XIAO RP2040 Schematic appears incomplete / outdated

Hi, it appears that the v1.08 schematic linked from the XIAO RP2040 product page is missing some connections, eg it doesn’t show one of the user LEDs on GPIO25, and I’m not sure if the others are there or not as only ‘Yellow LED’ is listed on GPIO18 and when I toggle this there is no LED affected by it, I presume it’s not connected on this board version. Further more, The v1.10 schematic linked from the wiki, which I think might be a closer match to my actual board revision, is broken and can’t be downloaded. The live schematic viewer on the wiki page is also broken.
Is it possible to get the latest, correct schematic for the currently shipping boards?

Thanks

I had the same problem with the Wiki link a couple of days ago, but I just now checked it again and: Taa Daa! It’s better.

(As a new user, I can’t upload the file here, but the last time I checked, the file is XIAO-RP2040-v1.10-SCH&PCB.zip)

Version 1.10 shows a GREEN LED with signal named “USER_LED” that is connected to GPIO25, consistent with the definition of LED_BUILTIN in the variants\Seeed_XIAO+RP2040\pins_arduino.h file.

A “Blink” sketch that wiggles the LED_BUILTIN pin does affect that LED. (Low turns it on and high turns it off, as expected.) When I “Serial.print” the value of LED_BUILTIN it shows the correct GPIO pin number: 25.

However, I still see a problem with the two BLUE LEDs, which are shown connected to signals “TX” and “RX” that are connected to GPIO pins 0 and 1 (Arduino pins D6 and D7), respectively.

Now, here’s the thing: I can wiggle pins D6 and D7 from an Arduino sketch (observed on a 'scope, or with external LEDs connected to those pins—through appropriate resistors), and I don’t see any effect on those two LEDs.

Bottom line: In case any Seeed support people monitor this forum, I echo your question: Is it possible to get the latest, correct schematic?

Regards,

Dave

Hi, thank you for your feedback. At present, the self-inspection found that the schematic diagram of the product detail page of XIAO RP2040 is v1.08. We will update the download link above as soon as possible. You can check the latest v1.10 schematic diagram from the wiki first, thank you.
https://wiki.seeedstudio.com/XIAO-RP2040/

The LED part of the V1.0 circuit diagram is also strange.
On the board I got
The red LED of Tx is GPIO17
Rx green LED is GPIO16
Is connected to.
In the V1.0 schematic, the Eagle PCB is also different from the actual one, and Tx is directly connected to GPIO0.

Perhaps the design was changed along the way.

1 Like

Hello everyone, subject to the latest circuit diagram

Hi @Citric, there’s still a problem with the latest schematic - the RX LED and TX LED pin assignments are incorrect as per k_akiba’s post. I can confirm they are not on GPIO0 and GPIO1. Toggling GPIO16 and GPIO17 does blink them though, however v1.10 schematic has these as unassigned.

Edit: also noting that the board image on the wiki shows a red, green, and blue USER LEDs instead of 2 blue LEDs for RX and TX, which seems to be correct for my XIAORP2040 boards but disagrees with this schematic still

1 Like

Thank you for your feedback. I will check it as soon as possible. If the problem does exist, a new version update will be released as soon as possible. Please wait a moment, thank you

The investigation of the problem is clear. There are two versions of XIAO RP2040 in history. The old version of XIAO RP2040 does have TX LED and RX LED. But in the new version of XIAO RP2040, these two lights are cancelled. The latest schematic has been uploaded to the product detail page and Wiki. Thanks again for your feedback.

1 Like

Hi @Citric, I notice the link has been updated to schematic versions 1.22, thank you! The online viewer above it is still showing the v1.10 schematic though. If there multiple board revisions in distribution maybe all schematic versions should be listed for download with the latest or most common version displayed in the online viewer?

Thanks again and happy new year!

The link to the product details has been updated and I am confused

Hi @Citric,

The link has been updated, yes. And it is correct on the product page and the wiki. Thank you.

The wiki has another reference to the schematic though in the ‘online schematic viewer’ which can be found here: https://wiki.seeedstudio.com/XIAO-RP2040/#schematic-online-viewer
The version used there is still v1.10 and not v1.22

Well, I have contacted my colleague to finish the modification in the morning

It looks like it’s been updated just now - thanks again!

All drawings have been updated to the wiki and product detail pages, you can download them yourself

I think that last post is a spam bot copying Dave’s earlier post to this thread verbatim then adding a spammy link to the bottom…

1 Like