xDot Programming trouble

[Chad Goyette]

I am trying to program an xDot on a custom PCB and I am having some trouble. I have the programming header installed as per the dev guide. How do i know if i am actually connected to the target vs the xDot on the DK? In the Dev guide the illustrations show JP1 being the connector closest to the center, but on the board JP1 is the connector on the edge Which is the correct one? also there is no label for pin 1 on the DK.

[Tom Swanson]

Hi Chad,

The developer guide is correct; JP1 is the 9-pin header that is closest to the center of the board. The early development samples of this board had these headers mislabeled on the PCB silkscreen, and you must have received one of these early boards. I apologize for the confusion.

Pin 1 of JP1 is the pin that is closest to the corner of the board. If you hold the board with the USB connector pointing up, pin 1 is in the bottom-right corner of JP1. If you use the keyed 9-pin programming cable and you follow our pinout recommendations on your custom PCB, everything should plug together the right way automatically.

To verify that you are connected to your custom board (and not the onboard xDot), you can remove the jumper from header JP30 and place it on header JP5. This un-powers and isolates the onboard xDot. Connect your custom board, and then unplug and re-plug the xDot DK from USB. If the USB drive shows up as “XDOT,” then it must be talking to your custom board. If it shows up as “MAINTENANCE,” then there’s still an issue somewhere. Note that your custom board will need to be powered up before plugging the xDot DK into USB.

Please let me know if there is anything else that I can help clarify.

Regards,
Tom

[Chad Goyette]

Tom I finally got around to trying your recommendation and I am finding that this procedure is not working correctly. I swapped the JP30 jumper to JP5 plugged in the programming head as you specified and made sure that my target board was powered up and confirmed that power was seen on the UDK before plugging it into the USB. When I plug the UDK in the USB drive shows up as maintenance so my first thought was we have a problem. We looked through our schematics and we are sure that we are connected correctly based on the information in the developers guide. I am also confident that our xdot connection to the interface board is good.

As a work around I installed the JP5 jumper back onto JP30 then I tried installing a simple “Hello World this is the UDK” program on the UDK with nothing hooked up to it. I then hooked up my powered target device and reset the USB connection then installed a “Hello World this is the target device” program. after confirming that this program was properly sending messages to the serial console I then unhooked the target device reset the USB and opened the serial console which now displayed “Hello World this is the UDK” confirming that the first program was still on the UDK and the previous program was definitely on the target.

So lesson learned unless there is an other way to isolate the UDK xdot it would be good practice to have a warning program on the UDK running that the user can confirm through the serial console that they are not able to see the UDK message before programming the target.

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