience using I²C or SPI Protocols?  [I have experience with SPI, including with the myRIO, but not I²C -- does it matter to you which protocol you use?].
• What are you trying to accomplish?  Explain in broad strokes (such as "I want to make one Temperature reading every 5 seconds and display it on the Front Panel").  

Bob Schor

[Tung_nguyen]

yeah sorry, i should do that. I have created many options, but i am experimenting on the file einfach_state.vi if you want to take a look. 

Thank you for your answer, i am a bit helpless now becouse this project took me almost 1 week now. 

[Tung_nguyen]

about your questions, 

1. I am new to this thing, my job requires me to learn and make it work quickly. And for this HIH8000 sensor, i have to use I2C protocols, because that is the way the sensor communicates. I have not tried SPI yet.

2. I want to make the mearsurements of Humidity and Temp by using this HIH8000 Sensor by using combined I2C format. Did not come to that part yet, need to connect 2 sensors into 1 myRio. 

[Bob_Schor]

In Windows 10, if you right-click a Project Folder (e.g. HIH8000) and choose the option "Compress Folder", you will get a .zip file, one that Windows 10 can open without needing third-party software that can handle a .7z file.

I did manage to open your .7z file.  I'm puzzled by the structure that I see.  There appear to be two separate Projects, one a myRIO Project called HIH8000, which references a myRIO "NI-myRIO-1900-031f4c63", which I assume is your myRIO.  Curiously, expanding this part of the Project did not show an entry called "Chassis" that, when expanded, has the Project description of the myRIO hardware, connectors, and (most important!) the FPGA.  

I think, if you want to build a myRIO Project that uses the myRIO Toolkit functions and allows you to program the FPGA  yourself, you should create a new myRIO Project and choose the myRIO Custom FPGA Project.  

Here's my suggestion:

1. Rename your existing HIH8000 folder to something else.'
2. Open LabVIEW 2018 (you seem to be using this Version of LabVIEW).
3. Create a New myRIO Project from the myRIO Template.  Choose the myRIO Custom FPGA Project.  Name the Project HIH8000 (or whatever else you want to use).
4. Because you are building a Custom FPGA Project, the setup time may take about a minute.  However, you should get a new blank Project that looks a bit like the image below from my PC (I'm connected by WiFi to the myRIO).
5. Now you have to get your existing code into one of three "buckets".  Here is how I would do this:
   1. I use "Physical Folders" and bring them into the Project as "Virtual Folders".
   2. Accordingly, I'd make three folders, "Host", "Target", and "FPGA".  The "Host" folder goes into the Project under the top "My Computer" section.  The "Target" folder goes into the myRIO (and includes "RT Main" or whatever you call the Top-Level VI running on the myRIO.
   3. Finally, expand the "Chassis" (which includes all of the myRIO's connectors, and a folder called "Sub VIs" where you put the FPGA code.  

Note that if you do not want to use custom FPGA, you can create a simpler myRIO Project that just needs Host and Target folders, and uses the I²C Express VIs that come with the myRIO Software Toolkit.

 Bob Schor

Ah!  It has been "separated" into a stand-along Project called FPGA-1!  

Here's what I suggest.  Rename the old HIH8000 Project file to something else.  Create a new myRIO Project called HIH8000.