QSPI Flash Access on Custom XIAO nRF52840 PCB

[willthree123]

Hi everyone,

I’ve been developing with the Seeed Studio XIAO nRF52840. Everything worked well during prototyping, so I moved on to creating my own custom PCB.

Now that I’ve received the PCB, I’ve successfully flashed the bootloader and can upload code via DFU using the Arduino IDE. However, I’m unable to access the onboard QSPI memory.

I’d like to ask for clarification on a few points:

1. From my research, it seems that the onboard memory is separate from the nRF52840 chip. Can anyone confirm if this is correct?
2. If it is a separate chip, where exactly is this memory stored?

• I’ve reviewed both the schematic and the footprint of the official XIAO nRF52840 board. I believe the memory is provided by the chip connected via the QSPI lines. Source
  

  

• However, in the schematic, the chip is only labeled as “DNP,” and I haven’t been able to identify the exact model.

Can anyone help me identify this QSPI flash chip or provide more details about it?

Thanks in advance for your support!

[msfujino]

I think it’s P25Q16H.

[PJ_Glasso]

crossed_fingers: i there,

So , as per usual @msfujino is correct…

If I may add, have a look at this code and thread on the Grove Expansion Board, It has a spot on the Bottom to Add additional Flash and I have done so. The Testing zcode would be helpful to you.
It tests both the Internal Flash, the External QSPI flash and the Solder-in Flash chip. I did both Nrf52840 & ESP32C3 vastly different configs for the SPI’s

Grove_expansion With Display and temp Probe

In the END i got it going with Excellent support from The seedineers, @Citric & @Seeed_Seraphina … Check out the complete flash testing Journey and it should be beneficial to you.

Seeed Studio Grove Base for XIAO (SPI Solution) SUCCESS!

This is a Very Nice board (maybe) [xiao_-Preview-251] and I recommend anyone planning on getting started use this. (or if you want the other AWESOME expansion board with display) Expansion Board Base for XIAO That being said. To whom it may concern, The link for documentation is broken in the WIKI? Can someone fix that and provide me the Proper documentation link and/or schematic, etc. I need to know 2 things: What is the part no. for the SOIC SPI FLASH chip on the Bottom. Please provi…

HTH
GL PJ

So in reviewing your open, and Without any code posted I’m betting this link has your answer, it’s subtle…very subtle
You’ll get it just read everything and stay with it.
also post the code if you can, use the code tags above “</>” and paste it in there. The SPI’s (including the QSPI) are slick and better than how the ESP32 monkeys doit. IMO.