@felmue great! thank you so much for the data!

Most of my projects require devices that can achieve low power deep sleep modes so that they can last a long time on batteries. I had stopped using M5Stack products in the past solely because they had poor low power current consumption. Now that they've started using esp32-s3's I'm hopeful that I can use their products for low power applications. I would love to see a deep sleep current consumption of less than 1ma.

Anyone had a chance to measure the deep sleep current on an AtomS3 with everything powered off?

I've been working on getting the deep sleep current for the StickC Plus as low as possible. When powered via the StickC's internal battery, I can get the deep sleep current draw to about ~1ma.

However, whenever I power the StickC (or the Atom) via the USB-C connector, I can never get the deep sleep current draw to go any lower than 16mA.

Looking at the StickC schematic, I see that the USB-C IC and the USB to UART IC are always powered when USB is connected. I also see two resistor dividers for the ESP32_EN and GPIO0 signals which are also powered by VBUS_USB. The resistor dividers alone will cause a constant ~5mA current draw, so I assume the rest is coming from the other two IC's.

This is an issue as all of the M5 products that provide an external battery (TailBat, 18650C) appear to all provide power via the USB-C connector. This means that by just adding an external battery, you're adding an additional constant 15mA current draw, which kind of defeats the purpose for low power applications. The only way I've found around this is using the 5V input pin on the StickC, but that doesn't exist for the Atom.

Has anyone had any luck reducing the current draw when powered via USB-C?

@m5stack I'm just getting started with the UI-Flow firmware and am very interested in seeing more of it go open source, especially the the code for the Hats.

Any updates on open source plans?