Flashing to nRF5340 IO Shield.

[SohamGhugare]

Hello,

So I have an IO Shield with the nRF5340 SoC. I have connected the IO Shield to the Port 12 of the nRF5340 Audio DK as shown in the schematic:

Connections:

Debugging Port 12-

DK Board P12 Connector      Custom Board Debug Connector
------------------------------            ------------------------
Pin 1 (VTref)                       -> VDD (Power Supply Reference)
Pin 2 (SWDIO)                   -> SWDIO
Pin 3 (GND)                       -> GND
Pin 4 (SWCLK)                  -> SWCLK
Pin 5 (GND)                       -> GND
Pin 6 (SWO)                       -> P0.11
Pin 7 (NC)                          -> NC (No Connection)
Pin 8 (NC)                          -> NC (No Connection)
Pin 9 (GNDDetect)             -> NC (No Connection)
Pin 10 (nRESET).               -> nRESET

As mentioned in one of the threads, flashing the code should target the IO Shield if the connections are correct. However, when I tried flashing a simple Blinky program that will flash the LED on Pin 0.31 of the IO Shield, it didn't work. It rather started flashing the Blue LED on the Audio DK that is supposedly also on Pin 0.31. Am I missing something?

[Turbo J]

Most likely you are missing the required external power source.

Vtref is a sink and not a source for voltage.

[SohamGhugare]

Yeah we tried giving an external power source to VTref, that didn't work either. One thing which I noticed from the start that I forgot to mention is, no matter what program I flash, it always sets all the pins on IO Shield to high (atleast the pins we have connected). So even if I flash a normal blank program, the LED connected to P0.31 of IO Shield is always set to high.

PS: we are using MDBT53-P1M IO Shield.

[akhil]

SohamGhugare said:

VTref

VDD of I/O Shield