How many PmodTC1 can run on WF32

[Marty]

How many PModTC1 units can run on a WF32?

 

Thanks

Marty

 

 

[JColvin]

Hi @Marty,

The answer depends on how determined you are to use all of the predesignated SPI pins that are available on the WF32. Base on how the SPI library is implemented, you can use any number of GPIO pins without needing to directly implement them as part of the SPI library commands; you just need to raise and lower the CS logic level as appropriate. With that in mind, you can probably use upwards of 10 modules without any issues.

The main two issues that you will run into will be the power requirements for running a lot of modules and the amount of data that you can receive within certain time frames; it looks like the conversion time for the module is about 100 ms.

Let me know if you have any other questions about this.

Thanks,
JColvin

[Marty]

I'm going to program in LABVIEW,  and I just ordered the PMOD shield.  Labview has a PMod example for the PmodTC1 where you can set SPI channel and CS (chip select). Lets say I want to use five PmodTC1 (connect them to JA thru JE)

 

1) can use all five PMod connectors (4-GPIO and 1-SPI) to do this?

2) where    are SPI channel and CS ( Chip select) configured on the board?

 

thanks

Marty

 

[Marty]

Please  correct me or comment. 

It seems the WF32 was only intended for the user to utilize ONE SPI external device.  In section 10.2, a total of four are mentioned, though one is for wifi.   BUT, when you look at the pin out table (section 12.3) SPI is only defined for one usage.   My mistake obviously to assume you can scale up to more than one SPI channel with simple changes in code. Oh well, live and learn. 

If I'm wrong about this.  Then will the labview software properly route SPI communication to SP2 if I define my SPI channel as 2?

 

   

[Marty]

Sorry ment chip select not SPI channel, when I get my stuff I'll play with  changing chip select in labview to see what line toggles on the board

[Marty]

On 6/15/2018 at 5:01 PM, JColvin said:

Hi @Marty,

The answer depends on how determined you are to use all of the predesignated SPI pins that are available on the WF32. Base on how the SPI library is implemented, you can use any number of GPIO pins without needing to directly implement them as part of the SPI library commands; you just need to raise and lower the CS logic level as appropriate. With that in mind, you can probably use upwards of 10 modules without any issues.

The main two issues that you will run into will be the power requirements for running a lot of modules and the amount of data that you can receive within certain time frames; it looks like the conversion time for the module is about 100 ms.

Let me know if you have any other questions about this.

Thanks,
JColvin

Ok now that my hands are getting dirty I think I know why you said 10, cause there are 9 free di/do plus CS availible (44).  true?  thanks

[jpeyron]

Hi @Marty,

Correct, I believe that was why  @JColvin  stated 10.

thank you,

Jon