"The voltage source on the pull-up resistor must be derived from or controlled by the power supplied on the USB cable such that when VBUS is removed, the pull-up resistor does not supply current on the data line to which it is attached." —USB 2.0 Specification, section 7.1.5 How do I do that? If yo...

Four months ago the status of the ESP32-S2-SOLO(-U) and ESP32-S2-MINI-1(U) modules was changed to "Not recommended for new designs", with their replacements being the new ESP32-S2-SOLO-2(U) and ESP32-S2-MINI-2(U) modules which integrate the "ESP32-S2 ECO1 with improved RF performance". But now, four...

SPI on the ESP32-S2 can be somewhat confusing. There are four SPI peripherals yet only three SPI buses, and each bus can support multiple slave devices using chip selects (up to 11 slaves total across the three buses): SPI0 and SPI1 control the same spi bus, which uses the "SPI" prefix for its signa...

The changes I've spotted: Pins 17-22 of the module (SHD/SD2, SWP/SD3, SCS/CMD, SCK/CLK, SD0/SD0, SDI/SD1) have been disconnected, since the corresponding esp32 pins are already used for the module's integrated flash and psram. Previously the datasheet merely stated these pins "are not recommended fo...

Based on some googling this looks like this board is a "LilyGo SIM800L IP5306" ? Its schematic shows the button is not connected to any GPIO, it connects (via R57) to the KEY pin of its IP5306 PMIC (controlling power on/off). It also connects (via R53) to the enable/reset input of the ESP32.

The esp32-s2/s3 usb phy does not appear to handle the ID and V BUS pins like you'd normally expect from an integrated phy. It seems that most of the control signals of the usb core's phy interface are instead just hooked up to the gpio matrix: ~/.../esp-idf/components$ grep -P 'USB_(OTG|SRP)_' soc/e...