Seeed Studio XIAO SAMD21: The Smallest Arduino Microcontroller, 100% Arduino IDE Compatible, Pre-Soldered, USB Type-C, Battery Included

Q: Can i attach voltage in to the 5v pin? i'm trying to put this on a pcb. will it have the same voltage regulation?

As a previous contributor wrote: a lot of people answering questions here do not know what they are talking about! So here is the answer copied straight from the Seeed Studio webpage regarding this board: "Note For general I/O pins: Working voltage of MCU is 3.3V . Voltage input connected to general I/O pins may cause chip damage if it' higher than 3.3V . For power supply pins: The built-in DC-DC converter circuit able to change 5V voltage into 3.3V allows to power the device with a 5V supply via VIN-PIN and 5V-PIN. Please pay attention to use, do not lift the shield cover."

Q: Does this come with a bootloader or not?

yes - I'm pretty sure it does. Its been a while since I played with it. But I seem to recall all was needed was to download the necessary Arduino files into the Arduino programming system and make the correct connection to the device. However be aware the device is finicky in that it needs to be rebooted for programming mode using a jumper wire. So if you're doing a lot of development/debugging, do that work in a standard Arduino first, and then translate your debugged program to this device.

Q: Is the IO 5V tolerant?

From the testing I have done on mine, the pins when being used as an input, are 3.3v tolerant.

Q: The board can be connected to 5V power supply and simultaneously been conectes to the usb conector from my computer?

There would be a problem if the 5V supply was actually a lower voltage than the USB (which should be 5V). A diode protects everything if the external 5V supply was above 5V (up to the 6V limit of the voltage regulator on the board). To be safe, a diode should be added in series with the external 5V supply. This protection is present in genuine Arduino boards' VIN pin.

Product ID: 442638319

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Details

Brand
seeed studio
Model Name
XIAO SAMD21
Ram Memory Installed Size
32 GB
Memory Storage Capacity
256 KB
CPU Model
MediaTek

Specifications

Processor	48 MHz MediaTek_MT8125
RAM	SRAM
Wireless Type	802.11b
Brand	seeed studio
Series	XIAO SAMD21
Operating System	Arduino
Item Weight	0.176 ounces
Product Dimensions	0.79 x 0.69 x 0.69 inches
Item Dimensions LxWxH	0.79 x 0.69 x 0.69 inches
Processor Brand	Microchip Technology
Number of Processors	1
Manufacturer	seeed studio
ASIN	B0B15B869W
Country of Origin	China
Date First Available	May 12, 2022