<![CDATA[Stamp C3U - Maximum GPIO input voltage?]]>Hi,

I want to use the internal ADC of the Stamp C3U. What is the maximum voltage, that can be measured? 3,3V or 5V?
I don't understand the meaning of the feature "Stamp-C3 contains 5V->3.3V DC/DC design". Does it mean, that there is a level shifter? Or does it mean, that the inputs are 5V tolerant? Or does it just mean, that 5V are accepted as power input?

Thanks.

]]>https://community.m5stack.com/topic/4509/stamp-c3u-maximum-gpio-input-voltageRSS for NodeMon, 13 Apr 2026 23:52:12 GMTMon, 08 Aug 2022 08:49:42 GMT60<![CDATA[Reply to Stamp C3U - Maximum GPIO input voltage? on Mon, 08 Aug 2022 12:22:31 GMT]]>Hi Felix,
thank you for your fast reply.
I've used different Atmega, Attiny and STM32 based boards in the past, but new to ESP32. That's the reason for my "stupid" question. ;-)

Thanks again.

]]>https://community.m5stack.com/post/18244https://community.m5stack.com/post/18244Mon, 08 Aug 2022 12:22:31 GMT<![CDATA[Reply to Stamp C3U - Maximum GPIO input voltage? on Mon, 08 Aug 2022 09:26:06 GMT]]>Hello @o8of15

DC/DC design in this case means there is a DC/DC converter for the power input so the M5StampC3U can be powered by USB / 5V. However the GPIOs are all 'naked' - there are no level shifters. And no, in general ESP32 GPIOs are not 5 V tolerant - 3.3 V is the maximum.

Please also have a look at the schematic.

Thanks
Felix

]]>https://community.m5stack.com/post/18242https://community.m5stack.com/post/18242Mon, 08 Aug 2022 09:26:06 GMT