Intel Joule interface voltages (UART, I2C, GPIO)

[EBabc]

I cannot figure out what voltage levels the various communication interfaces can accept on the logic lines on the Intel Joule 570x. I see that in general that there are 1.8V, 3.3V, and 5V buses, but I can't find anywhere in the documentation specifying what voltages the various interfaces can tolerate. I need to know if I will need a level shifter to communicate with my device. I have checked the documentation for both the Joule module and the expansion board, but I can't seem to find this information.

Thanks!

[idata]

Hello eab,

Thank you for interest in the Intel® Joule™ Products.

I understand that you are interested in knowing the respective operation voltages of each of the interfaces.

In the Intel® Joule™ Module – Datasheet (http://www.intel.com/content/dam/support/us/en/documents/joule-products/intel-joule-module-datasheet... http://www.intel.com/content/dam/support/us/en/documents/joule-products/intel-joule-module-datasheet...) you can see the following statement:

All I/O signals are 1.8V with the exception of USB and PCIe which adhere to their respective standards.

That document also mentions that the maximum electrical specifications are: 1.89 V and 300 mA.

Also, if you check the Intel® Joule™ Expansion Board – Design Guide (http://www.intel.com/content/dam/support/us/en/documents/joule-products/intel-joule-expansion-board-... http://www.intel.com/content/dam/support/us/en/documents/joule-products/intel-joule-expansion-board-...) you can see the following information that confirms the previous statement:

Unless otherwise noted, all I/O signals operate at 1.8 VDC (with the exception of industry standard buses and protocols) each which must operate within their defining specifications parameters.

All module GPIO lines function at 1.8 V levels. Intel® Joule™ expansion board provides appropriate level transition, signal conditioning, and protection for devices on-or devices connected to-the expansion board.

Please let me know if the previous information answers your question.

Regards,

Andres V.

[EBabc]

OK, that all makes sense to me until the very end there when you say:

Intel® Joule™ expansion board provides appropriate level transition, signal conditioning, and protection for devices on-or devices connected to-the expansion board.

Does that mean that the expansion board does level shifting for the I/O lines? I understand now that the Joule Module itself uses 1.8V for all I/O, but if I am using the expansion board can I provide other voltages, or should I provide my own level shifter to go from a 3.3V or 5V logic line down to 1.8?

Thanks.

[idata]

Hello ead,

Sorry for the confusion the previous post may have generated. Let me rephrase the information previously cited:All I/O signals from the compute module are 1.8 V (with the exception of USB and PCIe).On the other hand, all I/O signals from the expansion board are 3.3 V (and 5 V tolerant), thanks to the level transition, signal conditioning, and protection for devices.I hope that answers your question, please let me know if you need further assistance.Regards,Andres V.

[EBabc]

Great, thanks!

[YDesv]

Hello !

I don't understand very well... I have the expansion board too (installed with Intel module 570x, and Windows IoT), and i would like to know how to configure the board to have 3,3V for GPIO as ouput....

It's possible ???

Thanks for you time !

[idata]

Hello yoavdes,

As I mentioned before in this post, all I/O signals (keep in mind that GPIO stands for general-purpose input/output) from the expansion board are 3.3 V (by default). So you don't have to perform any additional configuration.

If you have any other question, don't hesitate to contact us.

Have a nice day.

Regards,

Andres V.