FRDM-KL25Z and P5V_USB

[chaegle]

I have been working with the Freedom board for some time now. Recently I was asked to develop a demo using this board.

My demo is making use of a couple of Arduino shield and in order for viewers to better see what exactly is being used I have had a larger breakout board built, whereby I can unstack the boards and lay them all out, side-by-side. I am powering up the Freedom board via J9-20 (5V-9VIN). One of my shields is expecting 5V on J9-10 (5V_USB). Looking at the available documentation it is apparent that J9-10 gets voltage off of either the USB_SDA or USB_KL25Z connectors.

Here is my question, provided my shield can accomodate 5-9V, which it can, are there any issues with my simply tying J9-10 to J9-20? From what I see J9-10 does not seem to be connected to much of anything on the Freedom board, aside from the Shottky diodes, off P5V_SDA and P5V_KL25Z.

Thanks,

Cameron

[BlackNight · Accepted solution]

Yes, I had the same issue using 'normal' shields which do need that 5V from the CPU board. The current FRDM board does not generate/provide that 5V.

As long as you get exactly that 5V through VIN, I do not see an issue connecting VIN with the 5V pin. What I'm using with my boards is S7V7F5 DC-DC step up/down voltage converter board from Pololu which generates 5V from 2.7..11.8V. Ideal for battery voltage coming from VIN. See Zumo Line Following with FRDM-KL25Z for details. I use the same concept for other shields.